Update app.py

app.py

@@ -109,7 +109,10 @@ infer_config = config.infer_config
 
 IS_FLEXICUBES = True if config_name.startswith('instant-mesh') else False
 
-device = torch.device('cuda')
+# pick GPU if available, else CPU
+device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
+if device.type == 'cpu':
+    print("⚠️  No CUDA GPU detected. Falling back to CPU (this will be very slow!)")
 
 # load diffusion model
 print('Loading diffusion model ...')