Three CSG

CSG (Constructive Solid Geometry) library for three.js with Typescript support.

This is a typescript rewrite of THREE-CSGMesh.

Concept

CSG is the name of a technique for generating a new geometry as a function of two input geometries.

CSG is sometimes referred to as "Boolean" operators in 3d modelling packages.

Internally it uses a structure called a BSP (binary space partitioning) tree to carry out these operations.

The supported operations are .subtract, .union, and .intersect.

By using different combinations of these 3 operations, and changing the order of the input models, you can construct any combination of the input models.

Installation

• Install with npm npm i -save @hi-level/three-csg
• Install with yarn yarn add @hi-level/three-csg

Example usage

import * as THREE from 'three';
import { CSG } from '@hi-level/three-csg';

// Make 2 box meshes..
const meshA = new THREE.Mesh(new THREE.BoxGeometry(1,1,1));
const meshB = new THREE.Mesh(new THREE.BoxGeometry(1,1,1));

// Offset one of the boxes by half its width..
meshB.position.add(new THREE.Vector3(0.5, 0.5, 0.5);

// Make sure the .matrix of each mesh is current
meshA.updateMatrix();
meshB.updateMatrix();

// Create a bsp tree from each of the meshes
const bspA = CSG.fromMesh(meshA);                        
const bspB = CSG.fromMesh(meshB);

// Subtract one bsp from the other via .subtract... other supported modes are .union and .intersect
const bspResult = bspA.subtract(bspB);

// Get the resulting mesh from the result bsp
const meshResult = CSG.toMesh(bspResult, meshA.matrix);

// Set the results material to the material of the first cube.
meshResult.material = meshA.material;