Add automatic weight download

model.py

@@ -1,11 +1,31 @@
 import torch
 import logging
+import os
+from pathlib import Path
 from dust3r.model import AsymmetricCroCo3DStereo
 
 logger = logging.getLogger(__name__)
 
 
+def download_weights(model_path: str):
+    """Download model weights if they don't exist"""
+    if os.path.exists(model_path):
+        logger.info(f"Weights already exist at {model_path}")
+        return
+    
+    logger.info("Weights not found. Downloading...")
+    Path(model_path).parent.mkdir(parents=True, exist_ok=True)
+    
+    import urllib.request
+    url = "https://huggingface.co/camenduru/dust3r/resolve/main/DUSt3R_ViTLarge_BaseDecoder_512_dpt.pth"
+    
+    logger.info(f"Downloading from {url}")
+    urllib.request.urlretrieve(url, model_path)
+    logger.info("Download complete!")
+
+
 def initialize(model_path: str, device: str) -> torch.nn.Module:
+    download_weights(model_path)
     logger.info(f"Loading model from: {model_path}")
     
     logger.info("Loading checkpoint...")