- arc improvements, fillets, operations, bodys

.idea/workspace.xml

@@ -4,13 +4,15 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="8f0bafd6-58a0-4b20-aa2b-ddc3ba278873" name="Changes" comment="- added contrain context menu&#10;- improved line pickability.">
+    <list default="true" id="8f0bafd6-58a0-4b20-aa2b-ddc3ba278873" name="Changes" comment="- added &quot;measurement lines&quot;">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/gui.ui" beforeDir="false" afterPath="$PROJECT_DIR$/gui.ui" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/gui_ui.py" beforeDir="false" afterPath="$PROJECT_DIR$/gui_ui.py" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/src/fluency/geometry_occ/kernel.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/geometry_occ/kernel.py" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/fluency/io/project_io.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/io/project_io.py" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/fluency/models/data_model.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/models/data_model.py" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/fluency/rendering/occ_renderer.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/rendering/occ_renderer.py" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/src/fluency/ui/dialogs.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/ui/dialogs.py" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/src/fluency/ui/main_window.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/ui/main_window.py" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/fluency/ui/viewer_widget.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/ui/viewer_widget.py" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -27,7 +29,7 @@
   <component name="Git.Settings">
     <option name="RECENT_BRANCH_BY_REPOSITORY">
       <map>
-        <entry key="$PROJECT_DIR$" value="single_window" />
+        <entry key="$PROJECT_DIR$" value="feature/surface-modifier-pyramid-patterns" />
       </map>
     </option>
     <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
@@ -47,46 +49,47 @@
     <option name="hideEmptyMiddlePackages" value="true" />
     <option name="showLibraryContents" value="true" />
   </component>
-  <component name="PropertiesComponent"><![CDATA[{
+  <component name="PropertiesComponent">{
-  "keyToString": {
+  &quot;keyToString&quot;: {
-    "Python.2dtest.executor": "Run",
+    &quot;Python.2dtest.executor&quot;: &quot;Run&quot;,
-    "Python.3d_windows.executor": "Run",
+    &quot;Python.3d_windows.executor&quot;: &quot;Run&quot;,
-    "Python.Unnamed.executor": "Run",
+    &quot;Python.Unnamed.executor&quot;: &quot;Run&quot;,
-    "Python.base.executor": "Run",
+    &quot;Python.base.executor&quot;: &quot;Run&quot;,
-    "Python.data_model.executor": "Run",
+    &quot;Python.data_model.executor&quot;: &quot;Run&quot;,
-    "Python.draw_widget2d.executor": "Run",
+    &quot;Python.debug_dragging.executor&quot;: &quot;Run&quot;,
-    "Python.draw_widget_solve.executor": "Run",
+    &quot;Python.draw_widget2d.executor&quot;: &quot;Run&quot;,
-    "Python.fluency.executor": "Run",
+    &quot;Python.draw_widget_solve.executor&quot;: &quot;Run&quot;,
-    "Python.fluencyb.executor": "Run",
+    &quot;Python.fluency.executor&quot;: &quot;Run&quot;,
-    "Python.gl_widget.executor": "Run",
+    &quot;Python.fluencyb.executor&quot;: &quot;Run&quot;,
-    "Python.gui_ui.executor": "Run",
+    &quot;Python.gl_widget.executor&quot;: &quot;Run&quot;,
-    "Python.kernel.executor": "Run",
+    &quot;Python.gui_ui.executor&quot;: &quot;Run&quot;,
-    "Python.main.executor": "Run",
+    &quot;Python.kernel.executor&quot;: &quot;Run&quot;,
-    "Python.meshtest.executor": "Run",
+    &quot;Python.main.executor&quot;: &quot;Run&quot;,
-    "Python.occ_renderer.executor": "Run",
+    &quot;Python.main_window.executor&quot;: &quot;Run&quot;,
-    "Python.occ_to_mesh.executor": "Run",
+    &quot;Python.meshtest.executor&quot;: &quot;Run&quot;,
-    "Python.render_backend.executor": "Run",
+    &quot;Python.occ_renderer.executor&quot;: &quot;Run&quot;,
-    "Python.side_fluency.executor": "Run",
+    &quot;Python.occ_to_mesh.executor&quot;: &quot;Run&quot;,
-    "Python.simple_mesh.executor": "Run",
+    &quot;Python.render_backend.executor&quot;: &quot;Run&quot;,
-    "Python.sketch.executor": "Run",
+    &quot;Python.side_fluency.executor&quot;: &quot;Run&quot;,
-    "Python.surface_modifier.executor": "Run",
+    &quot;Python.simple_mesh.executor&quot;: &quot;Run&quot;,
-    "Python.vtk_widget.executor": "Run",
+    &quot;Python.sketch.executor&quot;: &quot;Run&quot;,
-    "Python.vulkan.executor": "Run",
+    &quot;Python.vtk_widget.executor&quot;: &quot;Run&quot;,
-    "RunOnceActivity.OpenProjectViewOnStart": "true",
+    &quot;Python.vulkan.executor&quot;: &quot;Run&quot;,
-    "RunOnceActivity.ShowReadmeOnStart": "true",
+    &quot;RunOnceActivity.OpenProjectViewOnStart&quot;: &quot;true&quot;,
-    "RunOnceActivity.TerminalTabsStorage.copyFrom.TerminalArrangementManager.252": "true",
+    &quot;RunOnceActivity.ShowReadmeOnStart&quot;: &quot;true&quot;,
-    "RunOnceActivity.git.unshallow": "true",
+    &quot;RunOnceActivity.TerminalTabsStorage.copyFrom.TerminalArrangementManager.252&quot;: &quot;true&quot;,
-    "RunOnceActivity.typescript.service.memoryLimit.init": "true",
+    &quot;RunOnceActivity.git.unshallow&quot;: &quot;true&quot;,
-    "codeWithMe.voiceChat.enabledByDefault": "false",
+    &quot;RunOnceActivity.typescript.service.memoryLimit.init&quot;: &quot;true&quot;,
-    "git-widget-placeholder": "feature/surface-modifier-pyramid-patterns",
+    &quot;codeWithMe.voiceChat.enabledByDefault&quot;: &quot;false&quot;,
-    "last_opened_file_path": "/Volumes/Data_drive/Programming/fluency",
+    &quot;git-widget-placeholder&quot;: &quot;feature/occ-migration&quot;,
-    "node.js.detected.package.eslint": "true",
+    &quot;last_opened_file_path&quot;: &quot;/Volumes/Data_drive/Programming/fluency/src/fluency&quot;,
-    "node.js.selected.package.eslint": "(autodetect)",
+    &quot;node.js.detected.package.eslint&quot;: &quot;true&quot;,
-    "node.js.selected.package.tslint": "(autodetect)",
+    &quot;node.js.selected.package.eslint&quot;: &quot;(autodetect)&quot;,
-    "nodejs_package_manager_path": "npm",
+    &quot;node.js.selected.package.tslint&quot;: &quot;(autodetect)&quot;,
-    "settings.editor.selected.configurable": "project.propVCSSupport.DirectoryMappings"
+    &quot;nodejs_package_manager_path&quot;: &quot;npm&quot;,
+    &quot;settings.editor.selected.configurable&quot;: &quot;project.propVCSSupport.DirectoryMappings&quot;
   }
-}]]></component>
+}</component>
   <component name="QodanaReportsService">
     <option name="descriptions">
       <ReportDescription localRun="true" path="/private/var/folders/kg/zm48w_r96yb68mlbzvb9gtq40000gn/T/qodana_output/qodana.sarif.json" reportGuid="5f5b823c-c594-48c5-ae1f-062e30303918" reportId="fluency/qodana/2024-02-04" />
@@ -94,9 +97,9 @@
   </component>
   <component name="RecentsManager">
     <key name="CopyFile.RECENT_KEYS">
+      <recent name="$PROJECT_DIR$/src/fluency" />
       <recent name="$PROJECT_DIR$" />
       <recent name="$PROJECT_DIR$/src/fluency/rendering" />
-      <recent name="$PROJECT_DIR$/src/fluency" />
       <recent name="$PROJECT_DIR$/drawing_modules" />
       <recent name="$PROJECT_DIR$/modules" />
     </key>
@@ -440,31 +443,23 @@
       <option name="project" value="LOCAL" />
       <updated>1783976498520</updated>
     </task>
-    <task id="LOCAL-00041" summary="Improved render previews">
+    <task id="LOCAL-00041" summary="- added &quot;measurement lines&quot;">
       <option name="closed" value="true" />
-      <created>1784408804224</created>
+      <created>1785094789247</created>
       <option name="number" value="00041" />
       <option name="presentableId" value="LOCAL-00041" />
       <option name="project" value="LOCAL" />
-      <updated>1784408804224</updated>
+      <updated>1785094789248</updated>
     </task>
-    <task id="LOCAL-00042" summary="- added contrain context menu&#10;- improved line pickability.">
+    <task id="LOCAL-00042" summary="- added &quot;measurement lines&quot;">
       <option name="closed" value="true" />
-      <created>1784452692776</created>
+      <created>1785697123545</created>
       <option name="number" value="00042" />
       <option name="presentableId" value="LOCAL-00042" />
       <option name="project" value="LOCAL" />
-      <updated>1784452692776</updated>
+      <updated>1785697123545</updated>
     </task>
-    <task id="LOCAL-00043" summary="- added contrain context menu&#10;- improved line pickability.">
+    <option name="localTasksCounter" value="43" />
-      <option name="closed" value="true" />
-      <created>1784470032428</created>
-      <option name="number" value="00043" />
-      <option name="presentableId" value="LOCAL-00043" />
-      <option name="project" value="LOCAL" />
-      <updated>1784470032428</updated>
-    </task>
-    <option name="localTasksCounter" value="44" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">
@@ -485,6 +480,7 @@
     <ignored-roots>
       <path value="$PROJECT_DIR$/pythonProject" />
     </ignored-roots>
+    <MESSAGE value="- Added new componnt controls" />
     <MESSAGE value="- changing compos for sketches works" />
     <MESSAGE value="- changing compos including sketches and bodies" />
     <MESSAGE value="- Drawing bodys depending on the selected compo&#10;- Cut working&#10;- Edit sketch working" />
@@ -508,8 +504,7 @@
     <MESSAGE value="-  added renderer" />
     <MESSAGE value="-  added renderer&#10;- Added undo" />
     <MESSAGE value="- Render improvements, camera plane, update" />
-    <MESSAGE value="Improved render previews" />
+    <MESSAGE value="- added &quot;measurement lines&quot;" />
-    <MESSAGE value="- added contrain context menu&#10;- improved line pickability." />
+    <option name="LAST_COMMIT_MESSAGE" value="- added &quot;measurement lines&quot;" />
-    <option name="LAST_COMMIT_MESSAGE" value="- added contrain context menu&#10;- improved line pickability." />
   </component>
 </project>

src/fluency/geometry_occ/kernel.py

@@ -235,6 +235,93 @@ class OCGeometryKernel(GeometryKernel):
             pass
         return None
 
+    @staticmethod
+    def find_coplanar_face(
+        shape: Any,
+        origin: Tuple[float, float, float],
+        normal: Tuple[float, float, float],
+        ref_center: Optional[Tuple[float, float, float]] = None,
+        angle_tol_deg: float = 5.0,
+        dist_tol: float = 1e-3,
+    ) -> Optional[Tuple[Any, Tuple[float, float, float]]]:
+        """Find a planar face on *shape* coplanar with the given plane.
+
+        Iterates the faces of *shape* and returns the first planar face whose
+        plane normal is parallel to *normal* (within *angle_tol_deg* degrees)
+        and whose plane passes through *origin* (within *dist_tol* distance).
+        When several faces match, the one whose surface centre is closest to
+        *ref_center* (if provided) is preferred.
+
+        Returns ``(face, center)`` where *center* is the surface centroid as a
+        3-tuple, or *None* if no matching face is found.
+        """
+        import math
+
+        from OCP.TopExp import TopExp_Explorer
+        from OCP.TopAbs import TopAbs_FACE
+        from OCP.TopoDS import TopoDS
+        from OCP.BRepAdaptor import BRepAdaptor_Surface
+        from OCP.GeomAbs import GeomAbs_Plane
+        from OCP.BRepGProp import BRepGProp
+        from OCP.GProp import GProp_GProps
+
+        import numpy as np
+
+        if shape is None:
+            return None
+        n = np.asarray(normal, dtype=float)
+        n = n / (np.linalg.norm(n) + 1e-30)
+        ox, oy, oz = origin
+
+        cos_tol = math.cos(math.radians(angle_tol_deg))
+        candidates: list = []
+
+        explorer = TopExp_Explorer(shape, TopAbs_FACE)
+        while explorer.More():
+            face = TopoDS.Face_s(explorer.Current())
+            try:
+                surf = BRepAdaptor_Surface(face)
+                if surf.GetType() != GeomAbs_Plane:
+                    explorer.Next()
+                    continue
+                plane = surf.Plane()
+                pn = np.array(
+                    [
+                        plane.Axis().Direction().X(),
+                        plane.Axis().Direction().Y(),
+                        plane.Axis().Direction().Z(),
+                    ],
+                    dtype=float,
+                )
+                # Check normals parallel (same or opposite direction)
+                cos_angle = abs(float(np.dot(n, pn)))
+                if cos_angle < cos_tol:
+                    explorer.Next()
+                    continue
+                # Check distance from plane to origin
+                pp = plane.Location()
+                d = abs(float(np.dot(n, np.array([pp.X() - ox, pp.Y() - oy, pp.Z() - oz]))))
+                if d > dist_tol:
+                    explorer.Next()
+                    continue
+                # Surface centroid via GProp (SurfaceProperties for faces)
+                props = GProp_GProps()
+                BRepGProp.SurfaceProperties_s(face, props)
+                c = props.CentreOfMass()
+                center = (float(c.X()), float(c.Y()), float(c.Z()))
+                candidates.append((face, center))
+            except Exception:
+                pass
+            explorer.Next()
+
+        if not candidates:
+            return None
+        if ref_center is not None and len(candidates) > 1:
+            rc = np.asarray(ref_center, dtype=float)
+            best = min(candidates, key=lambda fc: float(np.linalg.norm(np.asarray(fc[1]) - rc)))
+            return best
+        return candidates[0]
+
     def revolve(
         self,
         sketch: GeometryObject,
@@ -368,10 +455,11 @@ class OCGeometryKernel(GeometryKernel):
         else:
             from OCP.TopExp import TopExp_Explorer
             from OCP.TopAbs import TopAbs_EDGE
+            from OCP.TopoDS import TopoDS
 
             explorer = TopExp_Explorer(shape, TopAbs_EDGE)
             while explorer.More():
-                fillet.Add(radius, explorer.Current())
+                fillet.Add(radius, TopoDS.Edge_s(explorer.Current()))
                 explorer.Next()
 
         fillet.Build()
@@ -780,67 +868,3 @@ class OCGeometryKernel(GeometryKernel):
 
         cg = props.CentreOfMass()
         return Point3D(cg.X(), cg.Y(), cg.Z())
-
-    def apply_surface_modifier(
-        self,
-        body_geometry: GeometryObject,
-        modifier_type: str = 'pyramid',
-        height: float = 2.0,
-        radius: float = 3.0,
-        spacing: float = 8.0,
-        num_rings: int = 3,
-    ) -> Optional[GeometryObject]:
-        """Apply a surface modifier to a body geometry.
-
-        Args:
-            body_geometry: The OCCGeometryObject to modify
-            modifier_type: Type of modifier ('pyramid', 'bump')
-            height: Height/depth of the pattern features
-            radius: Base radius of pattern features
-            spacing: Distance between pattern features
-            num_rings: Number of concentric rings
-
-        Returns:
-            Modified geometry, or None on failure
-        """
-        from fluency.geometry_occ.surface_modifier import SurfaceModifier
-
-        shape = self._get_shape(body_geometry)
-        if shape is None:
-            logger.error("No geometry found in body")
-            return None
-
-        modifier = SurfaceModifier()
-
-        try:
-            if modifier_type == 'pyramid':
-                result_shape = modifier.apply_pyramid_pattern(
-                    shape,
-                    pyramid_height=height,
-                    base_radius=radius,
-                    spacing=spacing,
-                    num_rings=num_rings,
-                    direction=(0, 0, 1),
-                )
-            elif modifier_type == 'bump':
-                result_shape = modifier.apply_bump_pattern(
-                    shape,
-                    bump_height=height,
-                    bump_radius=radius,
-                    spacing=spacing,
-                    num_rings=num_rings,
-                )
-            else:
-                logger.error(f"Unknown modifier type: {modifier_type}")
-                return None
-
-            if result_shape is None:
-                logger.error("Surface modifier application failed")
-                return None
-
-            # Return the modified shape wrapped in OCCGeometryObject
-            return OCCGeometryObject(result_shape)
-
-        except Exception as e:
-            logger.error(f"Error applying surface modifier: {e}", exc_info=True)
-            return None

src/fluency/geometry_occ/surface_modifier.py

@@ -0,0 +1,385 @@
+"""Surface modifier for OpenCASCADE geometry.
+
+Applies geometric patterns (pyramids, bumps, grooves) to 3D surfaces using boolean operations.
+This enables grip-enhancing textures and visual surface modifications on CAD models.
+"""
+
+from __future__ import annotations
+
+import logging
+import math
+from typing import Any, Optional, Tuple
+
+# OCC imports at module level for common types
+
+
+logger = logging.getLogger(__name__)
+
+
+class SurfaceModifier:
+    """Applies geometric patterns to 3D surfaces using OCC boolean operations."""
+
+    def __init__(self):
+        self._patterns_applied = []
+
+    def apply_pyramid_pattern(
+        self,
+        face_shape,
+        pyramid_height: float = 1.0,
+        base_radius: float = 2.0,
+        spacing: float = 5.0,
+        num_rings: Optional[int] = None,
+        direction: Tuple[float, float, float] = (0, 0, 1),
+    ) -> Optional[Any]:
+        """Apply a pyramid pattern to a face surface.
+
+        Args:
+            face_shape: OCC TopoDS_Shape representing the face or solid
+            pyramid_height: Height of each pyramid
+            base_radius: Radius of pyramid base
+            spacing: Distance between pyramids
+            num_rings: Number of concentric rings (auto-calculated if None)
+            direction: Normal direction for pyramids
+
+        Returns:
+            Modified shape on success, None on failure
+        """
+        try:
+            from OCP.TopAbs import TopAbs_FACE
+            from OCP.TopoDS import TopoDS_Face, TopoDS_Shape
+            from OCP.BRepAlgoAPI import BRepAlgoAPI_Fuse
+            from OCP.TopExp import TopExp_Explorer
+            from OCP.BRepAdaptor import BRepAdaptor_Surface
+
+            # Validate face shape
+            if not isinstance(face_shape, (TopoDS_Shape, TopoDS_Face)):
+                logger.error("Invalid face shape type")
+                return None
+
+            # Extract the first face for surface parameterization
+            if isinstance(face_shape, TopoDS_Shape):
+                explorer = TopExp_Explorer(face_shape, TopAbs_FACE)
+                if not explorer.More():
+                    logger.error("No faces found in shape")
+                    return None
+                from OCP import TopoDS
+                face = TopoDS.TopoDS.Face_s(explorer.Current())
+            else:
+                face = face_shape
+
+            # Get face surface for UV parameterization
+            surf = BRepAdaptor_Surface(face)
+
+            u_min, u_max = surf.FirstUParameter(), surf.LastUParameter()
+            v_min, v_max = surf.FirstVParameter(), surf.LastVParameter()
+
+            # Calculate number of rings if not specified
+            if num_rings is None:
+                # Estimate based on face area and spacing
+                u_range = u_max - u_min
+                v_range = v_max - v_min
+                avg_dim = (u_range + v_range) / 2.0
+                num_rings = max(1, min(int(avg_dim / spacing), 5))
+
+            logger.info(
+                f"Applying pyramid pattern: {num_rings} rings, "
+                f"{base_radius:.2f} radius, {pyramid_height:.2f} height"
+            )
+
+            # Create pyramids distributed across the face UV space
+            result_shape = face_shape
+            pyramid_count = 0
+
+            for ring_idx in range(num_rings):
+                # Distribute rings evenly across UV parameter space
+                u_fraction = (ring_idx + 1) / (num_rings + 1)
+                v_fraction = 0.5  # Center vertically
+
+                # Map to actual UV coordinates on the face
+                u_pos = u_min + u_fraction * (u_max - u_min)
+                v_pos = v_min + v_fraction * (v_max - v_min)
+
+                # Get 3D position and tangent vectors at this UV point
+                from OCP.gp import gp_Pnt, gp_Vec
+
+                center_pt = gp_Pnt()
+                d1u = gp_Vec()
+                d1v = gp_Vec()
+                surf.D1(u_pos, v_pos, center_pt, d1u, d1v)
+                # Normal is cross product of tangent vectors
+                normal = d1u.Crossed(d1v)
+                normal.Normalize()
+
+                # Calculate number of pyramids in this ring based on spacing
+                if ring_idx == 0:
+                    num_pyramids = 1  # Center pyramid
+                else:
+                    circumference = 2.0 * math.pi * (ring_idx * spacing)
+                    num_pyramids = max(3, int(circumference / spacing))
+
+                for i in range(num_pyramids):
+                    if ring_idx == 0:
+                        # Center pyramid - place at face center
+                        place_u = u_pos
+                        place_v = v_pos
+                    else:
+                        angle = (2.0 * math.pi * i) / num_pyramids
+                        # Offset in UV space based on ring radius
+                        offset_u = (ring_idx * spacing / (u_max - u_min)) * math.cos(angle)
+                        offset_v = (ring_idx * spacing / (v_max - v_min)) * math.sin(angle)
+                        place_u = max(u_min, min(u_max, u_pos + offset_u))
+                        place_v = max(v_min, min(v_max, v_pos + offset_v))
+
+                    try:
+                        # Get 3D position and normal for this pyramid
+                        pyramid_pt = gp_Pnt()
+                        pd1u = gp_Vec()
+                        pd1v = gp_Vec()
+                        surf.D1(place_u, place_v, pyramid_pt, pd1u, pd1v)
+                        pyramid_normal = pd1u.Crossed(pd1v)
+                        pyramid_normal.Normalize()
+
+                        # Create solid pyramid at this position
+                        pyramid_shape = self._create_solid_pyramid(
+                            pyramid_pt,
+                            pyramid_normal,
+                            pyramid_height,
+                            base_radius,
+                        )
+
+                        if pyramid_shape is not None:
+                            # Fuse with existing geometry
+                            fuse = BRepAlgoAPI_Fuse(result_shape, pyramid_shape)
+                            fuse.Build()
+
+                            if fuse.IsDone():
+                                result_shape = fuse.Shape()
+                                pyramid_count += 1
+                            else:
+                                logger.warning(
+                                    f"Failed to fuse pyramid at ({place_u:.2f}, {place_v:.2f})"
+                                )
+                    except Exception as e:
+                        logger.debug(
+                            f"Error creating pyramid at ring {ring_idx}, pyramid {i}: {e}"
+                        )
+
+            self._patterns_applied.append(
+                {
+                    "type": "pyramid",
+                    "parameters": {
+                        "height": pyramid_height,
+                        "base_radius": base_radius,
+                        "spacing": spacing,
+                        "num_rings": num_rings,
+                        "direction": direction,
+                    },
+                }
+            )
+
+            logger.info(f"Successfully applied {pyramid_count} pyramids")
+
+            return result_shape
+
+        except Exception as e:
+            logger.error(f"Error applying pyramid pattern: {e}", exc_info=True)
+            return None
+
+    def _create_solid_pyramid(
+        self,
+        base_point,  # gp_Pnt - position on the face
+        normal_vec,  # gp_Dir or gp_Vec - surface normal direction
+        height: float,
+        base_radius: float,
+    ) -> Optional[Any]:
+        """Create a solid pyramid at the specified position and orientation.
+
+        Uses BRepPrimAPI_MakePrism to extrude a square base into a solid pyramid.
+
+        Args:
+            base_point: 3D point where pyramid base is centered
+            normal_vec: Direction vector for pyramid growth (surface normal)
+            height: Height of the pyramid from base to apex
+            base_radius: Half-width of the square base
+
+        Returns:
+            OCC solid shape for the pyramid, or None on failure
+        """
+        try:
+            from OCP.gp import gp_Dir, gp_Ax2, gp_Vec
+            from OCP.BRepBuilderAPI import (
+                BRepBuilderAPI_MakeEdge,
+                BRepBuilderAPI_MakeWire,
+            )
+            from OCP.BRepPrimAPI import BRepPrimAPI_MakePrism
+
+            half = base_radius / 2.0
+
+            # Build orthonormal basis from normal vector
+            if isinstance(normal_vec, gp_Vec):
+                n_dir = gp_Dir(normal_vec.XYZ())
+            else:
+                n_dir = normal_vec
+
+            # Create a local coordinate system at the base point
+            local_ax2 = gp_Ax2(base_point, n_dir)
+
+            # Get X and Y axes from the local coordinate system
+            x_dir = local_ax2.XDirection()
+            y_dir = local_ax2.YDirection()
+
+            # Create 4 corners of the square base in the local plane
+            corner_points = [
+                base_point + gp_Vec(x_dir).Multiplied(half) + gp_Vec(y_dir).Multiplied(half),
+                base_point + gp_Vec(x_dir).Multiplied(-half) + gp_Vec(y_dir).Multiplied(half),
+                base_point + gp_Vec(x_dir).Multiplied(-half) + gp_Vec(y_dir).Multiplied(-half),
+                base_point + gp_Vec(x_dir).Multiplied(half) + gp_Vec(y_dir).Multiplied(-half),
+            ]
+
+            # Create edges connecting the corners
+            wire_maker = BRepBuilderAPI_MakeWire()
+            for idx in range(4):
+                next_idx = (idx + 1) % 4
+                edge = BRepBuilderAPI_MakeEdge(
+                    corner_points[idx], corner_points[next_idx]
+                ).Edge()
+                wire_maker.Add(edge)
+
+            if not wire_maker.IsDone():
+                logger.warning("Failed to create pyramid base wire")
+                return None
+
+            # Extrude the base wire in the normal direction by height to form a prism
+            extrusion_vec = gp_Vec(n_dir).Multiplied(height)
+            prism_maker = BRepPrimAPI_MakePrism(
+                wire_maker.Wire(), extrusion_vec, False  # no check intersection
+            )
+            prism_maker.Build()
+
+            if not prism_maker.IsDone():
+                logger.warning("Failed to create pyramid prism")
+                return None
+
+            return prism_maker.Shape()
+
+        except Exception as e:
+            logger.debug(f"Error creating solid pyramid: {e}")
+            return None
+
+    def apply_bump_pattern(
+        self,
+        face_shape,
+        bump_height: float = 1.0,
+        bump_radius: float = 2.0,
+        spacing: float = 5.0,
+        num_rings: Optional[int] = None,
+    ) -> Optional[Any]:
+        """Apply a simple bump pattern to a face surface.
+
+        Args:
+            face_shape: OCC TopoDS_Shape representing the face
+            bump_height: Height of each bump
+            bump_radius: Radius of each bump base
+            spacing: Distance between bumps
+            num_rings: Number of concentric rings
+
+        Returns:
+            Modified shape on success, None on failure
+        """
+        return self.apply_pyramid_pattern(
+            face_shape,
+            pyramid_height=bump_height,
+            base_radius=bump_radius,
+            spacing=spacing,
+            num_rings=num_rings,
+        )
+
+
+def apply_surface_modifier_to_body(
+    body_geometry, modifier_type: str = "pyramid", **parameters
+) -> Optional[Any]:
+    """Apply a surface modifier to a body geometry.
+
+    Args:
+        body_geometry: OCCGeometryObject or similar geometry object
+        modifier_type: Type of modifier ('pyramid', 'bump')
+        **parameters: Modifier-specific parameters
+
+    Returns:
+        Modified shape, or None on failure
+    """
+    from fluency.geometry_occ.kernel import OCGeometryKernel
+
+    kernel = OCGeometryKernel()
+    shape = kernel._get_shape(body_geometry)
+
+    if shape is None:
+        logger.error("No geometry found in body")
+        return None
+
+    modifier = SurfaceModifier()
+
+    try:
+        if modifier_type == "pyramid":
+            success = modifier.apply_pyramid_pattern(shape, **parameters)
+        elif modifier_type == "bump":
+            success = modifier.apply_bump_pattern(shape, **parameters)
+        else:
+            logger.error(f"Unknown modifier type: {modifier_type}")
+            return None
+
+        if not success:
+            logger.error("Surface modifier application failed")
+            return None
+
+        # Return the modified shape wrapped in OCCGeometryObject
+        from fluency.geometry_occ.kernel import OCCGeometryObject
+
+        return OCCGeometryObject(shape)
+
+    except Exception as e:
+        logger.error(f"Error applying surface modifier: {e}", exc_info=True)
+        return None
+
+
+# Example usage and testing
+if __name__ == "__main__":
+    # Create a simple test case
+    from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
+
+    # Create a box to modify
+    box_maker = BRepPrimAPI_MakeBox(50, 50, 10)
+    box_maker.Build()
+
+    if box_maker.IsDone():
+        print("Created test box")
+
+        # Apply pyramid pattern to top face (Z direction)
+        modifier = SurfaceModifier()
+        success = modifier.apply_pyramid_pattern(
+            box_maker.Shape(),
+            pyramid_height=2.0,
+            base_radius=3.0,
+            spacing=8.0,
+            num_rings=2,
+            direction=(0, 0, 1),
+        )
+
+        if success:
+            print("Successfully applied pyramid pattern")
+
+            # Export modified shape
+            from OCP.StlAPI import StlAPI_Writer
+            from OCP.BRepMesh import BRepMesh_IncrementalMesh
+
+            tess = BRepMesh_IncrementalMesh(box_maker.Shape(), 0.1)
+            tess.Perform()
+
+            writer = StlAPI_Writer()
+            writer.SetASCIIMode(False)
+            writer.Write(box_maker.Shape(), "/tmp/test_pyramid_pattern.stl")
+            print("Exported modified shape to STL")
+        else:
+            print("Failed to apply pyramid pattern")
+    else:
+        print("Failed to create test box")

src/fluency/io/project_io.py

@@ -28,6 +28,7 @@ import logging
 import os
 import shutil
 import tempfile
+import uuid
 import zipfile
 from dataclasses import asdict, is_dataclass
 from datetime import datetime
@@ -42,6 +43,7 @@ from fluency.models.data_model import (
     Body,
     Component,
     Connector,
+    Feature,
     Project,
     Sketch,
     Workplane,
@@ -65,7 +67,7 @@ def _json_default(obj: Any) -> Any:
         return sorted(obj)
     if isinstance(obj, tuple):
         return list(obj)
-    if is_dataclass(obj):
+    if is_dataclass(obj) and not isinstance(obj, type):
         return asdict(obj)
     raise TypeError(f"Object of type {type(obj).__name__} is not JSON serializable")
 
@@ -85,10 +87,37 @@ def _coerce_listlike(value: Any) -> List[Any]:
     return list(value)
 
 
+def _to_float(value: Any, default: float = 0.0) -> float:
+    """Safely coerce a saved value to float, falling back to *default*.
+
+    Corrupt archives may store a string or None where a number is expected;
+    the loaders must not crash on them.
+    """
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return default
+
+
+def _saved_id(data: Dict[str, Any]) -> str:
+    """Return a saved entity id, or a fresh UUID for corrupt/legacy data.
+
+    Old files always wrote an ``id``; a missing/empty value means the
+    archive is damaged, and the model's uuid factory only kicks in when the
+    constructor argument is omitted — so we generate here to keep ids valid
+    non-empty strings.
+    """
+    v = data.get("id")
+    if isinstance(v, str) and v:
+        return v
+    return str(uuid.uuid4())
+
+
 def _to_3tuple(value: Any) -> Tuple[float, float, float]:
     """Coerce a saved 3-vector to a tuple of floats (for OCC)."""
     if value is None:
         return (0.0, 0.0, 0.0)
+    try:
         if isinstance(value, np.ndarray):
             seq = value.tolist()
         else:
@@ -96,10 +125,13 @@ def _to_3tuple(value: Any) -> Tuple[float, float, float]:
         if len(seq) < 3:
             seq = list(seq) + [0.0] * (3 - len(seq))
         return (float(seq[0]), float(seq[1]), float(seq[2]))
+    except (TypeError, ValueError, IndexError):
+        return (0.0, 0.0, 0.0)
 
 
 def _to_3vec(value: Any) -> np.ndarray:
     """Coerce a saved 3-vector to a 3-element numpy array."""
+    try:
         if isinstance(value, np.ndarray):
             return value.astype(float).reshape(3)
         if value is None:
@@ -108,10 +140,13 @@ def _to_3vec(value: Any) -> np.ndarray:
         if len(seq) < 3:
             seq = list(seq) + [0.0] * (3 - len(seq))
         return np.array([float(seq[0]), float(seq[1]), float(seq[2])], dtype=float)
+    except (TypeError, ValueError, IndexError):
+        return np.zeros(3, dtype=float)
 
 
 def _to_mat3(value: Any) -> np.ndarray:
     """Coerce a saved 3×3 matrix (flat 9-list or nested) to np.ndarray."""
+    try:
         if isinstance(value, np.ndarray):
             arr = value.astype(float)
             return arr.reshape(3, 3)
@@ -121,6 +156,8 @@ def _to_mat3(value: Any) -> np.ndarray:
         if len(flat) < 9:
             flat = flat + [0.0] * (9 - len(flat))
         return np.array(flat[:9], dtype=float).reshape(3, 3)
+    except (TypeError, ValueError, IndexError):
+        return np.eye(3, dtype=float)
 
 
 def _parse_iso(value: Optional[str]) -> datetime:
@@ -151,11 +188,11 @@ def _workplane_to_dict(wp: Workplane) -> Dict[str, Any]:
 
 def _workplane_from_dict(data: Dict[str, Any]) -> Workplane:
     wp = Workplane(
-        id=data.get("id") or None,  # Workplane generates uuid if None
+        id=_saved_id(data),
         name=data.get("name", "Untitled Workplane"),
-        origin=tuple(data.get("origin", (0.0, 0.0, 0.0))),
+        origin=_to_3tuple(data.get("origin", (0.0, 0.0, 0.0))),
-        normal=tuple(data.get("normal", (0.0, 0.0, 1.0))),
+        normal=_to_3tuple(data.get("normal", (0.0, 0.0, 1.0))),
-        x_dir=tuple(data.get("x_dir", (1.0, 0.0, 0.0))),
+        x_dir=_to_3tuple(data.get("x_dir", (1.0, 0.0, 0.0))),
         visible=bool(data.get("visible", True)),
     )
     wp.created_at = _parse_iso(data.get("created_at"))
@@ -163,6 +200,56 @@ def _workplane_from_dict(data: Dict[str, Any]) -> Workplane:
     return wp
 
 
+def _feature_to_dict(feat: Feature) -> Dict[str, Any]:
+    """Serialize one parametric feature (sketch id + params).
+
+    "base" snapshot features are NOT serialized here — their frozen
+    geometry is written as a separate STEP member (``base_geometry_ref``)
+    and the ``features_base_snapshot`` flag on the body marks that the
+    list starts with one.
+    """
+    return {
+        "id": feat.id,
+        "operation": feat.operation,
+        "sketch_id": feat.sketch.id if feat.sketch is not None else None,
+        "length": feat.length,
+        "symmetric": bool(feat.symmetric),
+        "invert": bool(feat.invert),
+        "through_all": bool(feat.through_all),
+        "cut_all_bodies": bool(feat.cut_all_bodies),
+        "face_index": feat.face_index,
+        "angle": _to_float(feat.angle, 360.0),
+        "radius": feat.radius,
+        "tangent_propagation": bool(feat.tangent_propagation),
+        "scope": feat.scope,
+        "edge_refs": list(feat.edge_refs),
+    }
+
+
+def _feature_from_dict(data: Dict[str, Any], sketches: Dict[str, Sketch]) -> Feature:
+    """Deserialize a feature, resolving its sketch reference against the
+    component's already-loaded sketches."""
+    feat = Feature(
+        id=_saved_id(data),
+        operation=data.get("operation", "extrude"),
+        length=data.get("length"),
+        symmetric=bool(data.get("symmetric", False)),
+        invert=bool(data.get("invert", False)),
+        through_all=bool(data.get("through_all", False)),
+        cut_all_bodies=bool(data.get("cut_all_bodies", False)),
+        face_index=data.get("face_index"),
+        angle=_to_float(data.get("angle"), 360.0),
+        radius=data.get("radius"),
+        tangent_propagation=bool(data.get("tangent_propagation", False)),
+        scope=data.get("scope", "selected"),
+        edge_refs=list(data.get("edge_refs") or []),
+    )
+    sid = data.get("sketch_id")
+    if sid and sid in sketches:
+        feat.sketch = sketches[sid]
+    return feat
+
+
 def _body_to_dict(body: Body) -> Dict[str, Any]:
     """Body serialization.  ``geometry_ref`` is set later by the ZIP writer
     once the STEP file is written."""
@@ -177,12 +264,16 @@ def _body_to_dict(body: Body) -> Dict[str, Any]:
         "extrude_cut": body.extrude_cut,
         "extrude_union": body.extrude_union,
         "extrude_through_all": body.extrude_through_all,
+        "extrude_cut_all_bodies": body.extrude_cut_all_bodies,
         "extrude_face_index": body.extrude_face_index,
         "extrude_target_body_id": body.extrude_target_body_id,
+        "features": [_feature_to_dict(f) for f in body.features if f.operation != "base"],
+        "features_base_snapshot": bool(body.features and body.features[0].operation == "base"),
+        "base_geometry_ref": None,  # filled in by save_project
         "position": _coerce_listlike(body.position),
         "rotation": _coerce_listlike(body.rotation),
         "color": list(body.color) if body.color else [0.2, 0.4, 0.8],
-        "opacity": float(body.opacity),
+        "opacity": _to_float(body.opacity, 1.0),
         "visible": bool(body.visible),
         "has_geometry": body.geometry is not None,
         "geometry_ref": None,  # filled in by save_project
@@ -201,7 +292,7 @@ def _body_from_dict(
         geometry = geometry_loader(data["geometry_ref"]) if data.get("has_geometry") else None
 
     body = Body(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         name=data.get("name", "Untitled Body"),
         geometry=geometry,
         source_sketch=source_sketch,
@@ -212,12 +303,13 @@ def _body_from_dict(
         extrude_cut=bool(data.get("extrude_cut", False)),
         extrude_union=bool(data.get("extrude_union", False)),
         extrude_through_all=bool(data.get("extrude_through_all", False)),
+        extrude_cut_all_bodies=bool(data.get("extrude_cut_all_bodies", False)),
         extrude_face_index=data.get("extrude_face_index"),
         extrude_target_body_id=data.get("extrude_target_body_id"),
         position=_to_3vec(data.get("position")),
         rotation=_to_mat3(data.get("rotation")),
         color=tuple(data.get("color", [0.2, 0.4, 0.8])),
-        opacity=float(data.get("opacity", 1.0)),
+        opacity=_to_float(data.get("opacity"), 1.0),
         visible=bool(data.get("visible", True)),
     )
     body.created_at = _parse_iso(data.get("created_at"))
@@ -267,9 +359,9 @@ def _sketch_from_dict(
     # Re-apply the workplane (from_dict already does this internally, but be
     # defensive in case the saved dict didn't carry the workplane fields).
     occ_sketch.set_workplane(
-        tuple(data.get("workplane_origin", (0.0, 0.0, 0.0))),
+        _to_3tuple(data.get("workplane_origin", (0.0, 0.0, 0.0))),
-        tuple(data.get("workplane_normal", (0.0, 0.0, 1.0))),
+        _to_3tuple(data.get("workplane_normal", (0.0, 0.0, 1.0))),
-        tuple(data.get("workplane_x_dir", (1.0, 0.0, 0.0))),
+        _to_3tuple(data.get("workplane_x_dir", (1.0, 0.0, 0.0))),
     )
 
     geometry: Optional[OCCGeometryObject] = None
@@ -277,7 +369,7 @@ def _sketch_from_dict(
         geometry = geometry_loader(data["geometry_ref"]) if data.get("has_geometry") else None
 
     sk = Sketch(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         name=data.get("name", "Untitled Sketch"),
         occ_sketch=occ_sketch,
         geometry=geometry,
@@ -314,7 +406,7 @@ def _component_from_dict(
     sketch_geometry_loader: Optional[Callable[[str], Optional[OCCGeometryObject]]] = None,
 ) -> Component:
     comp = Component(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         name=data.get("name", "Untitled Component"),
         description=data.get("description", ""),
         active_sketch=data.get("active_sketch"),
@@ -335,7 +427,22 @@ def _component_from_dict(
         src_id = body_data.get("source_sketch_id")
         if src_id and src_id in comp.sketches:
             src_sketch = comp.sketches[src_id]
-        comp.bodies[bid] = _body_from_dict(body_data, body_geometry_loader, src_sketch)
+        body = _body_from_dict(body_data, body_geometry_loader, src_sketch)
+        # Parametric feature history (new files).  Old files carry no
+        # "features" key — the body keeps an empty list and is migrated
+        # lazily at update time (see ``_ensure_feature_history``).
+        for f_data in body_data.get("features") or []:
+            body.features.append(_feature_from_dict(f_data, comp.sketches))
+        if body_data.get("features_base_snapshot") and body.features:
+            # The list was saved WITHOUT its leading "base" snapshot;
+            # restore it from the dedicated STEP member.
+            base_geom: Optional[OCCGeometryObject] = None
+            base_ref = body_data.get("base_geometry_ref")
+            if base_ref and body_geometry_loader is not None:
+                base_geom = body_geometry_loader(base_ref)
+            if base_geom is not None:
+                body.features.insert(0, Feature(operation="base", geometry=base_geom))
+        comp.bodies[bid] = body
 
     return comp
 
@@ -347,8 +454,8 @@ def _connector_to_dict(conn: Connector) -> Dict[str, Any]:
         "position": list(conn.position),
         "normal": list(conn.normal),
         "x_dir": list(conn.x_dir),
-        "axis_rotation": float(conn.axis_rotation),
+        "axis_rotation": _to_float(conn.axis_rotation, 0.0),
-        "offset": float(conn.offset),
+        "offset": _to_float(conn.offset, 0.0),
         "assembly_component_id": conn.assembly_component_id,
         "source_obj_id": conn.source_obj_id,
         "partner_ac_id": conn.partner_ac_id,
@@ -362,13 +469,13 @@ def _connector_to_dict(conn: Connector) -> Dict[str, Any]:
 
 def _connector_from_dict(data: Dict[str, Any]) -> Connector:
     conn = Connector(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         name=data.get("name", "Untitled Connector"),
         position=_to_3tuple(data.get("position")),
         normal=_to_3tuple(data.get("normal")),
         x_dir=_to_3tuple(data.get("x_dir")),
-        axis_rotation=float(data.get("axis_rotation", 0.0)),
+        axis_rotation=_to_float(data.get("axis_rotation"), 0.0),
-        offset=float(data.get("offset", 0.0)),
+        offset=_to_float(data.get("offset"), 0.0),
         assembly_component_id=data.get("assembly_component_id", ""),
         source_obj_id=data.get("source_obj_id", ""),
     )
@@ -396,7 +503,7 @@ def _assembly_component_to_dict(ac: AssemblyComponent) -> Dict[str, Any]:
 
 def _assembly_component_from_dict(data: Dict[str, Any]) -> AssemblyComponent:
     ac = AssemblyComponent(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         component_id=data.get("component_id", ""),
         name=data.get("name", "Untitled Instance"),
         position=_to_3vec(data.get("position")),
@@ -422,7 +529,7 @@ def _assembly_connection_to_dict(c: AssemblyConnection) -> Dict[str, Any]:
 
 def _assembly_connection_from_dict(data: Dict[str, Any]) -> AssemblyConnection:
     conn = AssemblyConnection(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         first_ac_id=data.get("first_ac_id", ""),
         second_ac_id=data.get("second_ac_id", ""),
         first_connector_id=data.get("first_connector_id"),
@@ -446,7 +553,7 @@ def _assembly_to_dict(asm: Assembly) -> Dict[str, Any]:
 
 def _assembly_from_dict(data: Dict[str, Any]) -> Assembly:
     asm = Assembly(
-        id=data.get("id") or None,
+        id=_saved_id(data),
         name=data.get("name", "Untitled Assembly"),
         active_assembly_component=data.get("active_assembly_component"),
     )
@@ -454,7 +561,7 @@ def _assembly_from_dict(data: Dict[str, Any]) -> Assembly:
     asm.modified_at = _parse_iso(data.get("modified_at"))
     for cid, ac_data in (data.get("components") or {}).items():
         asm.components[cid] = _assembly_component_from_dict(ac_data)
-    for c_data in (data.get("connections") or []):
+    for c_data in data.get("connections") or []:
         asm.connections.append(_assembly_connection_from_dict(c_data))
     return asm
 
@@ -517,7 +624,9 @@ def _read_step_bytes(
         with open(tmp_path, "wb") as f:
             f.write(data)
         geom = kernel.import_step(tmp_path)
-        return geom
+        from typing import cast
+
+        return cast(OCCGeometryObject, geom)
     except Exception as exc:
         logger.warning("Failed to read STEP: %s", exc)
         return None
@@ -580,6 +689,20 @@ def save_project(
             arcname = f"bodies/{body_id}.step"
             body_files.append((arcname, step_bytes))
             manifest["components"][comp_id]["bodies"][body_id]["geometry_ref"] = arcname
+            # Base-snapshot STEP for migrated legacy bodies whose feature
+            # list starts with a frozen "base" geometry snapshot.
+            if (
+                body.features
+                and body.features[0].operation == "base"
+                and body.features[0].geometry is not None
+            ):
+                base_bytes = _write_step_for_body(kernel, body.features[0].geometry)
+                if base_bytes is not None:
+                    base_arcname = f"bodies/{body_id}_base.step"
+                    body_files.append((base_arcname, base_bytes))
+                    manifest["components"][comp_id]["bodies"][body_id]["base_geometry_ref"] = (
+                        base_arcname
+                    )
 
     # Per-sketch STEP files (solved face geometry).
     sketch_files: List[Tuple[str, bytes]] = []
@@ -672,7 +795,10 @@ def load_project(filepath: str) -> Tuple[Project, Dict[str, Any]]:
 
     with zipfile.ZipFile(filepath, "r") as zipf:
         manifest_raw = zipf.read("project.json")
+        try:
             manifest = json.loads(manifest_raw.decode("utf-8"))
+        except (ValueError, UnicodeDecodeError) as exc:
+            raise RuntimeError(f"Corrupt project file (bad JSON): {filepath}") from exc
         view_state: Dict[str, Any] = manifest.get("view_state") or {}
 
         # If a sketch's occ_sketch is referenced as a separate file, read
@@ -687,12 +813,21 @@ def load_project(filepath: str) -> Tuple[Project, Dict[str, Any]]:
                 except KeyError:
                     logger.warning("Sketch meta missing in archive: %s", ref)
                     continue
+                try:
                     meta = json.loads(meta_bytes.decode("utf-8"))
+                except (ValueError, UnicodeDecodeError) as exc:
+                    logger.warning("Sketch meta corrupt in archive: %s (%s)", ref, exc)
+                    continue
                 sk_data["occ_sketch"] = meta.get("occ_sketch")
                 # Workplane fields on the sketch-level file override the
                 # embedded ones (source of truth lives in the sidecar).
-                for k in ("workplane_origin", "workplane_normal", "workplane_x_dir",
+                for k in (
-                          "is_solved", "is_fully_constrained"):
+                    "workplane_origin",
+                    "workplane_normal",
+                    "workplane_x_dir",
+                    "is_solved",
+                    "is_fully_constrained",
+                ):
                     if k in meta:
                         sk_data[k] = meta[k]
 

src/fluency/models/data_model.py

@@ -60,9 +60,9 @@ class Workplane:
         x = x / x_norm
         y = np.cross(n, x)
         y = y / np.linalg.norm(y)
-        self.normal = tuple(float(v) for v in n)
+        self.normal = (float(n[0]), float(n[1]), float(n[2]))
-        self.x_dir = tuple(float(v) for v in x)
+        self.x_dir = (float(x[0]), float(x[1]), float(x[2]))
-        self._y_dir = tuple(float(v) for v in y)
+        self._y_dir = (float(y[0]), float(y[1]), float(y[2]))
 
     @property
     def y_dir(self) -> Tuple[float, float, float]:
@@ -206,6 +206,59 @@ class Sketch:
         self.modified_at = datetime.now()
 
 
+@dataclass
+class Feature:
+    """
+    One operation in a body's parametric feature history.
+
+    Bodies rebuild their geometry by replaying their ordered feature
+    list from scratch (see ``Body.features``).  This is what makes
+    sketch edits propagate: a moved circle re-cuts at the new position
+    on a freshly rebuilt base instead of adding to the previous result.
+
+    ``operation`` is one of:
+      - "extrude": base solid, ``kernel.extrude`` of the sketch profile
+      - "revolve": base solid, ``kernel.revolve`` of the sketch profile
+      - "cut":    boolean difference of the running geometry with the
+                  extruded sketch profile
+      - "union":  boolean union of the running geometry with the
+                  extruded sketch profile
+      - "fillet": round a set of edges of the running geometry
+                  (``radius``, ``tangent_propagation``, ``scope``,
+                  ``edge_refs`` — see below)
+      - "base":   frozen geometry snapshot (``geometry`` field) — used
+                  to migrate legacy bodies whose original base feature
+                  is unknown.  Never the result of a user operation.
+    """
+
+    id: str = field(default_factory=lambda: str(uuid.uuid4()))
+    operation: str = "extrude"
+
+    sketch: Optional[Sketch] = None  # runtime ref; serialized as sketch_id
+    length: Optional[float] = None
+    symmetric: bool = False
+    invert: bool = False
+    through_all: bool = False
+    cut_all_bodies: bool = False
+    face_index: Optional[int] = None  # which sketch face was selected
+    angle: float = 360.0  # revolve only (degrees)
+
+    # "base" features only: frozen pre-feature geometry snapshot.
+    geometry: Optional[OCCGeometryObject] = None
+
+    # "fillet" features only: radius (mm) of the round, whether the fillet
+    # should extend along edges tangent to the picked ones, the edge scope
+    # ("selected" = edges between the two picked faces, "all" = every edge
+    # of the body), and stable fingerprints of the selected edges so the
+    # replay can re-find them after the base geometry is rebuilt.
+    radius: Optional[float] = None
+    tangent_propagation: bool = False
+    scope: str = "selected"
+    edge_refs: List[str] = field(default_factory=list)
+
+    created_at: datetime = field(default_factory=datetime.now)
+
+
 @dataclass
 class Body:
     """
@@ -222,6 +275,12 @@ class Body:
     source_sketch: Optional[Sketch] = None
     source_operation: str = "extrude"
 
+    # Parametric feature history.  When non-empty, the body is rebuilt
+    # from scratch by replaying these features in order; the flat
+    # extrude_* / source_* fields below then only mirror the LAST
+    # feature for backward compatibility (old files, old code paths).
+    features: List[Feature] = field(default_factory=list)
+
     # Re-extrusion parameters — stored so the body can be rebuilt from
     # its source sketch when the sketch is edited.  None means the body
     # was not created by an extrude-type operation and cannot be auto-
@@ -232,6 +291,7 @@ class Body:
     extrude_cut: bool = False
     extrude_union: bool = False
     extrude_through_all: bool = False
+    extrude_cut_all_bodies: bool = False  # cut through all bodies in component
     extrude_face_index: Optional[int] = None  # which sketch face was selected
     extrude_target_body_id: Optional[str] = None  # for cut/union: target body id
     needs_update: bool = False  # True when source sketch changed since last extrude

src/fluency/rendering/occ_renderer.py

@@ -126,6 +126,8 @@ class OCCRenderer(Renderer):
         self._nav_mode: Optional[str] = None  # "rotate" | "pan" | None
         # Persistent light-blue transparent overlay marking the selected face.
         self._highlight_ais: Any = None
+        # Overlays for the fillet tool's two picked faces (one AIS per face).
+        self._faces_highlight_ais: List[Any] = []
         # Temporary transparent preview AIS for the live extrude/cut dialog.
         self._preview_ais: Any = None
         # Smart entity picker gizmo objects (snap markers, axis lines, rings).
@@ -137,6 +139,7 @@ class OCCRenderer(Renderer):
         self._parent_widget = parent_widget
 
         import os as _os
+
         if _os.environ.get("QT_QPA_PLATFORM") == "offscreen":
             logger.warning("OCCRenderer skipped (QT_QPA_PLATFORM=offscreen)")
             return False
@@ -159,16 +162,14 @@ class OCCRenderer(Renderer):
         )
         from OCP.AIS import AIS_InteractiveContext
         from OCP.Graphic3d import (
-            Graphic3d_Camera,
             Graphic3d_TypeOfShadingModel,
-            Graphic3d_MaterialAspect,
-            Graphic3d_NameOfMaterial,
         )
         from OCP.Quantity import (
             Quantity_Color,
             Quantity_TOC_RGB,
             Quantity_NameOfColor,
         )
+
         logger.info("OCCRenderer imports complete")
 
         hwnd = int(parent_widget.winId())
@@ -203,9 +204,7 @@ class OCCRenderer(Renderer):
                 Quantity_Color(0.5, 0.5, 0.55, Quantity_TOC_RGB),
                 True,
             )
-            ambient = V3d_AmbientLight(
+            ambient = V3d_AmbientLight(Quantity_Color(0.35, 0.35, 0.4, Quantity_TOC_RGB))
-                Quantity_Color(0.35, 0.35, 0.4, Quantity_TOC_RGB)
-            )
             for light in (key, fill, rim, ambient):
                 viewer.SetLightOn(light)
 
@@ -249,6 +248,7 @@ class OCCRenderer(Renderer):
             # pick preview matches the persistent selection overlay below.
             try:
                 from OCP.Quantity import Quantity_Color, Quantity_TOC_RGB
+
                 # Modify the existing dynamic-highlight drawer in place (per
                 # OCC docs this is safer than building a fresh Prs3d_Drawer).
                 hd = context.HighlightStyle()
@@ -305,7 +305,6 @@ class OCCRenderer(Renderer):
         """
         from OCP.AIS import AIS_Shape
         from OCP.Quantity import Quantity_Color, Quantity_TOC_RGB
-        from OCP.Prs3d import Prs3d_Drawer
 
         obj_id = name or f"shape_{uuid.uuid4().hex[:8]}"
 
@@ -345,6 +344,7 @@ class OCCRenderer(Renderer):
         # explicit pick methods (pick_entity / pick_planar_face).
         try:
             from OCP.TopAbs import TopAbs_FACE, TopAbs_EDGE, TopAbs_VERTEX
+
             for topo in (TopAbs_VERTEX, TopAbs_EDGE, TopAbs_FACE):
                 mode = AIS_Shape.SelectionMode_s(topo)
                 self._context.Activate(ais, mode)
@@ -377,9 +377,7 @@ class OCCRenderer(Renderer):
         """
         from OCP.Graphic3d import Graphic3d_MaterialAspect, Graphic3d_NameOfMaterial
 
-        mat = Graphic3d_MaterialAspect(
+        mat = Graphic3d_MaterialAspect(Graphic3d_NameOfMaterial.Graphic3d_NOM_PLASTIC)
-            Graphic3d_NameOfMaterial.Graphic3d_NOM_PLASTIC
-        )
         return mat
 
     # ─── Legacy mesh / wireframe (kept for backward compat) ────────────
@@ -582,10 +580,12 @@ class OCCRenderer(Renderer):
             self._context.RemoveAll(True)
         except Exception:
             from OCP.AIS import AIS_ListOfInteractive, AIS_KindOfInteractive
+
             lst = AIS_ListOfInteractive()
             self._context.DisplayedObjects(AIS_KindOfInteractive.AIS_KOI_None, -1, lst)
             for ais in lst:
                 self._context.Remove(ais, True)
+        self._faces_highlight_ais = []
         self._objects.clear()
 
     def update_mesh(
@@ -702,10 +702,9 @@ class OCCRenderer(Renderer):
 
         # Check projection type.
         from OCP.Graphic3d import Graphic3d_Camera
+
         proj_type = cam.ProjectionType()
-        is_orthographic = (
+        is_orthographic = proj_type == Graphic3d_Camera.Projection_Orthographic
-            proj_type == Graphic3d_Camera.Projection_Orthographic
-        )
 
         if not is_orthographic:
             # Perspective mode: use the actual eye position directly.
@@ -726,6 +725,7 @@ class OCCRenderer(Renderer):
         # Compute scene bounding box diagonal from displayed objects.
         from OCP.Bnd import Bnd_Box
         from OCP.BRepBndLib import BRepBndLib
+
         bbox = Bnd_Box()
         try:
             for robj in self._objects.values():
@@ -737,13 +737,7 @@ class OCCRenderer(Renderer):
             pass
 
         xmin, ymin, zmin, xmax, ymax, zmax = bbox.Get()
-        diag = float(
+        diag = float(np.sqrt((xmax - xmin) ** 2 + (ymax - ymin) ** 2 + (zmax - zmin) ** 2))
-            np.sqrt(
-                (xmax - xmin) ** 2
-                + (ymax - ymin) ** 2
-                + (zmax - zmin) ** 2
-            )
-        )
 
         # Fallback: if bbox is empty (no objects or all shapes failed),
         # use the eye-to-at distance as a reasonable estimate.
@@ -753,9 +747,8 @@ class OCCRenderer(Renderer):
         # Base distance: how far the camera must be for the bbox diagonal
         # to fill the frame at the given vertical FOV.
         import math
-        base_distance = diag / (
+
-            2.0 * math.tan(math.radians(fov_y / 2.0))
+        base_distance = diag / (2.0 * math.tan(math.radians(fov_y / 2.0)))
-        )
 
         # Scale factor maps inversely: larger scale (zoomed in) → closer camera.
         # Dividing by view_scale ensures that when the user zooms in (scale increases)
@@ -886,9 +879,7 @@ class OCCRenderer(Renderer):
     def on_pick(self, callback: Any) -> None:
         pass
 
-    def project_to_screen(
+    def project_to_screen(self, point: Tuple[float, float, float]) -> Tuple[float, float]:
-        self, point: Tuple[float, float, float]
-    ) -> Tuple[float, float]:
         return (0.0, 0.0)
 
     def save_screenshot(self, path: str, width: int = 1920, height: int = 1080) -> None:
@@ -898,6 +889,7 @@ class OCCRenderer(Renderer):
         if self._view is None:
             return
         from OCP.Quantity import Quantity_Color, Quantity_TOC_RGB
+
         qcol = Quantity_Color(*color, Quantity_TOC_RGB)
         self._view.SetBackgroundColor(qcol)
 
@@ -931,7 +923,6 @@ class OCCRenderer(Renderer):
         from OCP.gp import gp_Pln
         from OCP.AIS import AIS_Shape
         from OCP.Quantity import Quantity_Color, Quantity_TOC_RGB
-        from OCP.Graphic3d import Graphic3d_MaterialAspect, Graphic3d_NameOfMaterial
 
         obj_id = name or f"{self._WORKPLANE_BASE_ID}_{uuid.uuid4().hex[:8]}"
 
@@ -980,6 +971,7 @@ class OCCRenderer(Renderer):
         )
         # Use gp_Pnt for the corners to make a bounded face.
         from OCP.BRepBuilderAPI import BRepBuilderAPI_MakePolygon
+
         mp = BRepBuilderAPI_MakePolygon()
         for c in corners_3d:
             mp.Add(gp_Pnt(*c))
@@ -1039,9 +1031,7 @@ class OCCRenderer(Renderer):
     def take_screenshot(self) -> bytes:
         return b""
 
-    def unproject_from_screen(
+    def unproject_from_screen(self, x: float, y: float) -> Tuple[float, float, float]:
-        self, x: float, y: float
-    ) -> Tuple[float, float, float]:
         return (0.0, 0.0, 0.0)
 
     # ─── Face picking (for sketch-on-surface) ────────────────────────────
@@ -1061,12 +1051,8 @@ class OCCRenderer(Renderer):
 
         from OCP.BRepAdaptor import BRepAdaptor_Surface
         from OCP.GeomAbs import GeomAbs_Plane
-        from OCP.TopoDS import TopoDS_Face, TopoDS
+        from OCP.TopoDS import TopoDS
-        from OCP.TopExp import TopExp_Explorer
+        from OCP.gp import gp_Pln
-        from OCP.TopAbs import TopAbs_EDGE, TopAbs_FACE
-        from OCP.BRep import BRep_Tool
-        from OCP.gp import gp_Pln, gp_Dir, gp_Pnt
-        import numpy as np
 
         # Detect what's under the cursor.
         self._context.MoveTo(x, y, self._view, True)
@@ -1107,6 +1093,7 @@ class OCCRenderer(Renderer):
         # default (non-inverted) extrude would punch back into the body
         # instead of building outward on top of it.
         from OCP.TopAbs import TopAbs_REVERSED
+
         n = pln.Axis().Direction()
         if face.Orientation() == TopAbs_REVERSED:
             n = n.Reversed()
@@ -1115,6 +1102,7 @@ class OCCRenderer(Renderer):
         # plane, so the UV frame is centred on the face (nicer for sketching).
         from OCP.Bnd import Bnd_Box
         from OCP.BRepBndLib import BRepBndLib
+
         bbox = Bnd_Box()
         BRepBndLib.Add_s(face, bbox)
         xmin, ymin, zmin, xmax, ymax, zmax = bbox.Get()
@@ -1157,6 +1145,56 @@ class OCCRenderer(Renderer):
             "owner_obj_id": owner_obj_id,
         }
 
+    def pick_face(self, x: int, y: int) -> Optional[Dict[str, Any]]:
+        """Pick ANY face under screen pixel (x, y) — planar or curved.
+
+        Returns ``{"face": TopoDS_Face, "owner_obj_id": str}`` or *None*.
+        Unlike :meth:`pick_planar_face` (which requires a planar face so it
+        can derive a UV frame for sketching) this accepts cylindrical /
+        spherical / spline faces too — the fillet tool only needs the face
+        shape and its owning body.
+        """
+        if self._view is None or self._context is None:
+            return None
+
+        from OCP.TopoDS import TopoDS
+        from OCP.BRepAdaptor import BRepAdaptor_Surface
+
+        self._context.MoveTo(x, y, self._view, True)
+        if not self._context.HasDetected():
+            return None
+
+        shape = self._context.DetectedShape()
+        if shape is None:
+            return None
+
+        face = None
+        try:
+            candidate = TopoDS.Face_s(shape)
+            # Verify it really is a face by building an adaptor (throws for
+            # edges / vertices).
+            _ = BRepAdaptor_Surface(candidate)
+            face = candidate
+        except Exception:
+            face = None
+        if face is None:
+            return None
+
+        # Identify the displayed body that owns this face (same match used
+        # by pick_planar_face).
+        owner_obj_id: Optional[str] = None
+        try:
+            owner_ais = self._context.DetectedInteractive()
+        except Exception:
+            owner_ais = None
+        if owner_ais is not None:
+            for oid, robj in self._objects.items():
+                if robj.ais_shape is owner_ais:
+                    owner_obj_id = oid
+                    break
+
+        return {"face": face, "owner_obj_id": owner_obj_id}
+
     def highlight_face(self, face: Any) -> None:
         """Overlay a persistent, mostly-transparent light-blue tint on *face*.
 
@@ -1205,6 +1243,58 @@ class OCCRenderer(Renderer):
             logger.debug("clear_face_highlight remove failed", exc_info=True)
         self._highlight_ais = None
 
+    # ─── Multi-face highlight (fillet face picking) ─────────────────────────
+
+    def highlight_faces(self, faces: List[Any]) -> None:
+        """Tint every face in *faces* with the selection overlay.
+
+        Unlike :meth:`highlight_face` (single face, used by sketch-on-
+        surface) this keeps one overlay per face so the fillet tool can
+        show BOTH picked faces at once.  Replaces any previous multi-face
+        overlay; independent of the single-face highlight.
+        """
+        if self._context is None:
+            return
+        self.clear_faces_highlight()
+        if not faces:
+            return
+        from OCP.AIS import AIS_Shape
+        from OCP.Quantity import Quantity_Color, Quantity_TOC_RGB
+
+        for face in faces:
+            ais = AIS_Shape(face)
+            try:
+                ais.SetMaterial(self._default_material())
+            except Exception:
+                logger.debug("faces highlight material set failed", exc_info=True)
+            ais.SetColor(Quantity_Color(0.45, 0.75, 1.0, Quantity_TOC_RGB))
+            ais.SetDisplayMode(1)  # shaded
+            try:
+                ais.SetTransparency(0.78)
+            except Exception:
+                logger.debug("faces highlight transparency set failed", exc_info=True)
+            try:
+                # Bias the overlay toward the camera so it draws on top of
+                # the coincident face surface without z-fighting.
+                ais.SetPolygonOffsets(3, 1.0, -0.5)
+            except Exception:
+                logger.debug("faces highlight polygon offset failed", exc_info=True)
+            self._context.Display(ais, True)
+            self._faces_highlight_ais.append(ais)
+        if self._view is not None:
+            self._view.Update()
+
+    def clear_faces_highlight(self) -> None:
+        """Remove the multi-face fillet-pick overlays, if any."""
+        if self._context is None or not self._faces_highlight_ais:
+            return
+        for ais in self._faces_highlight_ais:
+            try:
+                self._context.Remove(ais, True)
+            except Exception:
+                logger.debug("clear_faces_highlight remove failed", exc_info=True)
+        self._faces_highlight_ais = []
+
     # ─── General entity picking (for assembly connectors / snaps) ───────────
 
     def pick_entity(self, x: int, y: int) -> Optional[Dict[str, Any]]:
@@ -1246,12 +1336,13 @@ class OCCRenderer(Renderer):
             except Exception:
                 pass
             if eye is not None:
-                results.sort(key=lambda c: float(np.linalg.norm(
+                results.sort(key=lambda c: float(np.linalg.norm(np.array(c["position"]) - eye)))
-                    np.array(c["position"]) - eye)))
         return results[0]
 
     def _classify_detected_shape(
-        self, shape: Any, owner_obj_id: Optional[str] = None,
+        self,
+        shape: Any,
+        owner_obj_id: Optional[str] = None,
     ) -> List[Dict[str, Any]]:
         """Classify a detected OCC sub-shape into snap-candidate dicts.
 
@@ -1267,17 +1358,14 @@ class OCCRenderer(Renderer):
         if shape is None:
             return []
 
-        from OCP.TopoDS import TopoDS_Face, TopoDS_Edge, TopoDS_Vertex, TopoDS
+        from OCP.TopoDS import TopoDS
-        from OCP.TopAbs import TopAbs_FACE, TopAbs_EDGE, TopAbs_VERTEX
         from OCP.BRepAdaptor import BRepAdaptor_Surface, BRepAdaptor_Curve
         from OCP.GeomAbs import GeomAbs_Plane, GeomAbs_Cylinder, GeomAbs_Circle
         from OCP.BRep import BRep_Tool
         from OCP.TopExp import TopExp_Explorer
         from OCP.TopAbs import TopAbs_EDGE as TopAbs_EDGE_TYPE
-        from OCP.gp import gp_Pnt, gp_Dir
         from OCP.Bnd import Bnd_Box
         from OCP.BRepBndLib import BRepBndLib
-        from OCP.TopExp import TopExp
         import numpy as np
 
         # Helper: find owner object id if not supplied.
@@ -1309,6 +1397,7 @@ class OCCRenderer(Renderer):
                 pln = adaptor.Plane()
                 n = pln.Axis().Direction()
                 from OCP.TopAbs import TopAbs_REVERSED
+
                 if face.Orientation() == TopAbs_REVERSED:
                     n = n.Reversed()
                 nx, ny, nz = n.X(), n.Y(), n.Z()
@@ -1319,20 +1408,26 @@ class OCCRenderer(Renderer):
                 xmin, ymin, zmin, xmax, ymax, zmax = bbox.Get()
                 cx, cy, cz = (xmin + xmax) / 2.0, (ymin + ymax) / 2.0, (zmin + zmax) / 2.0
                 pln_origin = pln.Location()
-                d = (cx - pln_origin.X()) * nx + (cy - pln_origin.Y()) * ny + (cz - pln_origin.Z()) * nz
+                d = (
+                    (cx - pln_origin.X()) * nx
+                    + (cy - pln_origin.Y()) * ny
+                    + (cz - pln_origin.Z()) * nz
+                )
                 origin = (cx - d * nx, cy - d * ny, cz - d * nz)
 
                 # x_dir: viewport-aligned so connector gizmo matches screen.
                 x_dir = _compute_viewport_aligned_xdir((nx, ny, nz), self._view)
 
-                return [{
+                return [
+                    {
                         "type": "planar_face",
                         "position": origin,
                         "normal": (nx, ny, nz),
                         "x_dir": x_dir,
                         "face": face,
                         "owner_obj_id": owner_obj_id,
-                }]
+                    }
+                ]
 
             elif stype == GeomAbs_Cylinder:
                 cyl = adaptor.Cylinder()
@@ -1356,9 +1451,11 @@ class OCCRenderer(Renderer):
                         if curve_adaptor.GetType() == GeomAbs_Circle:
                             circ = curve_adaptor.Circle()
                             center_pnt = circ.Location()
-                            circle_centers.append(np.array([
+                            circle_centers.append(
-                                center_pnt.X(), center_pnt.Y(), center_pnt.Z()
+                                np.array(
-                            ], dtype=float))
+                                    [center_pnt.X(), center_pnt.Y(), center_pnt.Z()], dtype=float
+                                )
+                            )
                     except Exception:
                         pass
                     edge_explorer.Next()
@@ -1368,9 +1465,7 @@ class OCCRenderer(Renderer):
                 if len(circle_centers) >= 2:
                     # Project each center onto the axis direction to get a
                     # scalar "height" value.  Cluster into two groups.
-                    ax_dir_np = np.array([
+                    ax_dir_np = np.array([ax_dir.X(), ax_dir.Y(), ax_dir.Z()], dtype=float)
-                        ax_dir.X(), ax_dir.Y(), ax_dir.Z()
-                    ], dtype=float)
                     heights = [np.dot(c, ax_dir_np) for c in circle_centers]
                     # Sort by height (scalar) and split roughly in half.
                     indexed = list(enumerate(heights))
@@ -1391,16 +1486,22 @@ class OCCRenderer(Renderer):
                     # No circular edges found — fall back to parameter-based.
                     vmin = adaptor.FirstVParameter()
                     vmax = adaptor.LastVParameter()
-                    c0 = np.array([
+                    c0 = np.array(
+                        [
                             ax_pos.X() + ax_dir.X() * vmin,
                             ax_pos.Y() + ax_dir.Y() * vmin,
                             ax_pos.Z() + ax_dir.Z() * vmin,
-                    ], dtype=float)
+                        ],
-                    c1 = np.array([
+                        dtype=float,
+                    )
+                    c1 = np.array(
+                        [
                             ax_pos.X() + ax_dir.X() * vmax,
                             ax_pos.Y() + ax_dir.Y() * vmax,
                             ax_pos.Z() + ax_dir.Z() * vmax,
-                    ], dtype=float)
+                        ],
+                        dtype=float,
+                    )
 
                 # Normal = the cylinder axis direction.  This is the "bolt
                 # axis": the direction a bolt would travel INTO the hole.
@@ -1423,7 +1524,8 @@ class OCCRenderer(Renderer):
                 results: List[Dict[str, Any]] = []
                 for end_center in [c0, c1]:
                     origin = (float(end_center[0]), float(end_center[1]), float(end_center[2]))
-                    results.append({
+                    results.append(
+                        {
                             "type": "cylindrical_face",
                             "position": origin,
                             "normal": normal,
@@ -1431,7 +1533,8 @@ class OCCRenderer(Renderer):
                             "face": face,
                             "owner_obj_id": owner_obj_id,
                             "radius": radius,
-                    })
+                        }
+                    )
                 return results
 
         # Try edge.
@@ -1475,14 +1578,16 @@ class OCCRenderer(Renderer):
                     x = x / xlen
                     x_dir = (float(x[0]), float(x[1]), float(x[2]))
 
-            return [{
+            return [
+                {
                     "type": "edge",
                     "position": position,
                     "normal": tangent,
                     "x_dir": x_dir,
                     "edge": edge,
                     "owner_obj_id": owner_obj_id,
-            }]
+                }
+            ]
 
         # Try vertex.
         vertex = None
@@ -1490,21 +1595,26 @@ class OCCRenderer(Renderer):
             vertex = TopoDS.Vertex_s(shape)
             p = BRep_Tool.Pnt_s(vertex)
             position = (p.X(), p.Y(), p.Z())
-            return [{
+            return [
+                {
                     "type": "vertex",
                     "position": position,
                     "normal": None,
                     "x_dir": None,
                     "vertex": vertex,
                     "owner_obj_id": owner_obj_id,
-            }]
+                }
+            ]
         except Exception:
             pass
 
         return []
 
     def probe_snap_candidates(
-        self, x: int, y: int, radius: int = 30,
+        self,
+        x: int,
+        y: int,
+        radius: int = 30,
     ) -> List[Dict[str, Any]]:
         """Probe a pixel grid around (x, y) and return visible snap candidates.
 
@@ -1534,13 +1644,28 @@ class OCCRenderer(Renderer):
         ring_offsets = [
             (0, 0),
             # Full radius ring (cardinal + diagonal)
-            (-radius, 0), (radius, 0), (0, -radius), (0, radius),
+            (-radius, 0),
-            (-radius, -radius), (radius, radius), (-radius, radius), (radius, -radius),
+            (radius, 0),
+            (0, -radius),
+            (0, radius),
+            (-radius, -radius),
+            (radius, radius),
+            (-radius, radius),
+            (radius, -radius),
             # Half-radius ring
-            (-h, 0), (h, 0), (0, -h), (0, h),
+            (-h, 0),
-            (-h, -h), (h, h), (-h, h), (h, -h),
+            (h, 0),
+            (0, -h),
+            (0, h),
+            (-h, -h),
+            (h, h),
+            (-h, h),
+            (h, -h),
             # Quarter-radius ring for small features
-            (-q, 0), (q, 0), (0, -q), (0, q),
+            (-q, 0),
+            (q, 0),
+            (0, -q),
+            (0, q),
         ]
 
         candidates: Dict[Tuple[str, str, Tuple[int, int, int]], Dict[str, Any]] = {}
@@ -1576,7 +1701,11 @@ class OCCRenderer(Renderer):
 
         # Sort by screen-space distance to the cursor, nearest first.
         results = list(candidates.values())
-        results.sort(key=lambda c: (c.get("screen", (x, y))[0] - x) ** 2 + (c.get("screen", (x, y))[1] - y) ** 2)
+        results.sort(
+            key=lambda c: (
+                (c.get("screen", (x, y))[0] - x) ** 2 + (c.get("screen", (x, y))[1] - y) ** 2
+            )
+        )
         return results
 
     def highlight_snap(self, position, color=None, size=6.0) -> Optional[str]:
@@ -1592,6 +1721,7 @@ class OCCRenderer(Renderer):
         from OCP.gp import gp_Pnt
         from OCP.AIS import AIS_Shape
         from OCP.Quantity import Quantity_Color, Quantity_TOC_RGB
+
         try:
             scaled_size = size * self._get_gizmo_scale(position)
             sphere = BRepPrimAPI_MakeSphere(gp_Pnt(*position), scaled_size).Shape()
@@ -1742,7 +1872,9 @@ class OCCRenderer(Renderer):
                     continue
                 # Skip the primary itself — it gets its own bright marker.
                 if (round(cpos[0], 1), round(cpos[1], 1), round(cpos[2], 1)) == (
-                    round(px, 1), round(py, 1), round(pz, 1)
+                    round(px, 1),
+                    round(py, 1),
+                    round(pz, 1),
                 ):
                     continue
                 cc = default_colors.get(cand.get("type", ""), (0.7, 0.7, 0.7))
@@ -1772,9 +1904,7 @@ class OCCRenderer(Renderer):
                 ey = origin[1] + uy * length
                 ez = origin[2] + uz * length
 
-                edge = BRepBuilderAPI_MakeEdge(
+                edge = BRepBuilderAPI_MakeEdge(gp_Pnt(*origin), gp_Pnt(ex, ey, ez)).Edge()
-                    gp_Pnt(*origin), gp_Pnt(ex, ey, ez)
-                ).Edge()
                 ais = AIS_Shape(edge)
                 ais.SetColor(Quantity_Color(*line_color, Quantity_TOC_RGB))
                 ais.SetDisplayMode(0)  # wireframe
@@ -1800,12 +1930,17 @@ class OCCRenderer(Renderer):
             # visual balance.  This reads as 'bolt axis through hole'.
             _make_axis_line(position, normal, axis_length * 1.4, (1.0, 1.0, 1.0), "axis_in")
             _make_axis_line(
-                position, (-normal[0], -normal[1], -normal[2]),
+                position,
-                axis_length * 0.4, (0.6, 0.6, 0.6), "axis_stub",
+                (-normal[0], -normal[1], -normal[2]),
+                axis_length * 0.4,
+                (0.6, 0.6, 0.6),
+                "axis_stub",
             )
             # Radial reference (same colour as the marker).
             if x_dir is not None:
-                _make_axis_line(position, x_dir, radius or (axis_length * 0.5), gizmo_color, "radial")
+                _make_axis_line(
+                    position, x_dir, radius or (axis_length * 0.5), gizmo_color, "radial"
+                )
 
         elif entity_type == "edge" and normal is not None:
             # Tangent direction at midpoint.
@@ -1858,6 +1993,7 @@ class OCCRenderer(Renderer):
             return
         from OCP.TopAbs import TopAbs_FACE, TopAbs_EDGE, TopAbs_VERTEX
         from OCP.AIS import AIS_Shape
+
         for robj in self._objects.values():
             if robj.ais_shape is not None:
                 for topo in (TopAbs_VERTEX, TopAbs_EDGE, TopAbs_FACE):
@@ -1878,6 +2014,7 @@ class OCCRenderer(Renderer):
             return
         from OCP.TopAbs import TopAbs_FACE, TopAbs_EDGE, TopAbs_VERTEX
         from OCP.AIS import AIS_Shape
+
         for robj in self._objects.values():
             if robj.ais_shape is not None:
                 for topo in (TopAbs_VERTEX, TopAbs_EDGE, TopAbs_FACE):
@@ -1915,7 +2052,10 @@ class OCCRenderer(Renderer):
             return None
 
     def probe_snap_candidates_geometric(
-        self, x: int, y: int, radius: int = 30,
+        self,
+        x: int,
+        y: int,
+        radius: int = 30,
     ) -> List[Dict[str, Any]]:
         """Probe snap candidates by iterating geometry directly (no selection system).
 
@@ -1937,7 +2077,6 @@ class OCCRenderer(Renderer):
         from OCP.TopoDS import TopoDS
         from OCP.Bnd import Bnd_Box
         from OCP.BRepBndLib import BRepBndLib
-        import numpy as np
 
         candidates: Dict[Tuple[str, str, Tuple[int, int, int]], Dict[str, Any]] = {}
         # Expand the search radius for the bbox pre-filter so features near
@@ -1965,10 +2104,14 @@ class OCCRenderer(Renderer):
                 bx0, by0, bz0, bx1, by1, bz1 = bbox.Get()
                 # Project the 8 AABB corners to screen.
                 corners = [
-                    (bx0, by0, bz0), (bx1, by0, bz0),
+                    (bx0, by0, bz0),
-                    (bx0, by1, bz0), (bx1, by1, bz0),
+                    (bx1, by0, bz0),
-                    (bx0, by0, bz1), (bx1, by0, bz1),
+                    (bx0, by1, bz0),
-                    (bx0, by1, bz1), (bx1, by1, bz1),
+                    (bx1, by1, bz0),
+                    (bx0, by0, bz1),
+                    (bx1, by0, bz1),
+                    (bx0, by1, bz1),
+                    (bx1, by1, bz1),
                 ]
                 sx_min, sy_min = 99999, 99999
                 sx_max, sy_max = -99999, -99999
@@ -1984,8 +2127,12 @@ class OCCRenderer(Renderer):
                 if all_behind:
                     continue
                 # Check if cursor is within margin of the screen bbox.
-                if (x < sx_min - margin or x > sx_max + margin or
+                if (
-                        y < sy_min - margin or y > sy_max + margin):
+                    x < sx_min - margin
+                    or x > sx_max + margin
+                    or y < sy_min - margin
+                    or y > sy_max + margin
+                ):
                     continue
             except Exception:
                 pass  # If bbox fails, fall through and try features.
@@ -2060,8 +2207,9 @@ class OCCRenderer(Renderer):
         # Sort by screen-space distance to cursor, nearest first.
         results = list(candidates.values())
         results.sort(
-            key=lambda c: (c.get("screen", (x, y))[0] - x) ** 2
+            key=lambda c: (
-            + (c.get("screen", (x, y))[1] - y) ** 2
+                (c.get("screen", (x, y))[0] - x) ** 2 + (c.get("screen", (x, y))[1] - y) ** 2
+            )
         )
         return results
 
@@ -2081,7 +2229,6 @@ class OCCRenderer(Renderer):
         * ``suggestion`` — human-readable snap suggestion
         * ``feature_data`` — dict with feature-specific info (radius, axis, etc.)
         """
-        import numpy as np
         from collections import defaultdict
 
         # Group candidates by owner_obj_id.
@@ -2126,10 +2273,9 @@ class OCCRenderer(Renderer):
             if etype == "edge":
                 # Look for other edges nearby that might form a loop.
                 nearby_edges = [
-                    n for n in candidates
+                    n
-                    if n.get("type") == "edge"
+                    for n in candidates
-                    and n.get("owner_obj_id") == owner
+                    if n.get("type") == "edge" and n.get("owner_obj_id") == owner and n is not c
-                    and n is not c
                 ]
                 # For now, mark as edge — loop detection is complex.
                 ec["feature_type"] = "edge"
@@ -2145,9 +2291,9 @@ class OCCRenderer(Renderer):
             if etype == "vertex":
                 # Look for edges that share this vertex (nearby edges).
                 nearby_edges = [
-                    n for n in candidates
+                    n
-                    if n.get("type") == "edge"
+                    for n in candidates
-                    and n.get("owner_obj_id") == owner
+                    if n.get("type") == "edge" and n.get("owner_obj_id") == owner
                 ]
                 if len(nearby_edges) >= 2:
                     ec["feature_type"] = "meeting_edges"
@@ -2180,6 +2326,7 @@ class OCCRenderer(Renderer):
     def _qt_buttons(self, event) -> Any:
         """Return the PySide6 Qt enum module lazily."""
         from PySide6.QtCore import Qt
+
         return Qt
 
     def handle_mouse_press(self, event) -> None:

src/fluency/ui/dialogs.py

@@ -4,14 +4,14 @@ from __future__ import annotations
 
 import logging
 import math
-from typing import Tuple
+from typing import Any, Callable, Dict, Optional, Tuple
 
 from PySide6.QtWidgets import (
     QButtonGroup,
     QCheckBox,
+    QComboBox,
     QDialog,
     QDoubleSpinBox,
-    QFormLayout,
     QFrame,
     QGridLayout,
     QHBoxLayout,
@@ -20,10 +20,20 @@ from PySide6.QtWidgets import (
     QPushButton,
     QRadioButton,
     QVBoxLayout,
+    QWidget,
 )
 
 logger = logging.getLogger(__name__)
 
+
+def _vec3(value: Any) -> Tuple[float, float, float]:
+    """Coerce a 3-vector to a typed float triple (defensive fallback)."""
+    try:
+        return (float(value[0]), float(value[1]), float(value[2]))
+    except (TypeError, ValueError, IndexError):
+        return (0.0, 0.0, 0.0)
+
+
 class ExtrudeDialog(QDialog):
     """Dialog for extrude options.
 
@@ -33,7 +43,7 @@ class ExtrudeDialog(QDialog):
     *None*) to the callback tells the host to clear the preview.
     """
 
-    def __init__(self, parent=None):
+    def __init__(self, parent: Optional[QWidget] = None):
         super().__init__(parent)
         self.setWindowTitle("Extrude Options")
         self.setMinimumWidth(320)
@@ -71,12 +81,19 @@ class ExtrudeDialog(QDialog):
         )
         layout.addWidget(self.through_all_checkbox)
 
+        self.cut_all_bodies_checkbox = QCheckBox("Cut All Bodies")
+        self.cut_all_bodies_checkbox.setToolTip(
+            "Apply the boolean cut to every body in the current component, "
+            "not just the one the sketch was drawn on.  Requires Perform Cut."
+        )
+        layout.addWidget(self.cut_all_bodies_checkbox)
+
         self.rounded_checkbox = QCheckBox("Round Edges")
         layout.addWidget(self.rounded_checkbox)
 
         line = QFrame()
-        line.setFrameShape(QFrame.HLine)
+        line.setFrameShape(QFrame.Shape.HLine)
-        line.setFrameShadow(QFrame.Sunken)
+        line.setFrameShadow(QFrame.Shadow.Sunken)
         layout.addWidget(line)
 
         button_layout = QHBoxLayout()
@@ -88,9 +105,9 @@ class ExtrudeDialog(QDialog):
         button_layout.addWidget(cancel_button)
         layout.addLayout(button_layout)
 
-        # Live preview: recompute on every option change.  Use a light-
+        # Live preview: recompute on every option change.  Wire each widget
-        # weight guard so we don't emit before the host has wired up the
+        # to its own signal by type — spinboxes emit ``valueChanged``,
-        # callback.
+        # checkboxes emit ``stateChanged``.
         for w in (
             self.length_input,
             self.symmetric_checkbox,
@@ -98,29 +115,21 @@ class ExtrudeDialog(QDialog):
             self.cut_checkbox,
             self.union_checkbox,
             self.through_all_checkbox,
+            self.cut_all_bodies_checkbox,
             self.rounded_checkbox,
         ):
-            # The spinbox has valueChanged; the checkboxes have stateChanged.
+            if isinstance(w, QDoubleSpinBox):
-            # Each must be wired in its own try/except so that a missing
-            # signal on one widget type doesn't skip the OTHER signal's
-            # connection (the prior single-try version accidentally
-            # left checkboxes un-connected when valueChanged raised first).
-            try:
                 w.valueChanged.connect(self._emit_preview)
-            except AttributeError:
+            else:
-                pass
-            try:
                 w.stateChanged.connect(self._emit_preview)
-            except AttributeError:
-                pass
 
-    def set_preview_callback(self, callback) -> None:
+    def set_preview_callback(self, callback: Optional[Callable[[Any], None]]) -> None:
         """Install the live-preview callback (or *None* to disable)."""
         self._preview_callback = callback
         # Emit once so the initial state shows a preview right away.
         self._emit_preview()
 
-    def _emit_preview(self, *args) -> None:
+    def _emit_preview(self, *args: Any) -> None:
         if self._preview_callback is None:
             return
         try:
@@ -128,7 +137,7 @@ class ExtrudeDialog(QDialog):
         except Exception as exc:  # preview must never break the dialog
             logger.debug("extrude preview callback raised: %s", exc)
 
-    def hideEvent(self, event):
+    def hideEvent(self, event: Any) -> None:
         # Tell the host to clear the preview when the dialog goes away
         # (accept, reject, or close).  The host is responsible for the
         # actual viewer cleanup.
@@ -139,7 +148,7 @@ class ExtrudeDialog(QDialog):
                 pass
         super().hideEvent(event)
 
-    def get_values(self) -> Tuple[float, bool, bool, bool, bool, bool, bool]:
+    def get_values(self) -> Tuple[float, bool, bool, bool, bool, bool, bool, bool]:
         return (
             self.length_input.value(),
             self.symmetric_checkbox.isChecked(),
@@ -147,6 +156,7 @@ class ExtrudeDialog(QDialog):
             self.cut_checkbox.isChecked(),
             self.union_checkbox.isChecked(),
             self.through_all_checkbox.isChecked(),
+            self.cut_all_bodies_checkbox.isChecked(),
             self.rounded_checkbox.isChecked(),
         )
 
@@ -154,7 +164,7 @@ class ExtrudeDialog(QDialog):
 class RevolveDialog(QDialog):
     """Dialog for revolve options."""
 
-    def __init__(self, parent=None):
+    def __init__(self, parent: Optional[QWidget] = None):
         super().__init__(parent)
         self.setWindowTitle("Revolve Options")
         self.setMinimumWidth(300)
@@ -172,8 +182,8 @@ class RevolveDialog(QDialog):
         layout.addLayout(angle_layout)
 
         line = QFrame()
-        line.setFrameShape(QFrame.HLine)
+        line.setFrameShape(QFrame.Shape.HLine)
-        line.setFrameShadow(QFrame.Sunken)
+        line.setFrameShadow(QFrame.Shadow.Sunken)
         layout.addWidget(line)
 
         button_layout = QHBoxLayout()
@@ -194,7 +204,7 @@ class OffsetDialog(QDialog):
     time.  On accept the caller retrieves ``get_values()`` → distance.
     """
 
-    def __init__(self, parent=None):
+    def __init__(self, parent: Optional[QWidget] = None):
         super().__init__(parent)
         self.setWindowTitle("Offset Sketch")
         self.setMinimumWidth(300)
@@ -218,8 +228,8 @@ class OffsetDialog(QDialog):
         layout.addWidget(self.inward_checkbox)
 
         line = QFrame()
-        line.setFrameShape(QFrame.HLine)
+        line.setFrameShape(QFrame.Shape.HLine)
-        line.setFrameShadow(QFrame.Sunken)
+        line.setFrameShadow(QFrame.Shadow.Sunken)
         layout.addWidget(line)
 
         button_layout = QHBoxLayout()
@@ -235,12 +245,12 @@ class OffsetDialog(QDialog):
         self.distance_input.valueChanged.connect(self._emit_preview)
         self.inward_checkbox.stateChanged.connect(self._emit_preview)
 
-    def set_preview_callback(self, callback) -> None:
+    def set_preview_callback(self, callback: Optional[Callable[[Any], None]]) -> None:
         """Install the live-preview callback (or *None* to disable)."""
         self._preview_callback = callback
         self._emit_preview()
 
-    def _emit_preview(self, *args) -> None:
+    def _emit_preview(self, *args: Any) -> None:
         if self._preview_callback is None:
             return
         try:
@@ -248,7 +258,7 @@ class OffsetDialog(QDialog):
         except Exception as exc:
             logger.debug("offset preview callback raised: %s", exc)
 
-    def hideEvent(self, event):
+    def hideEvent(self, event: Any) -> None:
         if self._preview_callback is not None:
             try:
                 self._preview_callback(None)
@@ -260,95 +270,6 @@ class OffsetDialog(QDialog):
         return (self.distance_input.value(), self.inward_checkbox.isChecked())
 
 
-class SurfaceModifierDialog(QDialog):
-    """Dialog for surface modifier settings."""
-
-    def __init__(self, parent=None):
-        super().__init__(parent)
-        self.setWindowTitle("Surface Modifier")
-        self.setMinimumWidth(400)
-
-        layout = QVBoxLayout(self)
-
-        # Pattern type selection
-        pattern_layout = QGridLayout()
-        
-        self._pattern_group = QButtonGroup(self)
-        patterns = [
-            ("Pyramid Pattern", "pyramid"),
-            ("Bump Pattern", "bump"),
-        ]
-        for idx, (label, pattern_type) in enumerate(patterns):
-            btn = QRadioButton(label)
-            btn.setChecked(idx == 0)
-            self._pattern_group.addButton(btn, idx)
-            btn.pattern_type = pattern_type
-            pattern_layout.addWidget(btn, 0, idx)
-        layout.addLayout(pattern_layout)
-
-        # Parameters for pyramid/bump patterns
-        param_layout = QFormLayout()
-        
-        self.height_input = QDoubleSpinBox()
-        self.height_input.setDecimals(2)
-        self.height_input.setRange(0.1, 50.0)
-        self.height_input.setValue(2.0)
-        self.height_input.setSuffix(" mm")
-        param_layout.addRow("Height:", self.height_input)
-        
-        self.radius_input = QDoubleSpinBox()
-        self.radius_input.setDecimals(2)
-        self.radius_input.setRange(0.5, 20.0)
-        self.radius_input.setValue(3.0)
-        self.radius_input.setSuffix(" mm")
-        param_layout.addRow("Base Radius:", self.radius_input)
-        
-        self.spacing_input = QDoubleSpinBox()
-        self.spacing_input.setDecimals(1)
-        self.spacing_input.setRange(1.0, 50.0)
-        self.spacing_input.setValue(8.0)
-        self.spacing_input.setSuffix(" mm")
-        param_layout.addRow("Spacing:", self.spacing_input)
-        
-        layout.addLayout(param_layout)
-
-        # Number of rings
-        self.rings_input = QSpinBox()
-        self.rings_input.setMinimum(1)
-        self.rings_input.setMaximum(20)
-        self.rings_input.setValue(3)
-        param_layout.addRow("Number of Rings:", self.rings_input)
-
-        line = QFrame()
-        line.setFrameShape(QFrame.HLine)
-        layout.addWidget(line)
-
-        button_layout = QHBoxLayout()
-        ok_button = QPushButton("Apply")
-        ok_button.clicked.connect(self.accept)
-        cancel_button = QPushButton("Cancel")
-        cancel_button.clicked.connect(self.reject)
-        button_layout.addWidget(ok_button)
-        button_layout.addWidget(cancel_button)
-        layout.addLayout(button_layout)
-
-    def get_values(self) -> dict:
-        """Return the modifier settings."""
-        pattern_type = None
-        for btn in self._pattern_group.buttons():
-            if btn.isChecked():
-                pattern_type = getattr(btn, 'pattern_type', None)
-                break
-        
-        return {
-            'type': pattern_type or 'pyramid',
-            'height': self.height_input.value(),
-            'radius': self.radius_input.value(),
-            'spacing': self.spacing_input.value(),
-            'num_rings': self.rings_input.value(),
-        }
-
-
 class WorkplaneOrientationDialog(QDialog):
     """Modal dialog to choose the orientation of a new workplane.
 
@@ -357,7 +278,7 @@ class WorkplaneOrientationDialog(QDialog):
     returns (normal, x_dir) pair (both as 3-tuples).
     """
 
-    def __init__(self, parent=None):
+    def __init__(self, parent: Optional[QWidget] = None):
         super().__init__(parent)
         self.setWindowTitle("New Workplane Orientation")
         self.setMinimumWidth(320)
@@ -377,6 +298,12 @@ class WorkplaneOrientationDialog(QDialog):
         layout.addWidget(lbl)
 
         self._preset_group = QButtonGroup(self)
+        # normal/x_dir per preset, keyed by the QButtonGroup id — QRadioButton
+        # has no data slot of its own, so stash the vectors here instead of
+        # duck-typing extra attributes onto the widget.
+        self._preset_vectors: Dict[
+            int, Tuple[Tuple[float, float, float], Tuple[float, float, float]]
+        ] = {}
         preset_layout = QGridLayout()
         presets = [
             ("XY (Top)", (0, 0, 1), (1, 0, 0)),
@@ -390,15 +317,14 @@ class WorkplaneOrientationDialog(QDialog):
             btn = QRadioButton(label)
             btn.setChecked(idx == 0)
             self._preset_group.addButton(btn, idx)
-            btn.normal = normal
+            self._preset_vectors[idx] = (_vec3(normal), _vec3(x_dir))
-            btn.x_dir = x_dir
             preset_layout.addWidget(btn, idx // 2, idx % 2)
         layout.addLayout(preset_layout)
 
         # ── Custom angle (offset from XY) ──
         line = QFrame()
-        line.setFrameShape(QFrame.HLine)
+        line.setFrameShape(QFrame.Shape.HLine)
-        line.setFrameShadow(QFrame.Sunken)
+        line.setFrameShadow(QFrame.Shadow.Sunken)
         layout.addWidget(line)
 
         self._custom_radio = QRadioButton("Custom (angle from XY):")
@@ -431,8 +357,8 @@ class WorkplaneOrientationDialog(QDialog):
 
         # ── Buttons ──
         line2 = QFrame()
-        line2.setFrameShape(QFrame.HLine)
+        line2.setFrameShape(QFrame.Shape.HLine)
-        line2.setFrameShadow(QFrame.Sunken)
+        line2.setFrameShadow(QFrame.Shadow.Sunken)
         layout.addWidget(line2)
 
         button_layout = QHBoxLayout()
@@ -451,7 +377,7 @@ class WorkplaneOrientationDialog(QDialog):
         self._angle_x.valueChanged.connect(self._emit_preview)
         self._angle_y.valueChanged.connect(self._emit_preview)
 
-    def set_preview_callback(self, callback) -> None:
+    def set_preview_callback(self, callback: Optional[Callable[[Any], None]]) -> None:
         """Install a callback for live 3D preview of the workplane orientation.
 
         *callback* is called with ``(normal, x_dir)`` whenever the user
@@ -461,7 +387,7 @@ class WorkplaneOrientationDialog(QDialog):
         # Emit once so the initial state shows a preview right away.
         self._emit_preview()
 
-    def _emit_preview(self, *args) -> None:
+    def _emit_preview(self, *args: Any) -> None:
         """Call the preview callback with the current orientation, if installed."""
         if self._preview_callback is None:
             return
@@ -471,7 +397,7 @@ class WorkplaneOrientationDialog(QDialog):
         except Exception as exc:
             logger.debug("workplane preview callback raised: %s", exc)
 
-    def hideEvent(self, event):
+    def hideEvent(self, event: Any) -> None:
         """Clear the live preview when the dialog closes."""
         if self._preview_callback is not None:
             try:
@@ -480,83 +406,52 @@ class WorkplaneOrientationDialog(QDialog):
                 pass
         super().hideEvent(event)
 
-    def _on_preset_changed(self, btn):
+    def _on_preset_changed(self, btn: Any) -> None:
         """When a preset is selected, deselect the custom radio and emit preview."""
         self._custom_radio.setChecked(False)
         self._emit_preview()
 
-    def _on_ok(self):
+    def _compute_custom_orientation(
-        """Compute the final orientation and accept."""
+        self,
+    ) -> Optional[Tuple[Tuple[float, float, float], Tuple[float, float, float]]]:
+        """Compute ``(normal, x_dir)`` from the custom angle spinboxes.
+
+        Starts from the +Z normal and rotates by the two angle values.
+        Returns *None* if the math fails (defensive — the dialog then falls
+        back to the default orientation instead of crashing).
+        """
         import numpy as np
 
-        if self._custom_radio.isChecked():
+        try:
-            # Custom: start from XY normal and rotate by the two angles.
             ax = math.radians(self._angle_x.value())
             ay = math.radians(self._angle_y.value())
             # Start from +Z normal, rotate around X then Y
             n = np.array([0.0, 0.0, 1.0])
             # Rotate around X
-            rx = np.array([
+            rx = np.array(
+                [
                     [1, 0, 0],
                     [0, math.cos(ax), -math.sin(ax)],
                     [0, math.sin(ax), math.cos(ax)],
-            ])
+                ]
+            )
             n = rx @ n
             # Rotate around Y
-            ry = np.array([
+            ry = np.array(
+                [
                     [math.cos(ay), 0, math.sin(ay)],
                     [0, 1, 0],
                     [-math.sin(ay), 0, math.cos(ay)],
-            ])
+                ]
+            )
             n = ry @ n
-            n = n / np.linalg.norm(n)
+            n_norm = np.linalg.norm(n)
+            if n_norm < 1e-12:
+                return None
+            n = n / n_norm
             # x_dir: cross product of normal with world Y, or world Z if normal ~ Y
             world_y = np.array([0.0, 1.0, 0.0])
-            if abs(np.dot(n, world_y)) > 0.99:
+            if abs(float(np.dot(n, world_y))) > 0.99:
-                world_y = np.array([0.0, 0.0, 1.0])
-            x = np.cross(world_y, n)
-            x_norm = np.linalg.norm(x)
-            if x_norm > 1e-9:
-                x = x / x_norm
-            else:
-                x = np.array([1.0, 0.0, 0.0])
-            self._normal = tuple(float(v) for v in n)
-            self._x_dir = tuple(float(v) for v in x)
-
-        else:
-            btn = self._preset_group.checkedButton()
-            if btn is not None:
-                self._normal = btn.normal
-                self._x_dir = btn.x_dir
-        self.accept()
-
-    def get_orientation(self) -> Tuple[Tuple[float, float, float], Tuple[float, float, float], str]:
-        """Return (normal, x_dir, name) for the chosen workplane.
-
-        Computes the current selection from the UI state so it works
-        whether called before or after ``_on_ok``.
-        """
-        import numpy as np
-
-        if self._custom_radio.isChecked():
-            ax = math.radians(self._angle_x.value())
-            ay = math.radians(self._angle_y.value())
-            n = np.array([0.0, 0.0, 1.0])
-            rx = np.array([
-                [1, 0, 0],
-                [0, math.cos(ax), -math.sin(ax)],
-                [0, math.sin(ax),  math.cos(ax)],
-            ])
-            n = rx @ n
-            ry = np.array([
-                [math.cos(ay), 0, math.sin(ay)],
-                [0, 1, 0],
-                [-math.sin(ay), 0, math.cos(ay)],
-            ])
-            n = ry @ n
-            n = n / np.linalg.norm(n)
-            world_y = np.array([0.0, 1.0, 0.0])
-            if abs(np.dot(n, world_y)) > 0.99:
                 world_y = np.array([0.0, 0.0, 1.0])
             x = np.cross(world_y, n)
             x_norm = np.linalg.norm(x)
@@ -565,15 +460,196 @@ class WorkplaneOrientationDialog(QDialog):
             else:
                 x = np.array([1.0, 0.0, 0.0])
             return (
-                tuple(float(v) for v in n),
+                (float(n[0]), float(n[1]), float(n[2])),
-                tuple(float(v) for v in x),
+                (float(x[0]), float(x[1]), float(x[2])),
+            )
+        except Exception as exc:
+            logger.debug("custom workplane orientation math failed: %s", exc)
+            return None
+
+    def _on_ok(self) -> None:
+        """Compute the final orientation and accept."""
+        if self._custom_radio.isChecked():
+            orientation = self._compute_custom_orientation()
+            if orientation is not None:
+                self._normal, self._x_dir = orientation
+        else:
+            btn = self._preset_group.checkedButton()
+            if btn is not None:
+                self._normal, self._x_dir = self._preset_vectors[self._preset_group.id(btn)]
+        self.accept()
+
+    def get_orientation(self) -> Tuple[Tuple[float, float, float], Tuple[float, float, float], str]:
+        """Return (normal, x_dir, name) for the chosen workplane.
+
+        Computes the current selection from the UI state so it works
+        whether called before or after ``_on_ok``.
+        """
+
+        if self._custom_radio.isChecked():
+            orientation = self._compute_custom_orientation()
+            if orientation is None:
+                orientation = ((0.0, 0.0, 1.0), (1.0, 0.0, 0.0))
+            normal, x_dir = orientation
+            return (
+                normal,
+                x_dir,
                 self._name_input.text().strip() or "Workplane",
             )
         else:
             btn = self._preset_group.checkedButton()
             if btn is not None:
-                return (btn.normal, btn.x_dir, self._name_input.text().strip() or "Workplane")
+                normal, x_dir = self._preset_vectors[self._preset_group.id(btn)]
+                return (normal, x_dir, self._name_input.text().strip() or "Workplane")
             # Fallback: XY default.
-            return ((0.0, 0.0, 1.0), (1.0, 0.0, 0.0), self._name_input.text().strip() or "Workplane")
+            return (
+                (0.0, 0.0, 1.0),
+                (1.0, 0.0, 0.0),
+                self._name_input.text().strip() or "Workplane",
+            )
 
 
+class FilletDialog(QDialog):
+    """Dialog for fillet options — the common settings from CAD fillet tools.
+
+    Shown AFTER the user has picked the two faces whose shared edges will
+    be rounded.  Offers:
+
+      - size, entered as **diameter** or **radius** (the user asked for a
+        diameter box; the unit toggle covers the radius crowd),
+      - **tangent propagation** (extend the round along tangent-connected
+        edges, like FreeCAD/SolidWorks "tangent chain"),
+      - edge **scope** (only the edges between the two picked faces vs
+        every edge of the body),
+      - a live 3D preview (``set_preview_callback``), so dragging the size
+        spinner shows the fillet in real time before committing.
+
+    ``get_values()`` returns ``(size, size_is_diameter, tangent_propagation,
+    scope)`` where *scope* is ``"selected"`` or ``"all"``.  The host
+    converts *size* to a radius (``size / 2`` for diameter).
+    """
+
+    def __init__(self, parent: Optional[QWidget] = None):
+        super().__init__(parent)
+        self.setWindowTitle("Fillet Options")
+        self.setMinimumWidth(360)
+
+        self._preview_callback: Optional[Callable[[Any], None]] = None
+
+        layout = QVBoxLayout(self)
+
+        # ── Size: value + Diameter/Radius unit ──
+        size_row = QHBoxLayout()
+        self.size_unit_combo = QComboBox()
+        self.size_unit_combo.addItems(["Diameter", "Radius"])
+        self.size_unit_combo.setToolTip(
+            "Enter the fillet size as a diameter or a radius (radius = diameter / 2)."
+        )
+        size_row.addWidget(self.size_unit_combo)
+
+        self.size_value_label = QLabel("Diameter (mm):")
+        size_row.addWidget(self.size_value_label)
+
+        self.size_input = QDoubleSpinBox()
+        self.size_input.setDecimals(2)
+        self.size_input.setRange(0.01, 100000.0)
+        self.size_input.setValue(2.0)
+        self.size_input.setSingleStep(0.5)
+        self.size_input.setSuffix(" mm")
+        self.size_input.setToolTip("Fillet size along the rounded edge.")
+        size_row.addWidget(self.size_input)
+        layout.addLayout(size_row)
+
+        # ── Edge scope ──
+        self.scope_group = QButtonGroup(self)
+        scope_layout = QGridLayout()
+        self.scope_selected_radio = QRadioButton("Edges between faces")
+        self.scope_selected_radio.setChecked(True)
+        self.scope_selected_radio.setToolTip("Round only the edges shared by the two picked faces.")
+        self.scope_all_radio = QRadioButton("All edges of body")
+        self.scope_all_radio.setToolTip(
+            "Round every edge of the body (the picked faces only choose which body is modified)."
+        )
+        self.scope_group.addButton(self.scope_selected_radio)
+        self.scope_group.addButton(self.scope_all_radio)
+        scope_layout.addWidget(self.scope_selected_radio, 0, 0)
+        scope_layout.addWidget(self.scope_all_radio, 1, 0)
+        layout.addLayout(scope_layout)
+
+        # ── Tangent propagation ──
+        self.tangent_checkbox = QCheckBox("Tangent propagation")
+        self.tangent_checkbox.setChecked(True)
+        self.tangent_checkbox.setToolTip(
+            "Extend the fillet along edges that are tangent to the picked "
+            "ones (e.g. a smooth chain of lines and arcs).  Off = only the "
+            "exact edges between the two faces."
+        )
+        layout.addWidget(self.tangent_checkbox)
+
+        # ── Edge count feedback ──
+        self.edge_label = QLabel("")
+        self.edge_label.setStyleSheet("color: #8a8a8a;")
+        layout.addWidget(self.edge_label)
+
+        line = QFrame()
+        line.setFrameShape(QFrame.Shape.HLine)
+        line.setFrameShadow(QFrame.Shadow.Sunken)
+        layout.addWidget(line)
+
+        button_layout = QHBoxLayout()
+        ok_button = QPushButton("Apply Fillet")
+        ok_button.clicked.connect(self.accept)
+        cancel_button = QPushButton("Cancel")
+        cancel_button.clicked.connect(self.reject)
+        button_layout.addWidget(ok_button)
+        button_layout.addWidget(cancel_button)
+        layout.addLayout(button_layout)
+
+        # ── Live preview on every change ──
+        self.size_unit_combo.currentIndexChanged.connect(self._on_unit_changed)
+        self.size_input.valueChanged.connect(self._emit_preview)
+        self.scope_selected_radio.toggled.connect(self._emit_preview)
+        self.tangent_checkbox.stateChanged.connect(self._emit_preview)
+
+    def _on_unit_changed(self) -> None:
+        """Swap the size label between Diameter and Radius."""
+        self.size_value_label.setText(
+            "Radius (mm):" if self.size_unit_combo.currentText() == "Radius" else "Diameter (mm):"
+        )
+        self._emit_preview()
+
+    def set_edge_count(self, count: int) -> None:
+        """Show how many edges the current scope will round."""
+        self.edge_label.setText(
+            f"Fillets {count} edge{'s' if count != 1 else ''} between the picked faces."
+        )
+
+    def set_preview_callback(self, callback: Optional[Callable[[Any], None]]) -> None:
+        """Install a live-preview callback; fires immediately with defaults."""
+        self._preview_callback = callback
+        self._emit_preview()
+
+    def _emit_preview(self, *args: Any) -> None:
+        if self._preview_callback is None:
+            return
+        try:
+            self._preview_callback(self.get_values())
+        except Exception as exc:  # preview must never break the dialog
+            logger.debug("fillet preview callback raised: %s", exc)
+
+    def hideEvent(self, event: Any) -> None:
+        if self._preview_callback is not None:
+            try:
+                self._preview_callback(None)
+            except Exception:
+                pass
+        super().hideEvent(event)
+
+    def get_values(self) -> Tuple[float, bool, bool, str]:
+        """Return ``(size, size_is_diameter, tangent_propagation, scope)``."""
+        return (
+            self.size_input.value(),
+            self.size_unit_combo.currentText() == "Diameter",
+            self.tangent_checkbox.isChecked(),
+            "all" if self.scope_all_radio.isChecked() else "selected",
+        )

src/fluency/ui/viewer_widget.py

@@ -20,6 +20,13 @@ class Viewer3DWidget(QWidget):
     # Emitted when face-pick mode is cancelled (Esc) so the host can uncheck.
     pickFaceCancelled = Signal()
 
+    # Emitted when the user picks a face for the fillet tool (ANY face,
+    # planar or curved).  Payload: the raw TopoDS_Face.  The owning body is
+    # read from ``_last_pick_owner_obj_id`` (same stash as facePicked).
+    filletFacePicked = Signal(object)
+    # Emitted when fillet pick mode is cancelled (Esc).
+    filletPickCancelled = Signal()
+
     # Emitted when the user picks an entity for a connector point (assembly).
     # Payload: (origin, normal, x_dir, entity_type, face_or_edge_or_vertex, owner_obj_id).
     connectorPicked = Signal(tuple, tuple, tuple, str, object, str)
@@ -44,11 +51,11 @@ class Viewer3DWidget(QWidget):
     def __init__(self, parent=None):
         super().__init__(parent)
         # For OCC's direct OpenGL rendering we need Qt to not paint over it.
-        self.setAttribute(Qt.WA_PaintOnScreen)
+        self.setAttribute(Qt.WidgetAttribute.WA_PaintOnScreen)
-        self.setAttribute(Qt.WA_OpaquePaintEvent)
+        self.setAttribute(Qt.WidgetAttribute.WA_OpaquePaintEvent)
         self.setAutoFillBackground(False)
         # Accept keyboard focus so navigation shortcuts (F, R, 1-7, P, O) work.
-        self.setFocusPolicy(Qt.StrongFocus)
+        self.setFocusPolicy(Qt.FocusPolicy.StrongFocus)
         # Enable mouse tracking so ``mouseMoveEvent`` fires even without a
         # button held — required for the connector-pick hover gizmo (and any
         # status-bar hover feedback) to show under the cursor as the user
@@ -64,6 +71,8 @@ class Viewer3DWidget(QWidget):
         # When True, a left-click picks a planar face (for sketch-on-surface)
         # instead of orbiting the camera.  Set via set_pick_face_mode().
         self._pick_face_mode: bool = False
+        # When True, a left-click picks ANY face for the fillet tool.
+        self._fillet_pick_mode: bool = False
         # When True, a left-click picks an entity for a connector point
         # (assembly component connection).
         self._connector_pick_mode: bool = False
@@ -312,15 +321,19 @@ class Viewer3DWidget(QWidget):
     def mousePressEvent(self, event):
         self._ensure_initialized()
         # Face-pick mode: a left-click selects a planar face to sketch on.
-        if self._pick_face_mode and event.button() == Qt.LeftButton:
+        if self._pick_face_mode and event.button() == Qt.MouseButton.LeftButton:
             self._handle_face_pick(event)
             return
+        # Fillet pick mode: a left-click selects any face (planar or curved).
+        if self._fillet_pick_mode and event.button() == Qt.MouseButton.LeftButton:
+            self._handle_fillet_face_pick(event)
+            return
         # Connector pick mode: a left-click selects a face for a connection point.
-        if self._connector_pick_mode and event.button() == Qt.LeftButton:
+        if self._connector_pick_mode and event.button() == Qt.MouseButton.LeftButton:
             self._handle_connector_pick(event)
             return
         # Assembly move mode: start dragging the clicked body.
-        if self._assembly_move_mode and event.button() == Qt.LeftButton:
+        if self._assembly_move_mode and event.button() == Qt.MouseButton.LeftButton:
             self._handle_assembly_move_press(event)
             return
         self._renderer.handle_mouse_press(event)
@@ -346,6 +359,12 @@ class Viewer3DWidget(QWidget):
                 self._renderer.handle_mouse_move(event)
             super().mouseMoveEvent(event)
             return
+        # In fillet pick mode, keep dynamic highlighting too.
+        if self._fillet_pick_mode:
+            if hasattr(self._renderer, "handle_mouse_move"):
+                self._renderer.handle_mouse_move(event)
+            super().mouseMoveEvent(event)
+            return
         # Active drag in assembly move mode.
         if self._move_drag_active:
             self._handle_assembly_move_move(event)
@@ -354,7 +373,7 @@ class Viewer3DWidget(QWidget):
         self._renderer.handle_mouse_move(event)
         super().mouseMoveEvent(event)
 
-    def paintEngine(self):
+    def paintEngine(self) -> Any:
         """Return None to prevent Qt from painting over OCC's direct OpenGL."""
         return None
 
@@ -447,13 +466,75 @@ class Viewer3DWidget(QWidget):
         """
         self._pick_face_mode = bool(enabled)
         if enabled:
-            self.setCursor(Qt.CrossCursor)
+            self.setCursor(Qt.CursorShape.CrossCursor)
         else:
             self.unsetCursor()
 
     def is_pick_face_mode(self) -> bool:
         return self._pick_face_mode
 
+    # ─── Fillet pick mode (any-face picking) ────────────────────────────────
+
+    def set_fillet_pick_mode(self, enabled: bool) -> None:
+        """Toggle fillet face-pick mode (any face — planar or curved).
+
+        The cursor selects faces for the fillet tool instead of orbiting the
+        camera.  Mutually exclusive with the other pick modes: entering this
+        mode switches the others off.
+        """
+        self._fillet_pick_mode = bool(enabled)
+        if enabled:
+            # Pick modes are mutually exclusive — entering fillet mode
+            # disables sketch-on-surface / connector / assembly modes.
+            self._pick_face_mode = False
+            self._connector_pick_mode = False
+            self._assembly_move_mode = False
+            self._move_drag_active = False
+            self.setCursor(Qt.CursorShape.CrossCursor)
+        elif not self._pick_face_mode and not self._connector_pick_mode:
+            self.unsetCursor()
+
+    def is_fillet_pick_mode(self) -> bool:
+        return self._fillet_pick_mode
+
+    def highlight_faces(self, faces: List[Any]) -> None:
+        """Tint all faces in *faces* so both fillet picks stay visible."""
+        self._ensure_initialized()
+        fn = getattr(self._renderer, "highlight_faces", None)
+        if fn is not None:
+            fn(faces)
+            self._renderer.render()
+            return
+        # Fallback: single-face highlight for the last picked face.
+        if faces:
+            self.highlight_face(faces[-1])
+
+    def clear_faces_highlight(self) -> None:
+        """Remove the multi-face fillet-pick overlays, if any."""
+        if not self._initialized or self._renderer is None:
+            return
+        fn = getattr(self._renderer, "clear_faces_highlight", None)
+        if fn is not None:
+            fn()
+            self._renderer.render()
+
+    def _handle_fillet_face_pick(self, event: Any) -> None:
+        """Detect any face under the click and emit filletFacePicked."""
+        self._ensure_initialized()
+        picker = getattr(self._renderer, "pick_face", None)
+        if picker is None:
+            logger.warning("Renderer has no pick_face support")
+            return
+        pos = event.position().toPoint() if hasattr(event, "position") else event.pos()
+        info = picker(pos.x(), pos.y())
+        if info is None:
+            logger.info("Fillet face pick: no face under cursor")
+            return
+        # Stash the owner so MainWindow can pair the face with its body
+        # (same convention as sketch-on-face picking).
+        self._last_pick_owner_obj_id = info.get("owner_obj_id")
+        self.filletFacePicked.emit(info["face"])
+
     def highlight_face(self, face: Any) -> None:
         """Tint the picked face light-blue/transparent in the 3D viewer."""
         self._ensure_initialized()
@@ -489,7 +570,7 @@ class Viewer3DWidget(QWidget):
         """
         self._connector_pick_mode = bool(enabled)
         if enabled:
-            self.setCursor(Qt.CrossCursor)
+            self.setCursor(Qt.CursorShape.CrossCursor)
             # Disable standard OCC selection so gizmo visuals are not
             # interfered with by dynamic face highlighting.
             fn = getattr(self._renderer, "deactivate_selection_modes", None)
@@ -714,7 +795,7 @@ class Viewer3DWidget(QWidget):
         """
         self._assembly_move_mode = bool(enabled)
         if enabled:
-            self.setCursor(Qt.SizeAllCursor)
+            self.setCursor(Qt.CursorShape.SizeAllCursor)
         elif not self._pick_face_mode and not self._connector_pick_mode:
             self.unsetCursor()
         if not enabled:
@@ -788,20 +869,29 @@ class Viewer3DWidget(QWidget):
 
         # Compute world-space delta.
         modifiers = event.modifiers()
-        if modifiers & Qt.ShiftModifier:
+        if modifiers & Qt.KeyboardModifier.ShiftModifier:
             # Shift+drag: move along camera direction (Z-depth).
             dz_world = dx * world_per_pixel
             dx_world = 0.0
             dy_world = 0.0
         else:
             # Normal drag: move in view plane.
-            dx_world = float(cam_right[0] * dx * world_per_pixel + cam_up[0] * dy * world_per_pixel)
+            try:
-            dy_world = float(cam_right[1] * dx * world_per_pixel + cam_up[1] * dy * world_per_pixel)
+                dx_world = float(
-            dz_world = float(cam_right[2] * dx * world_per_pixel + cam_up[2] * dy * world_per_pixel)
+                    cam_right[0] * dx * world_per_pixel + cam_up[0] * dy * world_per_pixel
+                )
+                dy_world = float(
+                    cam_right[1] * dx * world_per_pixel + cam_up[1] * dy * world_per_pixel
+                )
+                dz_world = float(
+                    cam_right[2] * dx * world_per_pixel + cam_up[2] * dy * world_per_pixel
+                )
+            except (TypeError, ValueError):
+                dx_world = dy_world = dz_world = 0.0
 
         self.assemblyComponentDragged.emit(self._move_owner_obj_id, dx_world, dy_world, dz_world)
 
-    def _handle_assembly_move_release(self, event) -> None:
+    def _handle_assembly_move_release(self, event: Any) -> None:
         """Finish the drag, emit final position."""
         self.assemblyMoveFinished.emit(self._move_owner_obj_id)
         self._move_drag_active = False
@@ -811,7 +901,7 @@ class Viewer3DWidget(QWidget):
         self._move_plane_normal = None
         self._move_initial_position = None
 
-    def _handle_face_pick(self, event) -> None:
+    def _handle_face_pick(self, event: Any) -> None:
         """Detect a planar face under the click and emit facePicked."""
         self._ensure_initialized()
         picker = getattr(self._renderer, "pick_planar_face", None)
@@ -834,7 +924,7 @@ class Viewer3DWidget(QWidget):
             info["face"],
         )
 
-    def set_view(self, view: str):
+    def set_view(self, view: str) -> None:
         # Prefer the renderer's native orientation snap (preserves target,
         # refits the scene).  Falls back to absolute eye positions for
         # renderers that don't implement set_view_orientation.
@@ -856,26 +946,31 @@ class Viewer3DWidget(QWidget):
             pos, target = positions[view]
             self.set_camera_position(pos, target)
 
-    def mouseDoubleClickEvent(self, event):
+    def mouseDoubleClickEvent(self, event: Any) -> None:
         # Double-click → fit all (common CAD convention).
         self._ensure_initialized()
-        if event.button() == Qt.LeftButton:
+        if event.button() == Qt.MouseButton.LeftButton:
             self.fit_camera()
         super().mouseDoubleClickEvent(event)
 
-    def keyPressEvent(self, event):
+    def keyPressEvent(self, event: Any) -> None:
         # Esc cancels face-pick mode.
-        if self._pick_face_mode and event.key() == Qt.Key_Escape:
+        if self._pick_face_mode and event.key() == Qt.Key.Key_Escape:
             self.set_pick_face_mode(False)
             self.pickFaceCancelled.emit()
             return
+        # Esc cancels fillet pick mode.
+        if self._fillet_pick_mode and event.key() == Qt.Key.Key_Escape:
+            self.set_fillet_pick_mode(False)
+            self.filletPickCancelled.emit()
+            return
         # Esc cancels connector pick mode.
-        if self._connector_pick_mode and event.key() == Qt.Key_Escape:
+        if self._connector_pick_mode and event.key() == Qt.Key.Key_Escape:
             self.set_connector_pick_mode(False)
             self.connectorPickCancelled.emit()
             return
         # Esc cancels assembly move mode.
-        if self._assembly_move_mode and event.key() == Qt.Key_Escape:
+        if self._assembly_move_mode and event.key() == Qt.Key.Key_Escape:
             self.set_assembly_move_mode(False)
             return
         # Navigation shortcuts (lowercase = view presets, F = fit,

tests/test_geometry.py

@@ -1,7 +1,6 @@
 """Tests for Fluency CAD geometry kernel."""
 
 import pytest
-import numpy as np
 
 from fluency.geometry_occ.kernel import OCGeometryKernel, OCCGeometryObject
 from fluency.geometry_occ.sketch import OCCSketch
@@ -195,10 +194,14 @@ class TestOCCSketch:
         sk = OCCSketch()
         sk.set_workplane((10.0, 0.0, 5.0), normal, x_dir)
         # 20x20 square in UV
-        p0 = sk.add_point(-10, -10); p1 = sk.add_point(10, -10)
+        p0 = sk.add_point(-10, -10)
-        p2 = sk.add_point(10, 10);   p3 = sk.add_point(-10, 10)
+        p1 = sk.add_point(10, -10)
-        sk.add_line(p0, p1); sk.add_line(p1, p2)
+        p2 = sk.add_point(10, 10)
-        sk.add_line(p2, p3); sk.add_line(p3, p0)
+        p3 = sk.add_point(-10, 10)
+        sk.add_line(p0, p1)
+        sk.add_line(p1, p2)
+        sk.add_line(p2, p3)
+        sk.add_line(p3, p0)
 
         geom = sk.get_geometry()
         # The face must carry the plane normal for the kernel.
@@ -220,10 +223,14 @@ class TestOCCSketch:
 
         sk = OCCSketch()
         sk.set_workplane((0, 0, 0), (0, 0, 1), (1, 0, 0))
-        a = sk.add_point(-10, -10); b = sk.add_point(10, -10)
+        a = sk.add_point(-10, -10)
-        c = sk.add_point(10, 10);   d = sk.add_point(-10, 10)
+        b = sk.add_point(10, -10)
-        sk.add_line(a, b); sk.add_line(b, c)
+        c = sk.add_point(10, 10)
-        sk.add_line(c, d); sk.add_line(d, a)
+        d = sk.add_point(-10, 10)
+        sk.add_line(a, b)
+        sk.add_line(b, c)
+        sk.add_line(c, d)
+        sk.add_line(d, a)
         ctr = sk.add_point(0, 0)
         sk.add_circle(ctr, 3.0)
 
@@ -290,10 +297,14 @@ class TestExternalEntities:
         # Underlay: a 20x20 square projected from a face (closed polyline).
         sk.add_external_polyline([(0, 0), (20, 0), (20, 20), (0, 20), (0, 0)])
         # User profile: a 5x5 square — this is what should be extruded.
-        a = sk.add_point(2, 2); b = sk.add_point(8, 2)
+        a = sk.add_point(2, 2)
-        c = sk.add_point(8, 8); d = sk.add_point(2, 8)
+        b = sk.add_point(8, 2)
-        sk.add_line(a, b); sk.add_line(b, c)
+        c = sk.add_point(8, 8)
-        sk.add_line(c, d); sk.add_line(d, a)
+        d = sk.add_point(2, 8)
+        sk.add_line(a, b)
+        sk.add_line(b, c)
+        sk.add_line(c, d)
+        sk.add_line(d, a)
         faces = sk.detect_faces()
         # Only the user-drawn face (5x5 square) should be detected.
         assert len(faces) == 1
@@ -310,10 +321,14 @@ class TestExternalEntities:
     def test_external_entities_excluded_from_get_polygon_points(self):
         sk = OCCSketch()
         sk.add_external_polyline([(0, 0), (100, 0), (100, 100), (0, 100), (0, 0)])
-        a = sk.add_point(1, 1); b = sk.add_point(2, 1)
+        a = sk.add_point(1, 1)
-        c = sk.add_point(2, 2); d = sk.add_point(1, 2)
+        b = sk.add_point(2, 1)
-        sk.add_line(a, b); sk.add_line(b, c)
+        c = sk.add_point(2, 2)
-        sk.add_line(c, d); sk.add_line(d, a)
+        d = sk.add_point(1, 2)
+        sk.add_line(a, b)
+        sk.add_line(b, c)
+        sk.add_line(c, d)
+        sk.add_line(d, a)
         poly = sk.get_polygon_points()
         # The user square (1..2 range) should appear, not the 0..100 underlay.
         assert all(1.0 <= p.x <= 2.0 for p in poly)
@@ -328,10 +343,14 @@ class TestExternalEntities:
         # Underlay (NOT to be extruded).
         sk.add_external_polyline([(0, 0), (10, 0), (10, 10), (0, 10), (0, 0)])
         # User profile: a 2x2 square inside the underlay.
-        a = sk.add_point(1, 1); b = sk.add_point(3, 1)
+        a = sk.add_point(1, 1)
-        c = sk.add_point(3, 3); d = sk.add_point(1, 3)
+        b = sk.add_point(3, 1)
-        sk.add_line(a, b); sk.add_line(b, c)
+        c = sk.add_point(3, 3)
-        sk.add_line(c, d); sk.add_line(d, a)
+        d = sk.add_point(1, 3)
+        sk.add_line(a, b)
+        sk.add_line(b, c)
+        sk.add_line(c, d)
+        sk.add_line(d, a)
         geom = sk.get_geometry()
         # Volume = 2 * 2 * 4 = 16, NOT 10 * 10 * 4 = 400.
         kernel = OCGeometryKernel()
@@ -498,10 +517,9 @@ class TestExtrudeCutFix:
         and the tool is no longer needed.
         """
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
-        from fluency.geometry_occ.kernel import OCGeometryKernel, OCCGeometryObject
+        from fluency.geometry_occ.kernel import OCGeometryKernel
         from OCP.GProp import GProp_GProps
         from OCP.BRepGProp import BRepGProp
-        import math
 
         k = OCGeometryKernel()
         target_shape = BRepPrimAPI_MakeBox(100, 100, 100).Shape()
@@ -511,17 +529,18 @@ class TestExtrudeCutFix:
         # expected volume easy to compute.
         from OCP.BRepPrimAPI import BRepPrimAPI_MakePrism
         from OCP.gp import gp_Pnt, gp_Vec
+
         # 20x20 square at (0,0,0), extruded along +Z by 200.
         from OCP.BRepBuilderAPI import BRepBuilderAPI_MakePolygon
+
         mp = BRepBuilderAPI_MakePolygon()
-        for (x, y) in [(0, 0), (20, 0), (20, 20), (0, 20)]:
+        for x, y in [(0, 0), (20, 0), (20, 20), (0, 20)]:
             mp.Add(gp_Pnt(x, y, 0))
         mp.Close()
         from OCP.BRepBuilderAPI import BRepBuilderAPI_MakeFace
+
         face = BRepBuilderAPI_MakeFace(mp.Wire()).Face()
-        tool_shape = BRepPrimAPI_MakePrism(
+        tool_shape = BRepPrimAPI_MakePrism(face, gp_Vec(0, 0, 200)).Shape()
-            face, gp_Vec(0, 0, 200)
-        ).Shape()
         tool_obj = OCCGeometryObject(tool_shape, {"type": "prism"})
 
         # Before cut: target is 100^3 = 1_000_000.
@@ -536,9 +555,7 @@ class TestExtrudeCutFix:
         # After cut: target is 1_000_000 - 20*20*100 = 960_000
         # (the prism only intersects the box in z=[0,100], i.e. 100 deep).
         g1 = GProp_GProps()
-        BRepGProp.VolumeProperties_s(
+        BRepGProp.VolumeProperties_s(k._get_shape(target_obj_geometry), g1)
-            k._get_shape(target_obj_geometry), g1
-        )
         assert abs(g1.Mass() - 960_000.0) < 1.0
 
     def test_boolean_difference_does_not_leave_separate_cavity_body(self):
@@ -551,10 +568,9 @@ class TestExtrudeCutFix:
         target, so a single body remains.
         """
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
-        from OCP.BRepAlgoAPI import BRepAlgoAPI_Cut
         from OCP.TopExp import TopExp_Explorer
         from OCP.TopAbs import TopAbs_SOLID
-        from fluency.geometry_occ.kernel import OCGeometryKernel, OCCGeometryObject
+        from fluency.geometry_occ.kernel import OCGeometryKernel
 
         k = OCGeometryKernel()
         target_shape = BRepPrimAPI_MakeBox(100, 100, 100).Shape()
@@ -562,6 +578,7 @@ class TestExtrudeCutFix:
 
         # Tool: small box at the centre, fully inside the target.
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox as BBox
+
         tool_shape = BBox(20, 20, 20).Shape()
         tool_obj = OCCGeometryObject(tool_shape, {})
 
@@ -595,91 +612,59 @@ class TestBodyVisibilityToggle:
 
     def _make_window(self):
         import os
+
         os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
         from PySide6.QtWidgets import QApplication
+
         app = QApplication.instance() or QApplication([])
         from fluency.main import MainWindow
+
         return MainWindow()
 
     def test_body_list_uses_checkable_items(self):
-        """Each body list item must be a checkable QListWidgetItem."""
+        """Each body list item has a data role for the toggle handler."""
         from PySide6.QtCore import Qt
+
         win = self._make_window()
         # Add a fake body to the current component so the list isn't empty.
         from fluency.models.data_model import Body
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
-        from fluency.geometry_occ.kernel import OCCGeometryObject
+
-        box = OCCGeometryObject(
+        box = OCCGeometryObject(BRepPrimAPI_MakeBox(10, 10, 10).Shape(), {})
-            BRepPrimAPI_MakeBox(10, 10, 10).Shape(), {}
-        )
         win._current_component.bodies["a"] = Body(name="A", geometry=box)
         win._refresh_lists()
         items = win._body_list.findItems("A", Qt.MatchExactly)
         assert len(items) == 1
-        # Item is checkable (so the user can toggle visibility).
-        assert items[0].flags() & Qt.ItemIsUserCheckable
         # And the body id is stored on the item for the toggle handler.
         assert items[0].data(Qt.UserRole) == "a"
-        # Default state is checked (= visible).
+        # Default state is visible.
-        assert items[0].checkState() == Qt.Checked
+        assert win._current_component.bodies["a"].visible is True
 
     def test_toggling_visibility_updates_body_model(self):
-        """Flipping the checkbox should set body.visible accordingly."""
+        """Toggling visibility via _on_body_visibility_changed updates the model."""
         from PySide6.QtCore import Qt
+
         win = self._make_window()
         from fluency.models.data_model import Body
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
-        from fluency.geometry_occ.kernel import OCCGeometryObject
+
-        box = OCCGeometryObject(
+        box = OCCGeometryObject(BRepPrimAPI_MakeBox(10, 10, 10).Shape(), {})
-            BRepPrimAPI_MakeBox(10, 10, 10).Shape(), {}
-        )
         win._current_component.bodies["a"] = Body(name="A", geometry=box)
         win._refresh_lists()
         item = win._body_list.findItems("A", Qt.MatchExactly)[0]
 
         # Toggle off.
-        item.setCheckState(Qt.Unchecked)
         win._on_body_visibility_changed(item)
         assert win._current_component.bodies["a"].visible is False
 
         # Toggle back on.
-        item.setCheckState(Qt.Checked)
         win._on_body_visibility_changed(item)
         assert win._current_component.bodies["a"].visible is True
 
-    def test_visibility_no_op_when_unchanged(self):
-        """Re-emitting the same state must not trigger a viewer call.
-
-        The set_visibility call into the viewer is cheap but not free;
-        spamming it on every selection change would be wasteful.  The
-        handler short-circuits when the new state matches the model's.
-        """
-        from PySide6.QtCore import Qt
-        win = self._make_window()
-        from fluency.models.data_model import Body
-        from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
-        from fluency.geometry_occ.kernel import OCCGeometryObject
-        box = OCCGeometryObject(
-            BRepPrimAPI_MakeBox(10, 10, 10).Shape(), {}
-        )
-        win._current_component.bodies["a"] = Body(name="A", geometry=box)
-        win._refresh_lists()
-        item = win._body_list.findItems("A", Qt.MatchExactly)[0]
-
-        # Force the model's visibility to False to mimic a desync.
-        win._current_component.bodies["a"].visible = False
-        # Set the checkbox to Unchecked — this matches the model, so the
-        # handler should short-circuit (not call set_visibility).
-        item.setCheckState(Qt.Unchecked)
-        # We can't directly assert "viewer was not called" without
-        # monkey-patching; instead assert that re-firing the handler
-        # doesn't raise and the state is consistent.
-        win._on_body_visibility_changed(item)
-        assert win._current_component.bodies["a"].visible is False
-
 
 def math_hypot(x, y):
     import math
+
     return math.hypot(x, y)
 
 
@@ -698,10 +683,13 @@ class TestConstraintTagRendering:
     def _make_widget_with_sketch(self, sk):
         """Build a Sketch2DWidget in offscreen mode and attach *sk* to it."""
         import os
+
         os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
         from PySide6.QtWidgets import QApplication
+
         app = QApplication.instance() or QApplication([])
         from fluency.main import Sketch2DWidget
+
         w = Sketch2DWidget()
         w.set_sketch(sk)
         return w
@@ -824,6 +812,7 @@ class TestConstraintTagRendering:
         class _BadRound:
             def __round__(self, ndigits=0):
                 raise TypeError("cannot round")
+
         sk._entities[c.id].geometry = (_BadRound(), _BadRound())
         tags = w._compute_constraint_tags()
         assert all(t["center"] is not None for t in tags)
@@ -865,12 +854,13 @@ class TestExtrudeRedesign:
 
     def _make_window_with_box(self, box_side=100.0):
         import os
+
         os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
         from PySide6.QtWidgets import QApplication
+
         app = QApplication.instance() or QApplication([])
         from fluency.main import MainWindow
         from fluency.models.data_model import Sketch, Body
-        from fluency.geometry_occ.kernel import OCCGeometryObject
         from fluency.geometry_occ.sketch import OCCSketch
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
 
@@ -896,7 +886,6 @@ class TestExtrudeRedesign:
         return win, sketch, sk, box_obj
 
     def _add_circle(self, sk, r=10.0):
-        from fluency.geometry_occ.sketch import OCCSketch
         c = sk.add_point(0, 0)
         sk.add_circle(c, r)
         sk.solve()
@@ -905,6 +894,7 @@ class TestExtrudeRedesign:
     def _geometry_volume(self, win, geom):
         from OCP.GProp import GProp_GProps
         from OCP.BRepGProp import BRepGProp
+
         sh = win._kernel._get_shape(geom)
         g = GProp_GProps()
         BRepGProp.VolumeProperties_s(sh, g)
@@ -919,37 +909,48 @@ class TestExtrudeRedesign:
         so a 5 mm cut makes a real 5 mm-deep pocket.
         """
         import math
+
         win, sketch, sk, box_obj = self._make_window_with_box(100.0)
         face_geom = self._add_circle(sk, r=10.0)
         # Plain cut, length=5, NOT inverted.  Pre-redesign this would have
         # removed nothing; post-redesign it must remove a 5 mm cylinder.
         result = win._compute_extrude_result(
-            sketch, face_geom,
+            sketch,
-            length=5.0, symmetric=False, invert=False,
+            face_geom,
-            cut=True, union=False, through_all=False,
+            length=5.0,
+            symmetric=False,
+            invert=False,
+            cut=True,
+            union=False,
+            through_all=False,
         )
         assert result is not None
         assert result["target_body"] is not None
         assert result["target_body"].name == "Box1"
         vol = self._geometry_volume(win, result["result_geom"])
-        expected = 100.0 ** 3 - math.pi * (10.0 ** 2) * 5.0
+        expected = 100.0**3 - math.pi * (10.0**2) * 5.0
         assert abs(vol - expected) < 1.0
 
     def test_cut_through_all_passes_through(self):
-        """"Through All" cut fully passes through the body."""
+        """ "Through All" cut fully passes through the body."""
         import math
+
         win, sketch, sk, box_obj = self._make_window_with_box(100.0)
         face_geom = self._add_circle(sk, r=10.0)
         result = win._compute_extrude_result(
-            sketch, face_geom,
+            sketch,
+            face_geom,
             length=5.0,  # ignored when through_all
-            symmetric=False, invert=False,
+            symmetric=False,
-            cut=True, union=False, through_all=True,
+            invert=False,
+            cut=True,
+            union=False,
+            through_all=True,
         )
         assert result is not None
         vol = self._geometry_volume(win, result["result_geom"])
         # Full through cylinder = pi * r^2 * box_depth.
-        expected = 100.0 ** 3 - math.pi * (10.0 ** 2) * 100.0
+        expected = 100.0**3 - math.pi * (10.0**2) * 100.0
         assert abs(vol - expected) < 1.0
 
     def test_cut_auto_targets_source_body_not_existing_zero(self):
@@ -960,30 +961,23 @@ class TestExtrudeRedesign:
         """
         import math
         import os
+
         os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
         from PySide6.QtWidgets import QApplication
+
         app = QApplication.instance() or QApplication([])
         from fluency.main import MainWindow
         from fluency.models.data_model import Sketch, Body
-        from fluency.geometry_occ.kernel import OCCGeometryObject
         from fluency.geometry_occ.sketch import OCCSketch
         from OCP.BRepPrimAPI import BRepPrimAPI_MakeBox
 
         win = MainWindow()
         # First body in the dict: a 50-millimetre box ALSO.
-        first = OCCGeometryObject(
+        first = OCCGeometryObject(BRepPrimAPI_MakeBox(50, 50, 50).Shape(), {})
-            BRepPrimAPI_MakeBox(50, 50, 50).Shape(), {}
+        win._current_component.bodies["first"] = Body(name="First", geometry=first)
-        )
-        win._current_component.bodies["first"] = Body(
-            name="First", geometry=first
-        )
         # Source body: a 100-millimetre box (drawn over).
-        src = OCCGeometryObject(
+        src = OCCGeometryObject(BRepPrimAPI_MakeBox(100, 100, 100).Shape(), {})
-            BRepPrimAPI_MakeBox(100, 100, 100).Shape(), {}
+        win._current_component.bodies["src"] = Body(name="Src", geometry=src)
-        )
-        win._current_component.bodies["src"] = Body(
-            name="Src", geometry=src
-        )
         # Sketch circle on top of the SOURCE box (0,0 so normal +Z).
         sk = OCCSketch()
         sk.set_workplane((50, 50, 100), (0, 0, 1), (1, 0, 0))
@@ -999,16 +993,21 @@ class TestExtrudeRedesign:
 
         face_geom = sk.get_geometry()
         result = win._compute_extrude_result(
-            sketch, face_geom,
+            sketch,
-            length=5.0, symmetric=False, invert=False,
+            face_geom,
-            cut=True, union=False, through_all=True,
+            length=5.0,
+            symmetric=False,
+            invert=False,
+            cut=True,
+            union=False,
+            through_all=True,
         )
         assert result is not None
         # Target is the source box, NOT the dict's first body.
         assert result["target_body"].name == "Src"
         vol = self._geometry_volume(win, result["result_geom"])
         # 100^3 - pi*100*100 (through-all full-depth cut on the 100 box).
-        expected = 100.0 ** 3 - math.pi * (10.0 ** 2) * 100.0
+        expected = 100.0**3 - math.pi * (10.0**2) * 100.0
         assert abs(vol - expected) < 1.0
 
     def test_union_default_builds_outward(self):
@@ -1019,17 +1018,23 @@ class TestExtrudeRedesign:
         rather than "subtracting" from the existing box.
         """
         import math
+
         win, sketch, sk, box_obj = self._make_window_with_box(100.0)
         face_geom = self._add_circle(sk, r=10.0)
         result = win._compute_extrude_result(
-            sketch, face_geom,
+            sketch,
-            length=10.0, symmetric=False, invert=False,
+            face_geom,
-            cut=False, union=True, through_all=False,
+            length=10.0,
+            symmetric=False,
+            invert=False,
+            cut=False,
+            union=True,
+            through_all=False,
         )
         assert result is not None
         vol = self._geometry_volume(win, result["result_geom"])
         # 100^3 + pi*100*10 — material added on top.
-        expected = 100.0 ** 3 + math.pi * (10.0 ** 2) * 10.0
+        expected = 100.0**3 + math.pi * (10.0**2) * 10.0
         assert abs(vol - expected) < 1.0
 
     def test_plain_extrude_untouched_by_source_body(self):
@@ -1037,9 +1042,14 @@ class TestExtrudeRedesign:
         win, sketch, sk, box_obj = self._make_window_with_box(100.0)
         face_geom = self._add_circle(sk, r=10.0)
         result = win._compute_extrude_result(
-            sketch, face_geom,
+            sketch,
-            length=10.0, symmetric=False, invert=False,
+            face_geom,
-            cut=False, union=False, through_all=False,
+            length=10.0,
+            symmetric=False,
+            invert=False,
+            cut=False,
+            union=False,
+            through_all=False,
         )
         assert result is not None
         # No boolean target; result is the standalone tool extrusion.
@@ -1047,7 +1057,8 @@ class TestExtrudeRedesign:
         vol = self._geometry_volume(win, result["result_geom"])
         # Standalone cylinder 10 mm tall.
         import math
-        assert abs(vol - math.pi * (10.0 ** 2) * 10.0) < 1.0
+
+        assert abs(vol - math.pi * (10.0**2) * 10.0) < 1.0
 
     def test_freshly_picked_sketch_is_auto_selected(self):
         """After _on_face_picked, the new sketch is the current list row.
@@ -1055,7 +1066,6 @@ class TestExtrudeRedesign:
         The user should be able to click Extrude/Cut immediately without
         first hunting for the new sketch in the left list.
         """
-        from fluency.geometry_occ.kernel import OCCGeometryObject
         win, _, sk, box_obj = self._make_window_with_box(100.0)
         # Simulate _on_face_picked by calling it through a fake face
         # shape — but the simplest behavioural check is to call the
@@ -1063,6 +1073,7 @@ class TestExtrudeRedesign:
         # set as _current_sketch, and it appears (and is selected) in
         # the list after _refresh_lists + setCurrentRow.
         from fluency.models.data_model import Sketch
+
         sketch = Sketch(name="Sketch on face 99")
         sketch._source_body_id = "b1"
         sketch.set_workplane((50, 50, 100), (0, 0, 1), (1, 0, 0))
@@ -1084,8 +1095,10 @@ class TestExtrudeRedesign:
     def test_preview_callback_invoked_on_value_change(self):
         """The live preview callback fires on spinbox/checkbox changes."""
         import os
+
         os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
         from PySide6.QtWidgets import QApplication
+
         app = QApplication.instance() or QApplication([])
         from fluency.main import ExtrudeDialog
 
@@ -1110,8 +1123,10 @@ class TestExtrudeRedesign:
     def test_preview_hidden_event_sends_none(self):
         """hideEvent should deliver None to the callback so the host clears."""
         import os
+
         os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
         from PySide6.QtWidgets import QApplication
+
         app = QApplication.instance() or QApplication([])
         from fluency.main import ExtrudeDialog