Merge pull request #17991 from WestLangley/dev_tangents_helper

Added VertexTangentsHelper

src/Three.js

@@ -131,6 +131,7 @@ export { Color } from './math/Color.js';
 export { SphericalHarmonics3 } from './math/SphericalHarmonics3.js';
 export { ImmediateRenderObject } from './extras/objects/ImmediateRenderObject.js';
 export { VertexNormalsHelper } from './helpers/VertexNormalsHelper.js';
+export { VertexTangentsHelper } from './helpers/VertexTangentsHelper.js';
 export { SpotLightHelper } from './helpers/SpotLightHelper.js';
 export { SkeletonHelper } from './helpers/SkeletonHelper.js';
 export { PointLightHelper } from './helpers/PointLightHelper.js';

src/helpers/VertexNormalsHelper.d.ts

@@ -13,6 +13,6 @@ export class VertexNormalsHelper extends LineSegments {
 	object: Object3D;
 	size: number;
 
-	update( object?: Object3D ): void;
+	update(): void;
 
 }

src/helpers/VertexTangentsHelper.d.ts

@@ -0,0 +1,18 @@
+import { Object3D } from './../core/Object3D';
+import { LineSegments } from './../objects/LineSegments';
+
+export class VertexTangentsHelper extends LineSegments {
+
+	constructor(
+		object: Object3D,
+		size?: number,
+		hex?: number,
+		linewidth?: number
+	);
+
+	object: Object3D;
+	size: number;
+
+	update(): void;
+
+}

src/helpers/VertexTangentsHelper.js

@@ -0,0 +1,100 @@
+/**
+ * @author WestLangley / http://github.com/WestLangley
+ */
+
+import { Vector3 } from '../math/Vector3.js';
+import { LineSegments } from '../objects/LineSegments.js';
+import { LineBasicMaterial } from '../materials/LineBasicMaterial.js';
+import { Float32BufferAttribute } from '../core/BufferAttribute.js';
+import { BufferGeometry } from '../core/BufferGeometry.js';
+
+var _v1 = new Vector3();
+var _v2 = new Vector3();
+
+function VertexTangentsHelper( object, size, hex, linewidth ) {
+
+	this.object = object;
+
+	this.size = ( size !== undefined ) ? size : 1;
+
+	var color = ( hex !== undefined ) ? hex : 0x00ffff;
+
+	var width = ( linewidth !== undefined ) ? linewidth : 1;
+
+	//
+
+	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, linewidth: width } ) );
+
+	//
+
+	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 };