https://github.com/WWBN/AVideo/issues/8713

node_modules/three/examples/jsm/helpers/VertexNormalsHelper.js

@@ -0,0 +1,116 @@
+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 VertexNormalsHelper( object, size, hex ) {
+
+	this.object = object;
+
+	this.size = ( size !== undefined ) ? size : 0.1;
+
+	var color = ( hex !== undefined ) ? hex : 0xff0000;
+
+	//
+
+	var nNormals = 0;
+
+	var objGeometry = this.object.geometry;
+
+	if ( objGeometry && objGeometry.isGeometry ) {
+
+		console.error( 'THREE.VertexNormalsHelper no longer supports Geometry. Use BufferGeometry instead.' );
+		return;
+
+	} else if ( objGeometry && objGeometry.isBufferGeometry ) {
+
+		nNormals = objGeometry.attributes.normal.count;
+
+	}
+
+	//
+
+	var geometry = new BufferGeometry();
+
+	var positions = new Float32BufferAttribute( nNormals * 2 * 3, 3 );
+
+	geometry.setAttribute( 'position', positions );
+
+	LineSegments.call( this, geometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );
+
+	this.type = 'VertexNormalsHelper';
+
+	//
+
+	this.matrixAutoUpdate = false;
+
+	this.update();
+
+}
+
+VertexNormalsHelper.prototype = Object.create( LineSegments.prototype );
+VertexNormalsHelper.prototype.constructor = VertexNormalsHelper;
+
+VertexNormalsHelper.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;
+
+	if ( objGeometry && objGeometry.isGeometry ) {
+
+		console.error( 'THREE.VertexNormalsHelper no longer supports Geometry. Use BufferGeometry instead.' );
+		return;
+
+	} else if ( objGeometry && objGeometry.isBufferGeometry ) {
+
+		var objPos = objGeometry.attributes.position;
+
+		var objNorm = objGeometry.attributes.normal;
+
+		var idx = 0;
+
+		// for simplicity, ignore index and drawcalls, and render every normal
+
+		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( objNorm.getX( j ), objNorm.getY( j ), objNorm.getZ( j ) );
+
+			_v2.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 { VertexNormalsHelper };