Accueil / npm / three@0.186.1 / examples / jsm / geometries / ConvexGeometry.js
ConvexGeometry.js
import {
BufferGeometry,
Float32BufferAttribute
} from 'three';
import { ConvexHull } from '../math/ConvexHull.js';
/**
* This class can be used to generate a convex hull for a given array of 3D points.
* The average time complexity for this task is considered to be O(nlog(n)).
*
* ```js
* const geometry = new ConvexGeometry( points );
* const material = new THREE.MeshBasicMaterial( { color: 0x00ff00 } );
* const mesh = new THREE.Mesh( geometry, material );
* scene.add( mesh );
* ```
*
* @augments BufferGeometry
* @three_import import { ConvexGeometry } from 'three/addons/geometries/ConvexGeometry.js';
*/
class ConvexGeometry extends BufferGeometry {
/**
* Constructs a new convex geometry.
*
* @param {Array<Vector3>} points - An array of points in 3D space which should be enclosed by the convex hull.
*/
constructor( points = [] ) {
super();
// buffers
const vertices = [];
const normals = [];
const convexHull = new ConvexHull().setFromPoints( points );
// generate vertices and normals
const faces = convexHull.faces;
for ( let i = 0; i < faces.length; i ++ ) {
const face = faces[ i ];
let edge = face.edge;
// we move along a doubly-connected edge list to access all face points (see HalfEdge docs)
do {
const point = edge.head().point;
vertices.push( point.x, point.y, point.z );
normals.push( face.normal.x, face.normal.y, face.normal.z );
edge = edge.next;
} while ( edge !== face.edge );
}
// build geometry
this.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
this.setAttribute( 'normal', new Float32BufferAttribute( normals, 3 ) );
}
}
export { ConvexGeometry };