# COLMAP Installation Fix for Hugging Face Spaces

## Problem
COLMAP cannot be installed via pip - it's a system-level dependency.

## Solution

### Files to Upload to Your Hugging Face Space:

1. **requirements.txt** - Updated (removed colmap)
2. **packages.txt** - NEW FILE (installs COLMAP via apt-get)
3. **app-10.py** - Your existing app (no changes needed)

### Steps to Fix:

1. In your Hugging Face Space repository, replace the old `requirements.txt` with the new one
2. Add the new `packages.txt` file to the root directory of your Space
3. Commit the changes

### What These Files Do:

- **requirements.txt**: Installs Python packages via pip
  - Removed: `colmap` (not a Python package!)
  
- **packages.txt**: Installs system packages via apt-get
  - Added: `colmap` (system dependency)

## Build Time Warning

Installing COLMAP will increase your Space's build time by 1-3 minutes. This is normal.

## GPU Requirements

Your app uses:
- COLMAP (GPU-accelerated feature extraction)
- NeRF training (requires GPU)

Make sure your Space is set to use GPU hardware:
1. Go to Space Settings
2. Select "GPU" under Hardware
3. Choose an appropriate GPU tier (T4 or better recommended)

## Testing COLMAP Installation

After the Space builds successfully, you can verify COLMAP is installed by checking the logs. Your app already has a check at line 94:

```python
result = subprocess.run(["which", "colmap"], capture_output=True, text=True)
if result.returncode != 0:
    return {"status": "colmap_not_found", "message": "COLMAP not installed"}
```

## Alternative: Custom Dockerfile

If `packages.txt` doesn't work for some reason, you can use a custom Dockerfile instead. Let me know if you need help with that approach.

## Troubleshooting

### If COLMAP still not found:
- Check the build logs for apt-get errors
- Verify `packages.txt` is in the root directory
- Make sure there are no extra spaces in packages.txt

### If nerfstudio doesn't work:
You may need to add additional system dependencies to packages.txt:
```
colmap
libgl1-mesa-glx
libglib2.0-0
```

### Memory Issues:
NeRF training is memory-intensive. If you get OOM errors:
- Reduce `max_frames_slider` default (try 50 instead of 100)
- Reduce `iterations_slider` default (try 1000 instead of 2000)
- Use a larger GPU tier in Space settings

## Expected Build Output

After fixing, your build should show:
```
--> RUN apt-get update && apt-get install -y colmap ...
✓ Successfully installed colmap
--> RUN pip install --no-cache-dir -r requirements.txt
✓ Successfully installed gradio opencv-python-headless numpy Pillow nerfstudio torch torchvision
```

## Questions?

If you continue having issues, check:
1. Are both files in the root directory?
2. Is packages.txt correctly formatted (just "colmap" on one line)?
3. Did you commit and push the changes?