Update app.py

app.py

@@ -9,7 +9,7 @@ def apply_masked_visuals(section):
     mesh = trimesh.load('train.glb', force='mesh')
     im = Image.open('rust_steel.png').convert('RGB')
 
-    # Calculate bounding box coordinates
+    # Calculate the bounding box coordinates
     bounds = mesh.bounds
     min_bounds, max_bounds = bounds[0], bounds[1]
     mid_x = (max_bounds[0] + min_bounds[0]) / 2
@@ -30,17 +30,15 @@ def apply_masked_visuals(section):
     # Select the indices for the specified section
     selected_indices = sections[section]
 
-    # Check if the mesh has existing visuals
-    if mesh.visual.kind == 'texture':
-        visual = mesh.visual.copy()
-        visual.update_vertices(mask=np.isin(range(len(mesh.vertices)), selected_indices))
-    else:
-        visual = trimesh.visual.ColorVisuals(vertex_colors=np.ones((len(mesh.vertices), 4)) * 255)
+    # Ensure that all indices are valid
+    valid_indices = selected_indices[selected_indices < len(mesh.vertices)]
 
-    # Prepare the new visual properties (UV or color updates)
-    uv = np.copy(visual.uv) if visual.kind == 'texture' else np.random.rand(len(mesh.vertices), 2)
+    # Create or re-initialize the UV array
+    uv = np.random.rand(len(mesh.vertices), 2)
+
+    # Generate new UV coordinates only for the selected section
     new_uv = np.copy(uv)
-    new_uv[selected_indices, :] = np.random.rand(len(selected_indices), 2)
+    new_uv[valid_indices, :] = np.random.rand(len(valid_indices), 2)
 
     # Create a new material with the image texture
     material = trimesh.visual.texture.SimpleMaterial(image=im)