chore: use np.concatenate

app.py

@@ -184,7 +184,10 @@ def generate_mesh(image, source_size=512, render_size=384, mesh_size=512, export
 
     with torch.no_grad():
         planes = model_wrapper.forward(image, source_camera)
-        planes_pil_image = ToPILImage()(planes[0])
+        planes_pil_image = np.concatenate([
+            np.concatenate([planes[1], planes[2]], axis=1),
+            np.concatenate([planes[3], planes[0]], axis=1),
+        ], axis=0)
 
         if export_mesh:
             grid_out = model_wrapper.model.synthesizer.forward_grid(planes=planes, grid_size=mesh_size)