Update vertex color assignment in generate3d function to utilize original colors

- Modified mesh creation to set vertex colors to orig_colors, enhancing the visual fidelity of the generated mesh.
- Removed previous reliance on nearest neighbor color mapping, streamlining the color assignment process.

inference.py

@@ -90,7 +90,7 @@ def generate3d(model, rgb, ccm, device):
     # new_colors = orig_colors[idxs[:, 0]]
 
     # Create the new mesh with colors
-    mesh = trimesh.Trimesh(vertices=verts, faces=faces, vertex_colors=None)
+    mesh = trimesh.Trimesh(vertices=verts, faces=faces, vertex_colors=orig_colors)
 
     # === Export OBJ/MTL/PNG ===
     obj_path = tempfile.NamedTemporaryFile(suffix=".obj", delete=False).name