To speed up collision for high-poly 3D models, use a simplified low-poly proxy collision mesh instead of the original high-poly geometry.
A proxy collision mesh retains the model’s basic shape but has far fewer polygons, reducing the computational load for collision detection—critical for real-time apps like games or VR where performance matters most.
In tools like Blender or Unity, generate a proxy by decimating the high-poly mesh (lowering polygons while preserving form) or using automatic retopology, then assign it as the collision shape in your engine.