The invisible collision mesh implementation looks correct. The `stage.glb` is loaded, set to `visible: false`, and all child meshes have invisible materials applied. The collision mesh is stored in `this.collisionMesh` for use in collision detection.

**Next Ideas:**
1. **Add Player Collision** - Implement raycasting or Octree-based collision detection using `this.collisionMesh` to prevent the camera/player from passing through walls
2. **First-Person Controls** - Replace OrbitControls with PointerLockControls and add WASD movement with collision response against the stage geometry

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