89 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
		
		
			
		
	
	
			89 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
|  | import { | ||
|  | 	BufferGeometry, | ||
|  | 	Float32BufferAttribute, | ||
|  | 	LineSegments, | ||
|  | 	LineBasicMaterial, | ||
|  | 	Vector3 | ||
|  | } from 'three'; | ||
|  | 
 | ||
|  | const _v1 = new Vector3(); | ||
|  | const _v2 = new Vector3(); | ||
|  | 
 | ||
|  | class VertexTangentsHelper extends LineSegments { | ||
|  | 
 | ||
|  | 	constructor( object, size = 1, color = 0x00ffff ) { | ||
|  | 
 | ||
|  | 		const geometry = new BufferGeometry(); | ||
|  | 
 | ||
|  | 		const nTangents = object.geometry.attributes.tangent.count; | ||
|  | 		const positions = new Float32BufferAttribute( nTangents * 2 * 3, 3 ); | ||
|  | 
 | ||
|  | 		geometry.setAttribute( 'position', positions ); | ||
|  | 
 | ||
|  | 		super( geometry, new LineBasicMaterial( { color, toneMapped: false } ) ); | ||
|  | 
 | ||
|  | 		this.object = object; | ||
|  | 		this.size = size; | ||
|  | 		this.type = 'VertexTangentsHelper'; | ||
|  | 
 | ||
|  | 		//
 | ||
|  | 
 | ||
|  | 		this.matrixAutoUpdate = false; | ||
|  | 
 | ||
|  | 		this.update(); | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | 	update() { | ||
|  | 
 | ||
|  | 		this.object.updateMatrixWorld( true ); | ||
|  | 
 | ||
|  | 		const matrixWorld = this.object.matrixWorld; | ||
|  | 
 | ||
|  | 		const position = this.geometry.attributes.position; | ||
|  | 
 | ||
|  | 		//
 | ||
|  | 
 | ||
|  | 		const objGeometry = this.object.geometry; | ||
|  | 
 | ||
|  | 		const objPos = objGeometry.attributes.position; | ||
|  | 
 | ||
|  | 		const objTan = objGeometry.attributes.tangent; | ||
|  | 
 | ||
|  | 		let idx = 0; | ||
|  | 
 | ||
|  | 		// for simplicity, ignore index and drawcalls, and render every tangent
 | ||
|  | 
 | ||
|  | 		for ( let j = 0, jl = objPos.count; j < jl; j ++ ) { | ||
|  | 
 | ||
|  | 			_v1.fromBufferAttribute( objPos, j ).applyMatrix4( matrixWorld ); | ||
|  | 
 | ||
|  | 			_v2.fromBufferAttribute( objTan, 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; | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | 	dispose() { | ||
|  | 
 | ||
|  | 		this.geometry.dispose(); | ||
|  | 		this.material.dispose(); | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | } | ||
|  | 
 | ||
|  | export { VertexTangentsHelper }; |