Advanced Usage of Three-Mesh-BVH: Customizing Your BVH for Optimal Performance

Overview

three-mesh-bvh is not just about simple acceleration—it offers a variety of customization options to fine-tune the BVH structure to your needs. Whether you’re dealing with specific geometries, optimizing for different devices, or needing a balance between speed and memory usage, three-mesh-bvh provides the tools you need.

Key Customization Options:

• Max Leaf Tris: This parameter controls the maximum number of triangles allowed in a leaf node. Lower values increase raycasting speed but also increase memory usage and build time.
• Strategy: three-mesh-bvh offers different strategies for splitting nodes, such as SAH (Surface Area Heuristic) and CENTER. The SAH strategy generally provides the best performance but is more computationally expensive to build.
• Lazy Construction: You can delay the construction of the BVH until it’s actually needed, which can be beneficial in dynamic scenes where geometry changes frequently.

Practical Example:

import { MeshBVH, MeshBVHHelper, CENTER, SAH } from 'three-mesh-bvh';

// Create geometry and mesh
const geometry = new BoxGeometry(1, 1, 1);
const mesh = new Mesh(geometry, new MeshStandardMaterial());

// Customize BVH
geometry.boundsTree = new MeshBVH(geometry, {
  strategy: SAH,
  maxLeafTris: 10
});

Optimizing for Different Scenarios:

• Dynamic Scenes: If your scene changes frequently, consider using a higher maxLeafTris value and CENTER strategy to reduce rebuild times.
• Static Large Scenes: For large, static scenes, the SAH strategy with a low maxLeafTris value provides the best raycasting performance.

Conclusion: three-mesh-bvh allows developers to fine-tune the BVH structure for various scenarios. By understanding and applying these customizations, you can achieve the optimal balance between performance and resource usage for your specific application needs.