three
Version:
JavaScript 3D library
114 lines (64 loc) • 2.26 kB
JavaScript
import {
BufferGeometry,
Float32BufferAttribute,
LineSegments,
LineBasicMaterial,
Matrix3,
Vector3
} from '../../../build/three.module.js';
var _v1 = new Vector3();
var _v2 = new Vector3();
var _normalMatrix = new Matrix3();
function FaceNormalsHelper( object, size, hex, linewidth ) {
// FaceNormalsHelper only supports THREE.Geometry
this.object = object;
this.size = ( size !== undefined ) ? size : 1;
var color = ( hex !== undefined ) ? hex : 0xffff00;
var width = ( linewidth !== undefined ) ? linewidth : 1;
//
var nNormals = 0;
var objGeometry = this.object.geometry;
if ( objGeometry && objGeometry.isGeometry ) {
nNormals = objGeometry.faces.length;
} else {
console.warn( 'THREE.FaceNormalsHelper: only THREE.Geometry is supported. Use THREE.VertexNormalsHelper, instead.' );
}
//
var geometry = new BufferGeometry();
var positions = new Float32BufferAttribute( nNormals * 2 * 3, 3 );
geometry.setAttribute( 'position', positions );
LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, linewidth: width } ) );
this.type = 'FaceNormalsHelper';
//
this.matrixAutoUpdate = false;
this.update();
}
FaceNormalsHelper.prototype = Object.create( LineSegments.prototype );
FaceNormalsHelper.prototype.constructor = FaceNormalsHelper;
FaceNormalsHelper.prototype.update = function () {
this.object.updateMatrixWorld( true );
_normalMatrix.getNormalMatrix( this.object.matrixWorld );
var matrixWorld = this.object.matrixWorld;
var position = this.geometry.attributes.position;
//
var objGeometry = this.object.geometry;
var vertices = objGeometry.vertices;
var faces = objGeometry.faces;
var idx = 0;
for ( var i = 0, l = faces.length; i < l; i ++ ) {
var face = faces[ i ];
var normal = face.normal;
_v1.copy( vertices[ face.a ] )
.add( vertices[ face.b ] )
.add( vertices[ face.c ] )
.divideScalar( 3 )
.applyMatrix4( matrixWorld );
_v2.copy( normal ).applyMatrix3( _normalMatrix ).normalize().multiplyScalar( this.size ).add( _v1 );
position.setXYZ( idx, _v1.x, _v1.y, _v1.z );
idx = idx + 1;
position.setXYZ( idx, _v2.x, _v2.y, _v2.z );
idx = idx + 1;
}
position.needsUpdate = true;
};
export { FaceNormalsHelper };