From c78d0af78c716d62736544980696918fbcdb359a Mon Sep 17 00:00:00 2001
From: bklronin <therrmann23@gmail.com>
Date: Mon, 13 Jul 2026 06:54:21 +0200
Subject: [PATCH] -  added renderer - Added undo

---
 .idea/workspace.xml                  | 86 ++++++++++++++-----------
 src/fluency/rendering/occ_to_mesh.py | 96 ++++++++++------------------
 2 files changed, 80 insertions(+), 102 deletions(-)

diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index f1cabc3..523523d 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -43,45 +43,45 @@
     <option name="hideEmptyMiddlePackages" value="true" />
     <option name="showLibraryContents" value="true" />
   </component>
-  <component name="PropertiesComponent"><![CDATA[{
-  "keyToString": {
-    "Python.2dtest.executor": "Run",
-    "Python.3d_windows.executor": "Run",
-    "Python.Unnamed.executor": "Run",
-    "Python.base.executor": "Run",
-    "Python.data_model.executor": "Run",
-    "Python.draw_widget2d.executor": "Run",
-    "Python.draw_widget_solve.executor": "Run",
-    "Python.fluency.executor": "Run",
-    "Python.fluencyb.executor": "Run",
-    "Python.gl_widget.executor": "Run",
-    "Python.gui_ui.executor": "Run",
-    "Python.kernel.executor": "Run",
-    "Python.main.executor": "Run",
-    "Python.meshtest.executor": "Run",
-    "Python.occ_renderer.executor": "Run",
-    "Python.occ_to_mesh.executor": "Run",
-    "Python.render_backend.executor": "Run",
-    "Python.side_fluency.executor": "Run",
-    "Python.simple_mesh.executor": "Run",
-    "Python.sketch.executor": "Run",
-    "Python.vtk_widget.executor": "Run",
-    "Python.vulkan.executor": "Run",
-    "RunOnceActivity.OpenProjectViewOnStart": "true",
-    "RunOnceActivity.ShowReadmeOnStart": "true",
-    "RunOnceActivity.TerminalTabsStorage.copyFrom.TerminalArrangementManager.252": "true",
-    "RunOnceActivity.git.unshallow": "true",
-    "RunOnceActivity.typescript.service.memoryLimit.init": "true",
-    "codeWithMe.voiceChat.enabledByDefault": "false",
-    "git-widget-placeholder": "feature/occ-migration",
-    "last_opened_file_path": "/Volumes/Data_drive/Programming/fluency/src/fluency/rendering",
-    "node.js.detected.package.eslint": "true",
-    "node.js.selected.package.eslint": "(autodetect)",
-    "node.js.selected.package.tslint": "(autodetect)",
-    "nodejs_package_manager_path": "npm",
-    "settings.editor.selected.configurable": "project.propVCSSupport.DirectoryMappings"
+  <component name="PropertiesComponent">{
+  &quot;keyToString&quot;: {
+    &quot;Python.2dtest.executor&quot;: &quot;Run&quot;,
+    &quot;Python.3d_windows.executor&quot;: &quot;Run&quot;,
+    &quot;Python.Unnamed.executor&quot;: &quot;Run&quot;,
+    &quot;Python.base.executor&quot;: &quot;Run&quot;,
+    &quot;Python.data_model.executor&quot;: &quot;Run&quot;,
+    &quot;Python.draw_widget2d.executor&quot;: &quot;Run&quot;,
+    &quot;Python.draw_widget_solve.executor&quot;: &quot;Run&quot;,
+    &quot;Python.fluency.executor&quot;: &quot;Run&quot;,
+    &quot;Python.fluencyb.executor&quot;: &quot;Run&quot;,
+    &quot;Python.gl_widget.executor&quot;: &quot;Run&quot;,
+    &quot;Python.gui_ui.executor&quot;: &quot;Run&quot;,
+    &quot;Python.kernel.executor&quot;: &quot;Run&quot;,
+    &quot;Python.main.executor&quot;: &quot;Run&quot;,
+    &quot;Python.meshtest.executor&quot;: &quot;Run&quot;,
+    &quot;Python.occ_renderer.executor&quot;: &quot;Run&quot;,
+    &quot;Python.occ_to_mesh.executor&quot;: &quot;Run&quot;,
+    &quot;Python.render_backend.executor&quot;: &quot;Run&quot;,
+    &quot;Python.side_fluency.executor&quot;: &quot;Run&quot;,
+    &quot;Python.simple_mesh.executor&quot;: &quot;Run&quot;,
+    &quot;Python.sketch.executor&quot;: &quot;Run&quot;,
+    &quot;Python.vtk_widget.executor&quot;: &quot;Run&quot;,
+    &quot;Python.vulkan.executor&quot;: &quot;Run&quot;,
+    &quot;RunOnceActivity.OpenProjectViewOnStart&quot;: &quot;true&quot;,
+    &quot;RunOnceActivity.ShowReadmeOnStart&quot;: &quot;true&quot;,
+    &quot;RunOnceActivity.TerminalTabsStorage.copyFrom.TerminalArrangementManager.252&quot;: &quot;true&quot;,
+    &quot;RunOnceActivity.git.unshallow&quot;: &quot;true&quot;,
+    &quot;RunOnceActivity.typescript.service.memoryLimit.init&quot;: &quot;true&quot;,
+    &quot;codeWithMe.voiceChat.enabledByDefault&quot;: &quot;false&quot;,
+    &quot;git-widget-placeholder&quot;: &quot;feature/occ-migration&quot;,
+    &quot;last_opened_file_path&quot;: &quot;/Volumes/Data_drive/Programming/fluency/src/fluency/rendering&quot;,
+    &quot;node.js.detected.package.eslint&quot;: &quot;true&quot;,
+    &quot;node.js.selected.package.eslint&quot;: &quot;(autodetect)&quot;,
+    &quot;node.js.selected.package.tslint&quot;: &quot;(autodetect)&quot;,
+    &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" />
@@ -411,7 +411,15 @@
       <option name="project" value="LOCAL" />
       <updated>1783887704766</updated>
     </task>
-    <option name="localTasksCounter" value="38" />
+    <task id="LOCAL-00038" summary="-  added renderer&#10;- Added undo">
+      <option name="closed" value="true" />
+      <created>1783891561116</created>
+      <option name="number" value="00038" />
+      <option name="presentableId" value="LOCAL-00038" />
+      <option name="project" value="LOCAL" />
+      <updated>1783891561116</updated>
+    </task>
+    <option name="localTasksCounter" value="39" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">
diff --git a/src/fluency/rendering/occ_to_mesh.py b/src/fluency/rendering/occ_to_mesh.py
index 7dcbe14..f52c278 100644
--- a/src/fluency/rendering/occ_to_mesh.py
+++ b/src/fluency/rendering/occ_to_mesh.py
@@ -43,6 +43,8 @@ def occ_shape_to_ply(
     all_faces: List[List[int]] = []
     vertex_offset = 0
 
+    from OCP.TopAbs import TopAbs_FORWARD
+
     explorer = TopExp_Explorer(shape, TopAbs_FACE)
     while explorer.More():
         face = TopoDS.Face_s(explorer.Current())
@@ -56,6 +58,10 @@ def occ_shape_to_ply(
         # Transform
         trsf = location.Transformation()
 
+        # Check face orientation: FORWARD means the surface normal points
+        # outward from the solid; REVERSED means it points inward.
+        is_forward = (face.Orientation() == TopAbs_FORWARD)
+
         # Extract vertices (apply location transform to positions)
         nb_nodes = triangulation.NbNodes()
         for i in range(1, nb_nodes + 1):
@@ -64,15 +70,25 @@ def occ_shape_to_ply(
             all_vertices.append([pnt.X(), pnt.Y(), pnt.Z()])
 
         # Extract triangles
+        # For REVERSED faces, swap winding order (n1, n3, n2) so that
+        # the computed normal points outward consistently.
         nb_triangles = triangulation.NbTriangles()
         for i in range(1, nb_triangles + 1):
             tri = triangulation.Triangle(i)
             n1, n2, n3 = tri.Get()
-            all_faces.append([
-                n1 - 1 + vertex_offset,
-                n2 - 1 + vertex_offset,
-                n3 - 1 + vertex_offset,
-            ])
+            if is_forward:
+                all_faces.append([
+                    n1 - 1 + vertex_offset,
+                    n2 - 1 + vertex_offset,
+                    n3 - 1 + vertex_offset,
+                ])
+            else:
+                # Swap winding for REVERSED faces
+                all_faces.append([
+                    n1 - 1 + vertex_offset,
+                    n3 - 1 + vertex_offset,
+                    n2 - 1 + vertex_offset,
+                ])
 
         vertex_offset += nb_nodes
         explorer.Next()
@@ -87,10 +103,8 @@ def occ_shape_to_ply(
         f"Tessellation: {len(vertices)} vertices, {len(faces)} triangles"
     )
 
-    # Compute outward-facing vertex normals AND correct face winding.
-    # OCC triangulation produces inconsistent winding across faces (especially
-    # after location transforms). Mitsuba uses face winding for front/back
-    # determination, so both normals AND winding must be consistent.
+    # Compute smooth vertex normals from face normals.
+    # Winding is already corrected during tessellation using OCC face orientation.
     normals, corrected_faces = _compute_outward_normals(vertices, faces, shape)
 
     # Write PLY with corrected faces and normals
@@ -110,72 +124,28 @@ def _compute_outward_normals(
 ) -> Tuple[np.ndarray, np.ndarray]:
     """Compute outward-facing vertex normals and correct face winding.
 
-    1. Compute per-face normals from cross product of triangle edges.
-    2. Determine correct orientation by checking face normals against the
-       shape centroid (outward = away from center).
-    3. Flip triangles with inward normals before accumulating to vertices.
-    4. Average and normalize per-vertex normals.
+    The winding is already corrected during tessellation using OCC's face
+    orientation (TopAbs_FORWARD/REVERSED). This function computes smooth
+    vertex normals by averaging face normals at shared vertices.
 
-    Returns (normals, corrected_faces) so the PLY writer can use consistent
-    winding order — critical for Mitsuba which uses winding for front/back
-    face determination.
+    Returns (normals, corrected_faces) for PLY export.
     """
     n_verts = len(vertices)
     v_normals = np.zeros((n_verts, 3), dtype=np.float64)
 
-    # Compute shape centroid for outward direction reference.
-    # Use OCC bounding box if available, otherwise fall back to vertex bounds.
-    if shape is not None:
-        from OCP.Bnd import Bnd_Box
-        from OCP.BRepBndLib import BRepBndLib
-
-        bbox = Bnd_Box()
-        BRepBndLib.Add_s(shape, bbox)
-        xmin, ymin, zmin, xmax, ymax, zmax = bbox.Get()
-    else:
-        vmin = vertices.min(axis=0).astype(np.float64)
-        vmax = vertices.max(axis=0).astype(np.float64)
-        xmin, ymin, zmin = vmin
-        xmax, ymax, zmax = vmax
-
-    centroid = np.array(
-        [(xmin + xmax) / 2, (ymin + ymax) / 2, (zmin + zmax) / 2],
-        dtype=np.float64,
-    )
-
     # Ensure faces is 2D (numpy creates (3,) for single-face meshes)
     if faces.ndim == 1:
         faces = faces.reshape(1, -1)
 
-    # Compute face normals from triangle geometry
+    # Winding is already correct from tessellation (face orientation check).
+    # Just compute face normals and accumulate to vertices.
     v0 = vertices[faces[:, 0]]
     v1 = vertices[faces[:, 1]]
     v2 = vertices[faces[:, 2]]
 
     edge1 = v1 - v0
     edge2 = v2 - v0
-    face_normals = np.cross(edge1, edge2)
-
-    # Triangle centroids to test direction from shape center
-    tri_centers = (v0 + v1 + v2) / 3.0
-    to_tri = tri_centers - centroid
-
-    # Dot product: positive means normal points away from centroid (outward)
-    dots = np.sum(face_normals * to_tri, axis=1)
-
-    # Faces with negative dot have inward normals — swap columns 1 and 2
-    flip_mask = dots < 0
-    corrected_faces = faces.copy()
-    col1 = corrected_faces[:, 1]
-    col2 = corrected_faces[:, 2]
-    corrected_faces[flip_mask, 1] = col2[flip_mask]
-    corrected_faces[flip_mask, 2] = col1[flip_mask]
-
-    # Recompute face normals after correction
-    v0c = vertices[corrected_faces[:, 0]]
-    v1c = vertices[corrected_faces[:, 1]]
-    v2c = vertices[corrected_faces[:, 2]]
-    fn = np.cross(v1c - v0c, v2c - v0c)
+    fn = np.cross(edge1, edge2)
 
     # Normalize face normals
     lengths = np.linalg.norm(fn, axis=1, keepdims=True)
@@ -183,8 +153,8 @@ def _compute_outward_normals(
     fn /= lengths
 
     # Accumulate to vertices
-    for i in range(len(corrected_faces)):
-        idx = corrected_faces[i]
+    for i in range(len(faces)):
+        idx = faces[i]
         v_normals[idx[0]] += fn[i]
         v_normals[idx[1]] += fn[i]
         v_normals[idx[2]] += fn[i]
@@ -194,7 +164,7 @@ def _compute_outward_normals(
     v_lengths[v_lengths < 1e-10] = 1.0
     v_normals /= v_lengths
 
-    return v_normals.astype(np.float32), corrected_faces.astype(np.uint32)
+    return v_normals.astype(np.float32), faces.astype(np.uint32)
 
 
 def occ_shape_to_stl(