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- 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 };
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