Update src/pixel3dmm/tracking/tracker.py

src/pixel3dmm/tracking/tracker.py

@@ -1296,7 +1296,26 @@ class Tracker(object):
                 # `vertices` is your posed mesh: shape (1, V, 3)
                 verts_np  = vertices[0].detach().cpu().numpy()
 
-                trimesh.Trimesh(faces=faces_np, vertices=verts_np, process=False).export(ply_path)
+                # 1) build your mesh (this will compute smooth normals automatically)
+                mesh = trimesh.Trimesh(vertices=verts_np, faces=faces_np)
+
+                # 2) fetch those normals: shape is (V,3), each component in [-1,1]
+                normals = mesh.vertex_normals  # (V,3) numpy array
+
+                # 3) convert them to RGB in [0,255]: 
+                #    (n+1)/2 maps [-1,1]→[0,1], then *255→[0,255]
+                colors = ((normals + 1.0) * 0.5 * 255.0).astype(np.uint8)  # (V,3)
+
+                # 4) you need RGBA for many formats—just set alpha=255
+                alpha = np.full((colors.shape[0],1), 255, dtype=np.uint8)
+                vertex_colors = np.hstack([colors, alpha])               # (V,4)
+
+                # 5) assign those as your mesh’s visual colors
+                mesh.visual.vertex_colors = vertex_colors
+
+                # 6) export—PLY or GLB both support vertex colors
+                out_path = os.path.join(self.mesh_folder, f"{frame_id}.glb")
+                mesh.export(out_path)
 
             return arr