Avoid unneeded geometry allocations.

src/helpers/ArrowHelper.js

@@ -24,11 +24,7 @@ import { Mesh } from '../objects/Mesh';
 import { Line } from '../objects/Line';
 import { Vector3 } from '../math/Vector3';
 
-var lineGeometry = new BufferGeometry();
-lineGeometry.addAttribute( 'position', new Float32BufferAttribute( [ 0, 0, 0, 0, 1, 0 ], 3 ) );
-
-var coneGeometry = new CylinderBufferGeometry( 0, 0.5, 1, 5, 1 );
-coneGeometry.translate( 0, - 0.5, 0 );
+var lineGeometry, coneGeometry;
 
 function ArrowHelper( dir, origin, length, color, headLength, headWidth ) {
 
@@ -41,6 +37,16 @@ function ArrowHelper( dir, origin, length, color, headLength, headWidth ) {
 	if ( headLength === undefined ) headLength = 0.2 * length;
 	if ( headWidth === undefined ) headWidth = 0.2 * headLength;
 
+	if ( lineGeometry === undefined ) {
+
+		lineGeometry = new BufferGeometry();
+		lineGeometry.addAttribute( 'position', new Float32BufferAttribute( [ 0, 0, 0, 0, 1, 0 ], 3 ) );
+
+		coneGeometry = new CylinderBufferGeometry( 0, 0.5, 1, 5, 1 );
+		coneGeometry.translate( 0, - 0.5, 0 );
+
+	}
+
 	this.position.copy( origin );
 
 	this.line = new Line( lineGeometry, new LineBasicMaterial( { color: color } ) );

src/renderers/WebGLRenderer.js

@@ -297,25 +297,8 @@ function WebGLRenderer( parameters ) {
 
 	//
 
-	var backgroundCamera = new OrthographicCamera( - 1, 1, 1, - 1, 0, 1 );
-	var backgroundCamera2 = new PerspectiveCamera();
-	var backgroundPlaneMesh = new Mesh(
-		new PlaneBufferGeometry( 2, 2 ),
-		new MeshBasicMaterial( { depthTest: false, depthWrite: false, fog: false } )
-	);
-	var backgroundBoxShader = ShaderLib[ 'cube' ];
-	var backgroundBoxMesh = new Mesh(
-		new BoxBufferGeometry( 5, 5, 5 ),
-		new ShaderMaterial( {
-			uniforms: backgroundBoxShader.uniforms,
-			vertexShader: backgroundBoxShader.vertexShader,
-			fragmentShader: backgroundBoxShader.fragmentShader,
-			side: BackSide,
-			depthTest: false,
-			depthWrite: false,
-			fog: false
-		} )
-	);
+	var backgroundPlaneCamera, backgroundPlaneMesh;
+	var backgroundBoxCamera, backgroundBoxMesh;
 
 	//
 
@@ -1186,25 +1169,56 @@ function WebGLRenderer( parameters ) {
 
 		if ( background && background.isCubeTexture ) {
 
-			backgroundCamera2.projectionMatrix.copy( camera.projectionMatrix );
+			if ( backgroundBoxCamera === undefined ) {
+
+				backgroundBoxCamera = new PerspectiveCamera();
+
+				backgroundBoxMesh = new Mesh(
+					new BoxBufferGeometry( 5, 5, 5 ),
+					new ShaderMaterial( {
+						uniforms: ShaderLib.cube.uniforms,
+						vertexShader: ShaderLib.cube.vertexShader,
+						fragmentShader: ShaderLib.cube.fragmentShader,
+						side: BackSide,
+						depthTest: false,
+						depthWrite: false,
+						fog: false
+					} )
+				);
+
+			}
+
+			backgroundBoxCamera.projectionMatrix.copy( camera.projectionMatrix );
+
+			backgroundBoxCamera.matrixWorld.extractRotation( camera.matrixWorld );
+			backgroundBoxCamera.matrixWorldInverse.getInverse( backgroundBoxCamera.matrixWorld );
 
-			backgroundCamera2.matrixWorld.extractRotation( camera.matrixWorld );
-			backgroundCamera2.matrixWorldInverse.getInverse( backgroundCamera2.matrixWorld );
 
 			backgroundBoxMesh.material.uniforms[ "tCube" ].value = background;
-			backgroundBoxMesh.modelViewMatrix.multiplyMatrices( backgroundCamera2.matrixWorldInverse, backgroundBoxMesh.matrixWorld );
+			backgroundBoxMesh.modelViewMatrix.multiplyMatrices( backgroundBoxCamera.matrixWorldInverse, backgroundBoxMesh.matrixWorld );
 
 			objects.update( backgroundBoxMesh );
 
-			_this.renderBufferDirect( backgroundCamera2, null, backgroundBoxMesh.geometry, backgroundBoxMesh.material, backgroundBoxMesh, null );
+			_this.renderBufferDirect( backgroundBoxCamera, null, backgroundBoxMesh.geometry, backgroundBoxMesh.material, backgroundBoxMesh, null );
 
 		} else if ( background && background.isTexture ) {
 
+			if ( backgroundPlaneCamera === undefined ) {
+
+				backgroundPlaneCamera = new OrthographicCamera( - 1, 1, 1, - 1, 0, 1 );
+
+				backgroundPlaneMesh = new Mesh(
+					new PlaneBufferGeometry( 2, 2 ),
+					new MeshBasicMaterial( { depthTest: false, depthWrite: false, fog: false } )
+				);
+
+			}
+
 			backgroundPlaneMesh.material.map = background;
 
 			objects.update( backgroundPlaneMesh );
 
-			_this.renderBufferDirect( backgroundCamera, null, backgroundPlaneMesh.geometry, backgroundPlaneMesh.material, backgroundPlaneMesh, null );
+			_this.renderBufferDirect( backgroundPlaneCamera, null, backgroundPlaneMesh.geometry, backgroundPlaneMesh.material, backgroundPlaneMesh, null );
 
 		}