Three.js Models Missing in Production Build with Vite

This issue where Three.js models appear in development but disappear in production is likely related to how Vite handles asset loading and paths in production builds. Here are some potential causes and solutions:

Possible Causes

1. Asset Path Resolution: Vite handles asset paths differently between development and production. In production, assets are typically hashed and moved to a different directory.

2. Node.js Environment Differences: As mentioned in the Three.js documentation, Three.js is designed for web environments and relies on browser objects and DOM APIs that don't exist in Node.js environments.

Potential Solutions

1. Check Asset Loading Paths

Make sure your model loading code uses relative paths that will work in both development and production:

JAVASCRIPTCopied
// Instead of this:
loader.load('/models/mymodel.gltf', ...);

// Try this:
import modelUrl from '../assets/models/mymodel.gltf?url';
loader.load(modelUrl, ...);

2. Use Vite's Asset Handling

Vite has specific ways to handle assets. Try using the ?url suffix for imports:

JAVASCRIPTCopied
import modelPath from './path/to/model.gltf?url';

3. Configure Public Directory

Make sure your models are in the public directory if you're using absolute paths:

JAVASCRIPTCopied
// vite.config.js
export default {
  publicDir: 'public',
  // ...
}

4. Check for Loaders

Ensure that any Three.js loaders (like GLTFLoader, OBJLoader, etc.) are properly imported and initialized in your production build:

JAVASCRIPTCopied
import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader.js';

5. Debug with Network Monitoring

In your production preview, open the browser's developer tools and check the Network tab to see if there are any 404 errors for model files.

6. Add Explicit File Extensions

Vite might handle file extensions differently in production. Try specifying the full extension:

JAVASCRIPTCopied
loader.load('./models/model.gltf', ...);

7. Check Vite Configuration

Make sure your Vite configuration properly handles the file types you're using:

JAVASCRIPTCopied
// vite.config.js
export default {
  assetsInclude: ['**/*.gltf', '**/*.glb', '**/*.obj'],
  // ...
}

If you're still facing issues, consider adding more detailed logging to your model loading code to help identify exactly where the problem occurs in the production build.