最新代码

public/sdk/three/jsm/helpers/VertexTangentsHelper.js

@@ -0,0 +1,88 @@
+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 };