- Improved sketching

drawing_modules/vtk_widget.py

@@ -282,21 +282,57 @@ class VTKWidget(QtWidgets.QWidget):
     def render_from_points_direct_with_faces(self, vertices, faces, color=(0.1, 0.2, 0.8), line_width=2, point_size=5):
         """Sketch Widget has inverted Y axiis therefore we invert y via scale here until fix"""
 
+        # Handle empty vertices or faces
+        if len(vertices) == 0 or len(faces) == 0:
+            print("Warning: No vertices or faces to render")
+            return
+
         points = vtk.vtkPoints()
 
-        # Use SetData with numpy array
-        vtk_array = numpy_to_vtk(vertices, deep=True)
-        points.SetData(vtk_array)
+        # Validate vertices shape
+        if vertices.ndim != 2 or vertices.shape[1] != 3:
+            print(f"Warning: Invalid vertex shape {vertices.shape}. Expected Nx3.")
+            return
+
+        # Validate faces shape
+        if faces.ndim != 2 or faces.shape[1] != 3:
+            print(f"Warning: Invalid face shape {faces.shape}. Expected Nx3.")
+            return
+
+        # Use SetData with numpy array - ensure vertices are float32
+        try:
+            vertices_float = np.asarray(vertices, dtype=np.float32)
+            vtk_array = numpy_to_vtk(vertices_float, deep=True)
+            points.SetData(vtk_array)
+        except Exception as e:
+            print(f"Error converting vertices to VTK array: {e}")
+            # Fallback: manually insert points
+            for vertex in vertices:
+                points.InsertNextPoint(vertex[0], vertex[1], vertex[2])
 
         # Create a vtkCellArray to store the triangles
         triangles = vtk.vtkCellArray()
-        for face in faces:
+        num_vertices = len(vertices)
+        
+        for i, face in enumerate(faces):
+            # Validate face indices
+            if (face[0] >= num_vertices or face[0] < 0 or 
+                face[1] >= num_vertices or face[1] < 0 or 
+                face[2] >= num_vertices or face[2] < 0):
+                print(f"Warning: Invalid face indices {face} at index {i}. Skipping face.")
+                continue
+                
             triangle = vtk.vtkTriangle()
-            triangle.GetPointIds().SetId(0, face[0])
-            triangle.GetPointIds().SetId(1, face[1])
-            triangle.GetPointIds().SetId(2, face[2])
+            triangle.GetPointIds().SetId(0, int(face[0]))
+            triangle.GetPointIds().SetId(1, int(face[1]))
+            triangle.GetPointIds().SetId(2, int(face[2]))
             triangles.InsertNextCell(triangle)
 
+        # Check if we have any valid triangles
+        if triangles.GetNumberOfCells() == 0:
+            print("Warning: No valid triangles to render")
+            return
+
         # Create a polydata object
         polydata = vtk.vtkPolyData()
         polydata.SetPoints(points)
@@ -309,7 +345,17 @@ class VTKWidget(QtWidgets.QWidget):
         normalGenerator.ComputeCellNormalsOn()
         normalGenerator.Update()
 
-        self.cell_normals = vtk_to_numpy(normalGenerator.GetOutput().GetCellData().GetNormals())
+        # Safely get cell normals, with fallback if they're not available
+        cell_normals = normalGenerator.GetOutput().GetCellData().GetNormals()
+        if cell_normals:
+            try:
+                self.cell_normals = vtk_to_numpy(cell_normals)
+            except Exception as e:
+                print(f"Warning: Could not convert cell normals to numpy array: {e}")
+                self.cell_normals = None
+        else:
+            print("Warning: No cell normals available")
+            self.cell_normals = None
 
         # Create a mapper and actor
         mapper = vtk.vtkPolyDataMapper()