Geometry.fromBufferGeometry: avoid allocating tempNormals, tempUVs and tempUVs2 vectors

src/core/Geometry.js

@@ -228,19 +228,9 @@ Geometry.prototype = Object.assign( Object.create( EventDispatcher.prototype ),
 
 		if ( uvs2 !== undefined ) this.faceVertexUvs[ 1 ] = [];
 
-		var tempNormals = [];
-		var tempUVs = [];
-		var tempUVs2 = [];
-
 		for ( var i = 0, j = 0; i < positions.length; i += 3, j += 2 ) {
 
-			scope.vertices.push( new Vector3( positions[ i ], positions[ i + 1 ], positions[ i + 2 ] ) );
-
-			if ( normals !== undefined ) {
-
-				tempNormals.push( new Vector3( normals[ i ], normals[ i + 1 ], normals[ i + 2 ] ) );
-
-			}
+			scope.vertices.push( new Vector3().fromArray( positions, i ) );
 
 			if ( colors !== undefined ) {
 
@@ -248,38 +238,39 @@ Geometry.prototype = Object.assign( Object.create( EventDispatcher.prototype ),
 
 			}
 
-			if ( uvs !== undefined ) {
-
-				tempUVs.push( new Vector2( uvs[ j ], uvs[ j + 1 ] ) );
-
-			}
-
-			if ( uvs2 !== undefined ) {
-
-				tempUVs2.push( new Vector2( uvs2[ j ], uvs2[ j + 1 ] ) );
-
-			}
-
 		}
 
 		function addFace( a, b, c, materialIndex ) {
 
-			var vertexNormals = normals !== undefined ? [ tempNormals[ a ].clone(), tempNormals[ b ].clone(), tempNormals[ c ].clone() ] : [];
 			var vertexColors = colors !== undefined ? [ scope.colors[ a ].clone(), scope.colors[ b ].clone(), scope.colors[ c ].clone() ] : [];
 
+			var vertexNormals = normals === undefined ? [] : [
+				new Vector3().fromArray( normals, a * 3 ),
+				new Vector3().fromArray( normals, b * 3 ),
+				new Vector3().fromArray( normals, c * 3 )
+			];
+
 			var face = new Face3( a, b, c, vertexNormals, vertexColors, materialIndex );
 
 			scope.faces.push( face );
 
 			if ( uvs !== undefined ) {
 
-				scope.faceVertexUvs[ 0 ].push( [ tempUVs[ a ].clone(), tempUVs[ b ].clone(), tempUVs[ c ].clone() ] );
+				scope.faceVertexUvs[ 0 ].push( [
+					new Vector2().fromArray( uvs, a * 2 ),
+					new Vector2().fromArray( uvs, b * 2 ),
+					new Vector2().fromArray( uvs, c * 2 )
+				] );
 
 			}
 
 			if ( uvs2 !== undefined ) {
 
-				scope.faceVertexUvs[ 1 ].push( [ tempUVs2[ a ].clone(), tempUVs2[ b ].clone(), tempUVs2[ c ].clone() ] );
+				scope.faceVertexUvs[ 1 ].push( [
+					new Vector2().fromArray( uvs2, a * 2 ),
+					new Vector2().fromArray( uvs2, b * 2 ),
+					new Vector2().fromArray( uvs2, c * 2 )
+				] );
 
 			}