three-mesh-bvh

A Bounding Volume Hierarchy (BVH) implementation to speed up raycasting and enable spatial queries against three.js meshes.

Casting 500 rays against an 80,000 polygon model at 60fps!

Examples

Raycasting

Skinned geometry

Point cloud intersection

Line intersection

Shape intersection

Geometry edge intersection

SDF generation

WebWorker generation

BVH options inspector

BatchedMesh Raycasting

Tools

Sculpting

Distance comparison

Triangle painting

Lasso selection

Clipped edges

Geometry voxelization

Games

Sphere physics collision

Player movement

Path Tracing

Simple GPU Path Tracing

Lambert GPU Path Tracing

CPU Path Tracing

Gem Refraction Path Tracing

Object Hierarchy BVH

Accelerated Scene Raycasting

Skinned Meshes

Frustum Culling

WebGPU Compute Shaders

Simple Path Tracing

SDF Generation

External Projects

three-gpu-pathtracer

three-bvh-csg

three-edge-projection

Use

Using pre-made functions

import * as THREE from 'three';
import {
	computeBoundsTree, disposeBoundsTree,
	computeBatchedBoundsTree, disposeBatchedBoundsTree, acceleratedRaycast,
} from 'three-mesh-bvh';

// Add the extension functions
THREE.BufferGeometry.prototype.computeBoundsTree = computeBoundsTree;
THREE.BufferGeometry.prototype.disposeBoundsTree = disposeBoundsTree;
THREE.Mesh.prototype.raycast = acceleratedRaycast;

THREE.BatchedMesh.prototype.computeBoundsTree = computeBatchedBoundsTree;
THREE.BatchedMesh.prototype.disposeBoundsTree = disposeBatchedBoundsTree;
THREE.BatchedMesh.prototype.raycast = acceleratedRaycast;

// Generate geometry and associated BVH
const geom = new THREE.TorusKnotGeometry( 10, 3, 400, 100 );
const mesh = new THREE.Mesh( geom, material );
geom.computeBoundsTree();

// Or generate BatchedMesh and associated BVHs
const batchedMesh = new THREE.BatchedMesh( ... );
const geomId = batchedMesh.addGeometry( geom );
const instId = batchedMesh.addGeometry( geom );

// Generate bounds tree for sub geometry
batchedMesh.computeBoundsTree( geomId );

Or manually building the BVH

import * as THREE from 'three';
import { MeshBVH, acceleratedRaycast } from 'three-mesh-bvh';

// Add the raycast function. Assumes the BVH is available on
// the `boundsTree` variable
THREE.Mesh.prototype.raycast = acceleratedRaycast;

// ...

// Generate the BVH and use the newly generated index
geom.boundsTree = new MeshBVH( geom );

And then raycasting

// Setting "firstHitOnly" to true means the Mesh.raycast function will use the
// bvh "raycastFirst" function to return a result more quickly.
const raycaster = new THREE.Raycaster();
raycaster.firstHitOnly = true;
raycaster.intersectObjects( [ mesh ] );

Additional Geometry BVHs

In addition to MeshBVH for triangle meshes, the library provides specialized BVH implementations for other geometry types:

• PointsBVH - For THREE.Points geometries
• LineBVH - For THREE.Line geometries
• LineLoopBVH - For THREE.LineLoop geometries
• LineSegmentsBVH - For THREE.LineSegments geometries

These can be used with the extension functions by passing a type option into "computeBoundsTree" or constructing them explicitly:

This is the beginning of the README. Read the rest at the original. Read the full README ↗