three
Version:
JavaScript 3D library
99 lines (54 loc) • 2.09 kB
JavaScript
import {
BufferGeometry,
Float32BufferAttribute,
LineSegments,
LineBasicMaterial,
Vector3
} from '../../../build/three.module.js';
var _v1 = new Vector3();
var _v2 = new Vector3();
function VertexTangentsHelper( object, size, hex ) {
this.object = object;
this.size = ( size !== undefined ) ? size : 1;
var color = ( hex !== undefined ) ? hex : 0x00ffff;
//
var objGeometry = this.object.geometry;
if ( ! ( objGeometry && objGeometry.isBufferGeometry ) ) {
console.error( 'THREE.VertexTangentsHelper: geometry not an instance of THREE.BufferGeometry.', objGeometry );
return;
}
var nTangents = objGeometry.attributes.tangent.count;
//
var geometry = new BufferGeometry();
var positions = new Float32BufferAttribute( nTangents * 2 * 3, 3 );
geometry.setAttribute( 'position', positions );
LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );
this.type = 'VertexTangentsHelper';
//
this.matrixAutoUpdate = false;
this.update();
}
VertexTangentsHelper.prototype = Object.create( LineSegments.prototype );
VertexTangentsHelper.prototype.constructor = VertexTangentsHelper;
VertexTangentsHelper.prototype.update = function () {
this.object.updateMatrixWorld( true );
var matrixWorld = this.object.matrixWorld;
var position = this.geometry.attributes.position;
//
var objGeometry = this.object.geometry;
var objPos = objGeometry.attributes.position;
var objTan = objGeometry.attributes.tangent;
var idx = 0;
// for simplicity, ignore index and drawcalls, and render every tangent
for ( var j = 0, jl = objPos.count; j < jl; j ++ ) {
_v1.set( objPos.getX( j ), objPos.getY( j ), objPos.getZ( j ) ).applyMatrix4( matrixWorld );
_v2.set( objTan.getX( j ), objTan.getY( j ), objTan.getZ( j ) );
_v2.transformDirection( matrixWorld ).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 { VertexTangentsHelper };