From 3d63f033f2395d31dcf74d1dc7f08dce572a86d4 Mon Sep 17 00:00:00 2001
From: bklronin <therrmann23@gmail.com>
Date: Sat, 8 Aug 2026 13:46:12 +0200
Subject: [PATCH] - Operation highlighting, body highlighting

---
 .idea/workspace.xml                |  22 +-
 icons/pt_pt.aseprite               | Bin 0 -> 610 bytes
 icons/pt_pt.png                    | Bin 0 -> 267 bytes
 src/fluency/geometry_occ/sketch.py |  53 ++--
 src/fluency/io/project_io.py       |  14 +
 src/fluency/models/data_model.py   |   8 +
 src/fluency/ui/main_window.py      | 427 +++++++++++++++++++++++++++--
 src/fluency/ui/sketch_widget.py    |   7 +-
 8 files changed, 488 insertions(+), 43 deletions(-)
 create mode 100644 icons/pt_pt.aseprite
 create mode 100644 icons/pt_pt.png

diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 5ac5f2a..398539f 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -4,11 +4,13 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="8f0bafd6-58a0-4b20-aa2b-ddc3ba278873" name="Changes" comment="- arc improvements, fillets, operations, bodys">
+    <list default="true" id="8f0bafd6-58a0-4b20-aa2b-ddc3ba278873" name="Changes" comment="- Operation highlighting, body highlighting">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" 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/geometry_occ/sketch.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/geometry_occ/sketch.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/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" />
+      <change beforePath="$PROJECT_DIR$/src/fluency/ui/sketch_widget.py" beforeDir="false" afterPath="$PROJECT_DIR$/src/fluency/ui/sketch_widget.py" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -503,7 +505,15 @@
       <option name="project" value="LOCAL" />
       <updated>1786125317688</updated>
     </task>
-    <option name="localTasksCounter" value="49" />
+    <task id="LOCAL-00049" summary="- Operation highlighting, body highlighting">
+      <option name="closed" value="true" />
+      <created>1786180549405</created>
+      <option name="number" value="00049" />
+      <option name="presentableId" value="LOCAL-00049" />
+      <option name="project" value="LOCAL" />
+      <updated>1786180549405</updated>
+    </task>
+    <option name="localTasksCounter" value="50" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">
@@ -524,7 +534,6 @@
     <ignored-roots>
       <path value="$PROJECT_DIR$/pythonProject" />
     </ignored-roots>
-    <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" />
     <MESSAGE value="- delete sketch working&#10;- added mid point snap&#10;- added hovering line with distance" />
@@ -549,6 +558,7 @@
     <MESSAGE value="- Render improvements, camera plane, update" />
     <MESSAGE value="- added &quot;measurement lines&quot;" />
     <MESSAGE value="- arc improvements, fillets, operations, bodys" />
-    <option name="LAST_COMMIT_MESSAGE" value="- arc improvements, fillets, operations, bodys" />
+    <MESSAGE value="- Operation highlighting, body highlighting" />
+    <option name="LAST_COMMIT_MESSAGE" value="- Operation highlighting, body highlighting" />
   </component>
 </project>
\ No newline at end of file
diff --git a/icons/pt_pt.aseprite b/icons/pt_pt.aseprite
new file mode 100644
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GIT binary patch
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HcmV?d00001

diff --git a/icons/pt_pt.png b/icons/pt_pt.png
new file mode 100644
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GIT binary patch
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diff --git a/src/fluency/geometry_occ/sketch.py b/src/fluency/geometry_occ/sketch.py
index 9300bf1..6316da1 100644
--- a/src/fluency/geometry_occ/sketch.py
+++ b/src/fluency/geometry_occ/sketch.py
@@ -1949,7 +1949,7 @@ class OCCSketch(SketchInterface):
 
     _SNAP_TOL: float = 1e-2  # world-unit tolerance for snapping line endpoints in loop detection
 
-    def _line_segments(self) -> List[Tuple[Tuple[float, float], Tuple[float, float]]]:
+    def _line_segments(self) -> List[Tuple[float, float, float, float, int]]:
         """Current line segments as world-coordinate tuples (uses solved positions).
 
         Returns both straight line segments AND tessellated arc segments so
@@ -1957,10 +1957,13 @@ class OCCSketch(SketchInterface):
         and external entities are excluded — they're reference geometry and
         must not affect the sketch profile.
 
+        Each segment is ``(x1, y1, x2, y2, entity_id)`` — the entity_id lets
+        callers trace which sketch entity produced each segment.
+
         Tessellation density: roughly 12 segments per π radians of arc sweep,
         which gives smooth-looking closed loops for face detection.
         """
-        segs: List[Tuple[Tuple[float, float], Tuple[float, float]]] = []
+        segs: List[Tuple[float, float, float, float, int]] = []
 
         # ── Straight line segments ──
         for line_id, (sid, eid2) in self._lines.items():
@@ -1974,8 +1977,9 @@ class OCCSketch(SketchInterface):
             if s_ent and e_ent and s_ent.geometry and e_ent.geometry:
                 segs.append(
                     (
-                        (float(s_ent.geometry[0]), float(s_ent.geometry[1])),
-                        (float(e_ent.geometry[0]), float(e_ent.geometry[1])),
+                        float(s_ent.geometry[0]), float(s_ent.geometry[1]),
+                        float(e_ent.geometry[0]), float(e_ent.geometry[1]),
+                        line_id,
                     )
                 )
 
@@ -2010,7 +2014,7 @@ class OCCSketch(SketchInterface):
                 a2 = start_angle + t2 * sweep
                 p1 = (cx + radius * math.cos(a1), cy + radius * math.sin(a1))
                 p2 = (cx + radius * math.cos(a2), cy + radius * math.sin(a2))
-                segs.append((p1, p2))
+                segs.append((p1[0], p1[1], p2[0], p2[1], arc_id))
 
         return segs
 
@@ -2018,8 +2022,8 @@ class OCCSketch(SketchInterface):
         """Detect closed loops: polygon cycles from connected lines + each circle.
 
         Each loop is one of:
-          {"type": "polygon", "points": [(x,y), ...]}  (closed, last == first)
-          {"type": "circle", "center": (x,y), "radius": r}
+          {"type": "polygon", "points": [(x,y), ...], "entity_ids": [int, ...]}  (closed, last == first)
+          {"type": "circle", "center": (x,y), "radius": r, "entity_ids": [int]}
         Line endpoint coordinates are snapped to ``_SNAP_TOL`` so a closed
         rectangle's four corners join into one cycle even after solver floating
         point jitter. Only connected components where every node has degree 2
@@ -2035,11 +2039,13 @@ class OCCSketch(SketchInterface):
 
             reprs: Dict[Any, Tuple[float, float]] = {}  # key -> averaged world pt
             edges: List[Tuple[Any, Any]] = []
-            for p1, p2 in segs:
-                k1, k2 = key(p1), key(p2)
-                reprs.setdefault(k1, p1)
-                reprs.setdefault(k2, p2)
+            edge_eids: Dict[Tuple[Any, Any], int] = {}  # (k1,k2) -> entity_id
+            for x1, y1, x2, y2, eid in segs:
+                k1, k2 = key((x1, y1)), key((x2, y2))
+                reprs.setdefault(k1, (x1, y1))
+                reprs.setdefault(k2, (x2, y2))
                 edges.append((k1, k2))
+                edge_eids[(k1, k2) if k1 < k2 else (k2, k1)] = eid
 
             # Undirected adjacency.
             adj: Dict[Any, List[Any]] = {}
@@ -2066,8 +2072,9 @@ class OCCSketch(SketchInterface):
                         if nb not in comp_seen:
                             stack.append(nb)
                 if all(len(adj[n]) == 2 for n in comp) and len(comp) >= 3:
-                    # Order the cycle by following each node's neighbor not yet visited.
+                    # Order the cycle by following each node's neighbour not yet visited.
                     ordered: List[Any] = []
+                    eids: List[int] = []
                     cur = comp[0]
                     prev = None
                     for _ in range(len(comp)):
@@ -2075,16 +2082,26 @@ class OCCSketch(SketchInterface):
                         nbrs = [nb for nb in adj[cur] if nb != prev]
                         if not nbrs:
                             break
+                        ekey = (cur, nbrs[0]) if cur < nbrs[0] else (nbrs[0], cur)
+                        if ekey in edge_eids:
+                            eids.append(edge_eids[ekey])
                         prev = cur
                         cur = nbrs[0]
                     if len(ordered) == len(comp):
                         pts = [reprs[k] for k in ordered]
                         pts.append(pts[0])
-                        loops.append({"type": "polygon", "points": pts})
+                        loops.append(
+                            {"type": "polygon", "points": pts, "entity_ids": sorted(set(eids))}
+                        )
                 seen |= comp_seen
 
         # Circles are closed loops of their own.
         for cid, (center_id, r) in self._circles.items():
+            circle_ent = self._entities.get(cid)
+            if circle_ent is not None and circle_ent.is_construction:
+                continue
+            if cid in self._external_entity_ids:
+                continue
             c_ent = self._entities.get(center_id)
             if c_ent and c_ent.geometry and r > 0:
                 loops.append(
@@ -2092,6 +2109,7 @@ class OCCSketch(SketchInterface):
                         "type": "circle",
                         "center": (float(c_ent.geometry[0]), float(c_ent.geometry[1])),
                         "radius": float(r),
+                        "entity_ids": [cid],
                     }
                 )
         return loops
@@ -2242,8 +2260,7 @@ class OCCSketch(SketchInterface):
         that is the rectangle minus the circle — exactly the
         "shape within a shape = closed without inner" behavior. A shape nested
         inside a hole (depth 2) becomes its own solid face again.
-
-        Returns a list of ``{"outer": loop, "holes": [loop, ...], "depth": int}``.
+        Returns a list of ``{"outer": loop, "holes": [loop, ...], "depth": int, "entity_ids": [int, ...]}``.
         """
         loops = self.get_closed_loops()
         if not loops:
@@ -2267,7 +2284,11 @@ class OCCSketch(SketchInterface):
                 # directly nested: depth one greater, and outer contains inner.
                 if depths[j] == depths[i] + 1 and OCCSketch._loop_contains(inner, outer):
                     holes.append(inner)
-            faces.append({"outer": outer, "holes": holes, "depth": depths[i]})
+            # Face entity_ids = union of outer + hole loop entity_ids.
+            eids = set(outer.get("entity_ids", []))
+            for h in holes:
+                eids.update(h.get("entity_ids", []))
+            faces.append({"outer": outer, "holes": holes, "depth": depths[i], "entity_ids": sorted(eids)})
         return faces
 
     def find_face_at(self, x: float, y: float) -> Optional[Dict[str, Any]]:
diff --git a/src/fluency/io/project_io.py b/src/fluency/io/project_io.py
index 9d1f864..1aa712f 100644
--- a/src/fluency/io/project_io.py
+++ b/src/fluency/io/project_io.py
@@ -226,6 +226,8 @@ def _feature_to_dict(feat: Feature) -> Dict[str, Any]:
         "tangent_propagation": bool(feat.tangent_propagation),
         "scope": feat.scope,
         "edge_refs": list(feat.edge_refs),
+        "face_keys": json.dumps(feat.face_keys) if feat.face_keys is not None else None,
+        "face_keys_sketch_id": feat.face_keys_sketch_id,
         "pattern_type": feat.pattern_type,
         "count": feat.count,
         "spacing": feat.spacing,
@@ -256,6 +258,8 @@ def _feature_from_dict(data: Dict[str, Any], sketches: Dict[str, Sketch]) -> Fea
         tangent_propagation=bool(data.get("tangent_propagation", False)),
         scope=data.get("scope", "selected"),
         edge_refs=list(data.get("edge_refs") or []),
+        face_keys=None,
+        face_keys_sketch_id=data.get("face_keys_sketch_id"),
         pattern_type=data.get("pattern_type", "linear"),
         count=int(data.get("count") or 2),
         spacing=_to_float(data.get("spacing"), 10.0),
@@ -264,6 +268,16 @@ def _feature_from_dict(data: Dict[str, Any], sketches: Dict[str, Sketch]) -> Fea
         mirror_plane_normal=tuple(float(v) for v in (data.get("mirror_plane_normal") or (1, 0, 0))),
         keep_original=bool(data.get("keep_original", True)),
     )
+
+    # Deserialize face_keys from JSON if present.
+    fk_raw = data.get("face_keys")
+    if fk_raw and isinstance(fk_raw, str):
+        try:
+            feat.face_keys = json.loads(fk_raw)
+        except (json.JSONDecodeError, TypeError):
+            pass
+    elif isinstance(fk_raw, list):
+        feat.face_keys = fk_raw
     sid = data.get("sketch_id")
     if sid and sid in sketches:
         feat.sketch = sketches[sid]
diff --git a/src/fluency/models/data_model.py b/src/fluency/models/data_model.py
index 924f743..89bc32d 100644
--- a/src/fluency/models/data_model.py
+++ b/src/fluency/models/data_model.py
@@ -275,6 +275,14 @@ class Feature:
     scope: str = "selected"
     edge_refs: List[str] = field(default_factory=list)
 
+    # FaceKey references for fillet/chamfer: stable face classification
+    # that survives sketch dimension changes.  ``face_keys`` is a list of
+    # (FaceKey, FaceKey) pairs — one pair per user-picked face;
+    # ``face_keys_sketch_id`` tracks which sketch produced the body these
+    # faces belong to.
+    face_keys: Optional[List[Tuple[Dict[str, Any], Dict[str, Any]]]] = None
+    face_keys_sketch_id: Optional[str] = None
+
     # "array" / "pattern" features only: repeat the running solid.
     # ``pattern_type`` is "linear" or "circular"; ``count`` is the total
     # number of items including the original.  Linear arrays use
diff --git a/src/fluency/ui/main_window.py b/src/fluency/ui/main_window.py
index 2643d19..92ab4bc 100644
--- a/src/fluency/ui/main_window.py
+++ b/src/fluency/ui/main_window.py
@@ -274,7 +274,7 @@ def _make_component_thumbnail(
         py_min, py_max = all_py.min(), all_py.max()
         span_x = px_max - px_min
         span_y = py_max - py_min
-        if span_x < 1e-10 or span_y < 1e-10:
+        if span_x < 1e-6 or span_y < 1e-6:
             return None
 
         # Scale to fill ~90% of the image
@@ -820,6 +820,229 @@ def _feature_face_geometry(body: Body, feat: Feature, occ_sketch: OCCSketch) ->
     return face_geom
 
 
+
+def _classify_extruded_faces(
+    body_shape: Any,
+    sketch: OCCSketch,
+    workplane_origin: Tuple[float, float, float],
+    workplane_normal: Tuple[float, float, float],
+) -> Dict[int, Dict[str, Any]]:
+    """Classify every face of *body_shape* relative to the extrusion sketch.
+
+    Returns ``{face_index: FaceKey}`` where each FaceKey is:
+
+    - ``{"type": "cap", "top": bool, "entity_ids": [int, ...]}``
+    - ``{"type": "lateral", "entity_ids": [int, ...]}``
+
+    *entity_ids* are the sketch entity IDs whose extrusion produced the face.
+    """
+    import numpy as np
+    from OCP.TopExp import TopExp_Explorer
+    from OCP.TopAbs import TopAbs_FACE, TopAbs_EDGE
+    from OCP.TopoDS import TopoDS
+    from OCP.BRepAdaptor import BRepAdaptor_Surface, BRepAdaptor_Curve
+    from OCP.GeomAbs import GeomAbs_Plane
+    from OCP.BRepGProp import BRepGProp
+    from OCP.GProp import GProp_GProps
+    from OCP.BRep import BRep_Tool
+    from OCP.gp import gp_Pnt
+
+    # Workplane frame.
+    origin = np.asarray(workplane_origin, dtype=float)
+    normal = np.asarray(workplane_normal, dtype=float)
+    normal = normal / (np.linalg.norm(normal) + 1e-30)
+
+    # Infer x_dir from sketch workplane (needed for UV projection).
+    wp = sketch.get_workplane()
+    x_dir = np.asarray(wp[2], dtype=float) if len(wp) > 2 else np.array([1.0, 0.0, 0.0], dtype=float)
+    x_dir = x_dir / (np.linalg.norm(x_dir) + 1e-30)
+    y_dir = np.cross(normal, x_dir)
+    y_dir = y_dir / (np.linalg.norm(y_dir) + 1e-30)
+
+    def _world_to_uv(p3d):
+        v = np.array([p3d[0] - origin[0], p3d[1] - origin[1], p3d[2] - origin[2]], dtype=float)
+        return (float(np.dot(v, x_dir)), float(np.dot(v, y_dir)))
+
+    def _face_center(face):
+        props = GProp_GProps()
+        BRepGProp.SurfaceProperties_s(face, props)
+        c = props.CentreOfMass()
+        return (float(c.X()), float(c.Y()), float(c.Z()))
+
+    def _point_to_segment_dist_sq(px, py, ax, ay, bx, by):
+        """Squared distance from point P to segment AB."""
+        dx, dy = bx - ax, by - ay
+        if abs(dx) < 1e-12 and abs(dy) < 1e-12:
+            return (px - ax) ** 2 + (py - ay) ** 2
+        t = max(0.0, min(1.0, ((px - ax) * dx + (py - ay) * dy) / (dx * dx + dy * dy)))
+        return (px - (ax + t * dx)) ** 2 + (py - (ay + t * dy)) ** 2
+
+    # ── 1. Collect all faces ──
+    all_faces: list = []
+    ex = TopExp_Explorer(body_shape, TopAbs_FACE)
+    while ex.More():
+        all_faces.append(TopoDS.Face_s(ex.Current()))
+        ex.Next()
+
+    # ── 2. Classify each face as cap or lateral ──
+    cap_faces: list = []        # (face, center_3d, top)
+    lateral_faces: list = []    # (face, index)
+    face_idx: Dict[Any, int] = {}
+
+    for idx, face in enumerate(all_faces):
+        face_idx[face] = idx
+        try:
+            surf = BRepAdaptor_Surface(face)
+            if surf.GetType() != GeomAbs_Plane:
+                continue
+            plane = surf.Plane()
+            fn = np.array(
+                [plane.Axis().Direction().X(), plane.Axis().Direction().Y(), plane.Axis().Direction().Z()],
+                dtype=float,
+            )
+            cos_angle = abs(float(np.dot(normal, fn)))
+            center = _face_center(face)
+            if cos_angle > 0.999:
+                cap_faces.append((face, center))
+            else:
+                lateral_faces.append((face, idx))
+        except Exception:
+            continue
+
+    # Determine top/bottom: sort cap faces by signed distance along normal,
+    # top = larger projection.
+    if cap_faces:
+        cap_projections = [
+            float(np.dot(np.asarray(c) - origin, normal)) for _, c in cap_faces
+        ]
+        mid = (min(cap_projections) + max(cap_projections)) / 2.0
+        cap_faces = [(f, c, float(np.dot(np.asarray(c) - origin, normal)) > mid) for (f, c) in cap_faces]
+
+    # Build set of cap face shapes for lateral edge matching.
+    cap_face_shapes = {f for f, _, _ in cap_faces}
+
+    def _edges_of_face(face):
+        edges = []
+        ex2 = TopExp_Explorer(face, TopAbs_EDGE)
+        while ex2.More():
+            edges.append(TopoDS.Edge_s(ex2.Current()))
+            ex2.Next()
+        return edges
+
+    # ── 3. Helper: nearest sketch entity to a UV point ──
+    def _nearest_entity_id(uv_pt):
+        """Find the ID of the sketch entity nearest to *uv_pt* in UV space."""
+        best_id = None
+        best_dist = float("inf")
+        ux, uy = uv_pt
+
+        # Check lines.
+        for line_id, (sid, eid2) in sketch._lines.items():
+            if line_id in sketch._external_entity_ids:
+                continue
+            ent = sketch._entities.get(line_id)
+            if ent is not None and ent.is_construction:
+                continue
+            s_ent = sketch._entities.get(sid)
+            e_ent = sketch._entities.get(eid2)
+            if not (s_ent and e_ent and s_ent.geometry and e_ent.geometry):
+                continue
+            d2 = _point_to_segment_dist_sq(
+                ux, uy,
+                float(s_ent.geometry[0]), float(s_ent.geometry[1]),
+                float(e_ent.geometry[0]), float(e_ent.geometry[1]),
+            )
+            if d2 < best_dist:
+                best_dist = d2
+                best_id = line_id
+
+        # Check circles.
+        for cid, (center_id, r) in sketch._circles.items():
+            if cid in sketch._external_entity_ids:
+                continue
+            ent = sketch._entities.get(cid)
+            if ent is not None and ent.is_construction:
+                continue
+            c_ent = sketch._entities.get(center_id)
+            if not (c_ent and c_ent.geometry):
+                continue
+            cx, cy = float(c_ent.geometry[0]), float(c_ent.geometry[1])
+            d2 = (math.sqrt((ux - cx) ** 2 + (uy - cy) ** 2) - float(r)) ** 2
+            if d2 < best_dist:
+                best_dist = d2
+                best_id = cid
+
+        # Check arcs.
+        for arc_id, arc_data in sketch._arcs.items():
+            ent = sketch._entities.get(arc_id)
+            if ent is not None and ent.is_construction:
+                continue
+            center_id = arc_data.get("center")
+            radius = arc_data.get("radius", 0.0)
+            c_ent = sketch._entities.get(center_id)
+            if not (c_ent and c_ent.geometry and radius > 0):
+                continue
+            cx, cy = float(c_ent.geometry[0]), float(c_ent.geometry[1])
+            d2 = (math.sqrt((ux - cx) ** 2 + (uy - cy) ** 2) - float(radius)) ** 2
+            if d2 < best_dist:
+                best_dist = d2
+                best_id = arc_id
+
+        return best_id
+
+    # ── 4. Build result ──
+    result: Dict[int, Dict[str, Any]] = {}
+
+    for face, center, top in cap_faces:
+        uv = _world_to_uv(center)
+        sketch_face = sketch.find_face_at(uv[0], uv[1])
+        eids = sketch_face.get("entity_ids", []) if sketch_face else []
+        result[face_idx[face]] = {"type": "cap", "top": top, "entity_ids": sorted(eids)}
+
+    for face, idx in lateral_faces:
+        # Find edges this lateral face shares with any cap face.
+        lat_edges = _edges_of_face(face)
+        cap_adj_edges = []
+        for le in lat_edges:
+            for cf in cap_face_shapes:
+                for ce in _edges_of_face(cf):
+                    if le.IsSame(ce):
+                        cap_adj_edges.append(le)
+                        break
+
+        # Project midpoints of cap-adjacent edges to UV and match sketch entities.
+        eids: set = set()
+        for edge in cap_adj_edges:
+            try:
+                ac = BRepAdaptor_Curve(edge)
+                mid_param = (ac.FirstParameter() + ac.LastParameter()) / 2.0
+                mp = ac.Value(mid_param)
+                uv = _world_to_uv((mp.X(), mp.Y(), mp.Z()))
+                eid = _nearest_entity_id(uv)
+                if eid is not None:
+                    eids.add(eid)
+            except Exception:
+                continue
+
+        # Fallback: if no cap-adjacent edges found (e.g., non-prismatic body),
+        # project the face's own boundary edges.
+        if not eids:
+            for edge in lat_edges:
+                try:
+                    ac = BRepAdaptor_Curve(edge)
+                    mid_param = (ac.FirstParameter() + ac.LastParameter()) / 2.0
+                    mp = ac.Value(mid_param)
+                    uv = _world_to_uv((mp.X(), mp.Y(), mp.Z()))
+                    eid = _nearest_entity_id(uv)
+                    if eid is not None:
+                        eids.add(eid)
+                except Exception:
+                    continue
+
+        result[idx] = {"type": "lateral", "entity_ids": sorted(eids)}
+
+    return result
+
 # ── Fillet edge helpers ─────────────────────────────────────────────────────
 
 
@@ -1018,11 +1241,69 @@ def _resolve_edges_by_fingerprint(shape: Any, refs: List[str]) -> List[Any]:
     return out
 
 
+def _resolve_edges_by_face_keys(
+    shape: Any, feat: Feature, component: Optional[Any]
+) -> Optional[List[Any]]:
+    """Try to resolve fillet/chamfer edges using FaceKey classification.
+
+    Returns a list of seed edges if resolution succeeds, *None* if it
+    doesn't (so the caller can fall back to fingerprint matching).
+    """
+    if feat.face_keys is None or len(feat.face_keys) != 1:
+        return None
+    if component is None or feat.face_keys_sketch_id is None:
+        return None
+    sk = component.sketches.get(feat.face_keys_sketch_id)
+    if sk is None or sk.occ_sketch is None:
+        return None
+
+    try:
+        face_map = _classify_extruded_faces(
+            shape,
+            sk.occ_sketch,
+            tuple(sk.workplane_origin.tolist()),
+            tuple(sk.workplane_normal.tolist()),
+        )
+    except Exception:
+        return None
+
+    key_a, key_b = feat.face_keys[0]
+
+    # Find matching faces by FaceKey content.
+    from OCP.TopoDS import TopoDS as _TopoDS
+    from OCP.TopExp import TopExp_Explorer as _TopExp_Explorer
+    from OCP.TopAbs import TopAbs_FACE as _TopAbs_FACE
+
+    face_a = face_b = None
+    ex2 = _TopExp_Explorer(shape, _TopAbs_FACE)
+    idx = 0
+    while ex2.More():
+        face_obj = _TopoDS.Face_s(ex2.Current())
+        fk = face_map.get(idx)
+        if fk is not None:
+            if fk == key_a:
+                face_a = face_obj
+            if fk == key_b:
+                face_b = face_obj
+        idx += 1
+        ex2.Next()
+
+    if face_a is None or face_b is None:
+        return None
+
+    seed_edges = _shared_edges_between_faces(shape, face_a, face_b)
+    if not seed_edges:
+        return None
+
+    return _resolve_fillet_edges(shape, seed_edges, feat.tangent_propagation, feat.scope)
+
+
 def _replay_body_features(
     kernel: OCGeometryKernel,
     body: Body,
     features: List[Feature],
     through_all_length_fn: Callable[[Any, Sketch], float],
+    component: Optional[Any] = None,  # Component for FaceKey sketch lookup
 ) -> Optional[Any]:
     """Replay *features* in order and return the resulting geometry.
 
@@ -1047,19 +1328,28 @@ def _replay_body_features(
             if feat.radius is None:
                 logger.warning(f"Body '{body.name}': fillet feature has no radius, replay aborted")
                 return None
-            if feat.scope == "all" or not feat.edge_refs:
+            if feat.scope == "all":
                 edges: Optional[List[Any]] = None  # round every edge
+            elif feat.face_keys is not None:
+                # Try FaceKey resolution first (survives dimensional changes),
+                # fall back to edge fingerprints.
+                edges = _resolve_edges_by_face_keys(geom.shape, feat, component)
+                if edges is None:
+                    edges = _resolve_edges_by_fingerprint(geom.shape, feat.edge_refs)
+                if not edges:
+                    logger.warning(
+                        f"Body '{body.name}': fillet edge refs unresolved after rebuild, "
+                        "skipping fillet"
+                    )
+                    continue
             else:
                 edges = _resolve_edges_by_fingerprint(geom.shape, feat.edge_refs)
                 if not edges:
-                    # The referenced edges no longer exist after a topology
-                    # change — abort so the body keeps its previous state
-                    # (marked ⚠) instead of silently rounding nothing.
                     logger.warning(
                         f"Body '{body.name}': fillet edge refs unresolved after rebuild, "
-                        "replay aborted"
+                        "skipping fillet"
                     )
-                    return None
+                    continue
             geom = kernel.fillet(geom, feat.radius, edges=edges)
             if geom is None:
                 return None
@@ -1073,20 +1363,26 @@ def _replay_body_features(
             if feat.radius is None:
                 logger.warning(f"Body '{body.name}': chamfer feature has no size, replay aborted")
                 return None
-            if feat.scope == "all" or not feat.edge_refs:
-                edges = None  # bevel every edge
+            if feat.scope == "all":
+                edges: Optional[List[Any]] = None  # bevel every edge
+            elif feat.face_keys is not None:
+                edges = _resolve_edges_by_face_keys(geom.shape, feat, component)
+                if edges is None:
+                    edges = _resolve_edges_by_fingerprint(geom.shape, feat.edge_refs)
+                if not edges:
+                    logger.warning(
+                        f"Body '{body.name}': chamfer edge refs unresolved after rebuild, "
+                        "skipping chamfer"
+                    )
+                    continue
             else:
                 edges = _resolve_edges_by_fingerprint(geom.shape, feat.edge_refs)
                 if not edges:
                     logger.warning(
                         f"Body '{body.name}': chamfer edge refs unresolved after rebuild, "
-                        "replay aborted"
+                        "skipping chamfer"
                     )
-                    return None
-            geom = kernel.chamfer(geom, feat.radius, edges=edges)
-            if geom is None:
-                return None
-            continue
+                    continue
 
         if feat.operation in ("array", "pattern"):
             # Pattern needs no sketch — it repeats the running solid.
@@ -2374,6 +2670,7 @@ class MainWindow(QMainWindow):
         geom = _replay_body_features(
             self._kernel, body, features[: index + 1],
             self._through_all_length_for_geometry,
+            component=self._current_component,
         )
         if geom is None:
             return None
@@ -2400,11 +2697,11 @@ class MainWindow(QMainWindow):
         if face_geom is None:
             return None
 
-        # For through-all cuts we need the pre-op body to size the tool.
         if feat.through_all:
             pre_geom = _replay_body_features(
                 self._kernel, body, features[:index],
                 self._through_all_length_for_geometry,
+                component=self._current_component,
             )
             if pre_geom is not None:
                 length = self._through_all_length_for_geometry(pre_geom, sketch)
@@ -2544,9 +2841,9 @@ class MainWindow(QMainWindow):
                 self._viewer_3d.clear_preview()
                 return
             try:
-                # Replay features up to and including the selected one.
                 geom = _replay_body_features(
-                    self._kernel, body, features[: index + 1], self._through_all_length_for_geometry
+                    self._kernel, body, features[: index + 1], self._through_all_length_for_geometry,
+                    component=self._current_component,
                 )
                 if geom is None:
                     self._viewer_3d.clear_preview()
@@ -2689,7 +2986,8 @@ class MainWindow(QMainWindow):
 
             try:
                 new_geom = _replay_body_features(
-                    self._kernel, body, features, self._through_all_length_for_geometry
+                    self._kernel, body, features, self._through_all_length_for_geometry,
+                    component=self._current_component,
                 )
             except Exception as exc:
                 logger.exception(f"Body '{body.name}': feature replay failed: {exc}")
@@ -6573,6 +6871,51 @@ class MainWindow(QMainWindow):
         if not features and body.geometry is not None:
             # Imported / baked body: freeze current geometry as the base.
             features.append(Feature(operation="base", geometry=body.geometry))
+
+        # ── Compute FaceKeys for stable replay across dimension changes ──
+        face_keys = None
+        face_keys_sketch_id = None
+        if scope != "all" and self._fillet_face1 is not None and self._fillet_face2 is not None:
+            # Find the last sketch-producing feature before this fillet.
+            sketch_feat: Optional[Feature] = None
+            for f in reversed(features):
+                if f.operation in ("extrude", "revolve", "cut", "union") and f.sketch is not None:
+                    sketch_feat = f
+                    break
+            if sketch_feat is not None and sketch_feat.sketch is not None:
+                sk = sketch_feat.sketch
+                if sk.occ_sketch is not None:
+                    try:
+                        face_map = _classify_extruded_faces(
+                            shape,
+                            sk.occ_sketch,
+                            tuple(sk.workplane_origin.tolist()),
+                            tuple(sk.workplane_normal.tolist()),
+                        )
+                        # Re-iterate faces in the same TopExp order to get
+                        # actual face objects for IsSame comparison.
+                        from OCP.TopoDS import TopoDS as _TopoDS
+                        from OCP.TopExp import TopExp_Explorer as _TopExp_Explorer
+                        from OCP.TopAbs import TopAbs_FACE as _TopAbs_FACE
+                        key_a = key_b = None
+                        ex2 = _TopExp_Explorer(shape, _TopAbs_FACE)
+                        idx = 0
+                        while ex2.More():
+                            face_obj = _TopoDS.Face_s(ex2.Current())
+                            fk = face_map.get(idx)
+                            if fk is not None:
+                                if face_obj.IsSame(self._fillet_face1):
+                                    key_a = fk
+                                if face_obj.IsSame(self._fillet_face2):
+                                    key_b = fk
+                            idx += 1
+                            ex2.Next()
+                        if key_a is not None and key_b is not None:
+                            face_keys = [(key_a, key_b)]
+                            face_keys_sketch_id = sk.id
+                    except Exception:
+                        logger.debug("FaceKey classification failed for fillet", exc_info=True)
+
         features.append(
             Feature(
                 operation="fillet",
@@ -6580,6 +6923,8 @@ class MainWindow(QMainWindow):
                 tangent_propagation=tangent_propagation,
                 scope=scope,
                 edge_refs=[_edge_fingerprint(e) for e in (edges or [])],
+                face_keys=face_keys,
+                face_keys_sketch_id=face_keys_sketch_id,
             )
         )
 
@@ -6752,6 +7097,48 @@ class MainWindow(QMainWindow):
         features = _ensure_feature_history(body)
         if not features and body.geometry is not None:
             features.append(Feature(operation="base", geometry=body.geometry))
+
+        # ── Compute FaceKeys for stable replay across dimension changes ──
+        face_keys = None
+        face_keys_sketch_id = None
+        if scope != "all" and self._chamfer_face1 is not None and self._chamfer_face2 is not None:
+            sketch_feat: Optional[Feature] = None
+            for f in reversed(features):
+                if f.operation in ("extrude", "revolve", "cut", "union") and f.sketch is not None:
+                    sketch_feat = f
+                    break
+            if sketch_feat is not None and sketch_feat.sketch is not None:
+                sk = sketch_feat.sketch
+                if sk.occ_sketch is not None:
+                    try:
+                        face_map = _classify_extruded_faces(
+                            shape,
+                            sk.occ_sketch,
+                            tuple(sk.workplane_origin.tolist()),
+                            tuple(sk.workplane_normal.tolist()),
+                        )
+                        from OCP.TopoDS import TopoDS as _TopoDS
+                        from OCP.TopExp import TopExp_Explorer as _TopExp_Explorer
+                        from OCP.TopAbs import TopAbs_FACE as _TopAbs_FACE
+                        key_a = key_b = None
+                        ex2 = _TopExp_Explorer(shape, _TopAbs_FACE)
+                        idx = 0
+                        while ex2.More():
+                            face_obj = _TopoDS.Face_s(ex2.Current())
+                            fk = face_map.get(idx)
+                            if fk is not None:
+                                if face_obj.IsSame(self._chamfer_face1):
+                                    key_a = fk
+                                if face_obj.IsSame(self._chamfer_face2):
+                                    key_b = fk
+                            idx += 1
+                            ex2.Next()
+                        if key_a is not None and key_b is not None:
+                            face_keys = [(key_a, key_b)]
+                            face_keys_sketch_id = sk.id
+                    except Exception:
+                        logger.debug("FaceKey classification failed for chamfer", exc_info=True)
+
         features.append(
             Feature(
                 operation="chamfer",
@@ -6759,6 +7146,8 @@ class MainWindow(QMainWindow):
                 tangent_propagation=tangent_propagation,
                 scope=scope,
                 edge_refs=[_edge_fingerprint(e) for e in (edges or [])],
+                face_keys=face_keys,
+                face_keys_sketch_id=face_keys_sketch_id,
             )
         )
 
diff --git a/src/fluency/ui/sketch_widget.py b/src/fluency/ui/sketch_widget.py
index d5adaf1..efe463a 100644
--- a/src/fluency/ui/sketch_widget.py
+++ b/src/fluency/ui/sketch_widget.py
@@ -260,6 +260,7 @@ class Sketch2DWidget(QWidget):
         self._move_anchor_orig: Optional[QPoint] = None
         self._move_orig_positions: Dict[int, Tuple[float, float]] = {}
         self._move_active: bool = False
+        self._move_did_move: bool = False
 
         # Auto-constraint tracking on snap
         self._snap_point_target: Optional[OCCSketchEntity] = None
@@ -811,6 +812,7 @@ class Sketch2DWidget(QWidget):
         self._move_anchor_orig = None
         self._move_orig_positions = {}
         self._move_active = False
+        self._move_did_move = False
         self._hovered_face = None
         self._snap_point_target = None
         self._snap_line_target = None
@@ -2317,6 +2319,8 @@ class Sketch2DWidget(QWidget):
             target_world = self._screen_to_world(snapped_screen)
             dx = target_world.x() - self._move_anchor_orig.x()
             dy = target_world.y() - self._move_anchor_orig.y()
+            if dx != 0 or dy != 0:
+                self._move_did_move = True
             for ent in self._moving_points:
                 if ent.id in self._move_orig_positions and ent.geometry is not None:
                     ox, oy = self._move_orig_positions[ent.id]
@@ -2514,8 +2518,7 @@ class Sketch2DWidget(QWidget):
                     # the user expects from dragging a single corner.
                     if self._move_anchor is not None and self._move_anchor.geometry is not None:
                         ax, ay = self._move_anchor.geometry
-                        if not self._sketch.is_entity_dragged(self._move_anchor.id):
-                            self._sketch.constrain_fixed(self._move_anchor)
+                        if self._move_did_move and not self._sketch.is_entity_dragged(self._move_anchor.id):
                             # constrain_fixed reads the current params via
                             # the dragged() call, so re-sync to be safe.
                             self._solve_and_sync()