PMREMGenerator: Refactor code.

src/extras/PMREMGenerator.js

@@ -62,14 +62,7 @@ var ENCODINGS = {
 };
 
 var _flatCamera = new OrthographicCamera();
-var _blurMaterial = _getBlurShader( MAX_SAMPLES );
-var _equirectShader = null;
-var _cubemapShader = null;
-
 var { _lodPlanes, _sizeLods, _sigmas } = _createPlanes();
-var _pingPongRenderTarget = null;
-var _renderer = null;
-
 var _oldTarget = null;
 
 // Golden Ratio
@@ -91,8 +84,14 @@ var _axisDirections = [
 
 function PMREMGenerator( renderer ) {
 
-	_renderer = renderer;
-	_compileMaterial( _blurMaterial );
+	this._renderer = renderer;
+	this._pingPongRenderTarget = null;
+
+	this._blurMaterial = _getBlurShader( MAX_SAMPLES );
+	this._equirectShader = null;
+	this._cubemapShader = null;
+
+	this._compileMaterial( this._blurMaterial );
 
 }
 
@@ -109,16 +108,17 @@ PMREMGenerator.prototype = {
 	 */
 	fromScene: function ( scene, sigma = 0, near = 0.1, far = 100 ) {
 
-		_oldTarget = _renderer.getRenderTarget();
-		var cubeUVRenderTarget = _allocateTargets();
-		_sceneToCubeUV( scene, near, far, cubeUVRenderTarget );
+		_oldTarget = this._renderer.getRenderTarget();
+		var cubeUVRenderTarget = this._allocateTargets();
+
+		this._sceneToCubeUV( scene, near, far, cubeUVRenderTarget );
 		if ( sigma > 0 ) {
 
-			_blur( cubeUVRenderTarget, 0, 0, sigma );
+			this._blur( cubeUVRenderTarget, 0, 0, sigma );
 
 		}
-		_applyPMREM( cubeUVRenderTarget );
-		_cleanup( cubeUVRenderTarget );
+		this._applyPMREM( cubeUVRenderTarget );
+		this._cleanup( cubeUVRenderTarget );
 
 		return cubeUVRenderTarget;
 
@@ -146,11 +146,11 @@ PMREMGenerator.prototype = {
 	 */
 	fromCubemap: function ( cubemap ) {
 
-		_oldTarget = _renderer.getRenderTarget();
-		var cubeUVRenderTarget = _allocateTargets( cubemap );
-		_textureToCubeUV( cubemap, cubeUVRenderTarget );
-		_applyPMREM( cubeUVRenderTarget );
-		_cleanup( cubeUVRenderTarget );
+		_oldTarget = this._renderer.getRenderTarget();
+		var cubeUVRenderTarget = this._allocateTargets( cubemap );
+		this._textureToCubeUV( cubemap, cubeUVRenderTarget );
+		this._applyPMREM( cubeUVRenderTarget );
+		this._cleanup( cubeUVRenderTarget );
 
 		return cubeUVRenderTarget;
 
@@ -162,10 +162,10 @@ PMREMGenerator.prototype = {
 	 */
 	compileCubemapShader: function () {
 
-		if ( _cubemapShader == null ) {
+		if ( this._cubemapShader === null ) {
 
-			_cubemapShader = _getCubemapShader();
-			_compileMaterial( _cubemapShader );
+			this._cubemapShader = _getCubemapShader();
+			this._compileMaterial( this._cubemapShader );
 
 		}
 
@@ -177,10 +177,10 @@ PMREMGenerator.prototype = {
 	 */
 	compileEquirectangularShader: function () {
 
-		if ( _equirectShader == null ) {
+		if ( this._equirectShader === null ) {
 
-			_equirectShader = _getEquirectShader();
-			_compileMaterial( _equirectShader );
+			this._equirectShader = _getEquirectShader();
+			this._compileMaterial( this._equirectShader );
 
 		}
 
@@ -193,10 +193,10 @@ PMREMGenerator.prototype = {
 	 */
 	dispose: function () {
 
-		_blurMaterial.dispose();
+		this._blurMaterial.dispose();
 
-		if ( _cubemapShader != null ) _cubemapShader.dispose();
-		if ( _equirectShader != null ) _equirectShader.dispose();
+		if ( this._cubemapShader !== null ) this._cubemapShader.dispose();
+		if ( this._equirectShader !== null ) this._equirectShader.dispose();
 
 		for ( var i = 0; i < _lodPlanes.length; i ++ ) {
 
@@ -206,369 +206,382 @@ PMREMGenerator.prototype = {
 
 	},
 
-};
+	// private interface
 
-function _createPlanes() {
+	_cleanup: function ( outputTarget ) {
 
-	var _lodPlanes = [];
-	var _sizeLods = [];
-	var _sigmas = [];
+		this._pingPongRenderTarget.dispose();
+		this._renderer.setRenderTarget( _oldTarget );
+		outputTarget.scissorTest = false;
+		// reset viewport and scissor
+		outputTarget.setSize( outputTarget.width, outputTarget.height );
 
-	var lod = LOD_MAX;
-	for ( var i = 0; i < TOTAL_LODS; i ++ ) {
+	},
 
-		var sizeLod = Math.pow( 2, lod );
-		_sizeLods.push( sizeLod );
-		var sigma = 1.0 / sizeLod;
-		if ( i > LOD_MAX - LOD_MIN ) {
+	_allocateTargets: function ( equirectangular ) {
+
+		var params = {
+			magFilter: NearestFilter,
+			minFilter: NearestFilter,
+			generateMipmaps: false,
+			type: equirectangular ? equirectangular.type : UnsignedByteType,
+			format: equirectangular ? equirectangular.format : RGBEFormat,
+			encoding: equirectangular ? equirectangular.encoding : RGBEEncoding,
+			depthBuffer: false,
+			stencilBuffer: false
+		};
+		var cubeUVRenderTarget = _createRenderTarget( params );
+		cubeUVRenderTarget.depthBuffer = equirectangular ? false : true;
+		this._pingPongRenderTarget = _createRenderTarget( params );
+		return cubeUVRenderTarget;
 
-			sigma = EXTRA_LOD_SIGMA[ i - LOD_MAX + LOD_MIN - 1 ];
+	},
 
-		} else if ( i == 0 ) {
+	_compileMaterial: function ( material ) {
 
-			sigma = 0;
+		var tmpScene = new Scene();
+		tmpScene.add( new Mesh( _lodPlanes[ 0 ], material ) );
+		this._renderer.compile( tmpScene, _flatCamera );
+
+	},
+
+	_sceneToCubeUV: function ( scene, near, far, cubeUVRenderTarget ) {
+
+		var fov = 90;
+		var aspect = 1;
+		var cubeCamera = new PerspectiveCamera( fov, aspect, near, far );
+		var upSign = [ 1, 1, 1, 1, - 1, 1 ];
+		var forwardSign = [ 1, 1, - 1, - 1, - 1, 1 ];
+		var renderer = this._renderer;
+
+		var outputEncoding = renderer.outputEncoding;
+		var toneMapping = renderer.toneMapping;
+		var toneMappingExposure = renderer.toneMappingExposure;
+		var clearColor = renderer.getClearColor();
+		var clearAlpha = renderer.getClearAlpha();
+
+		renderer.toneMapping = LinearToneMapping;
+		renderer.toneMappingExposure = 1.0;
+		renderer.outputEncoding = LinearEncoding;
+		scene.scale.z *= - 1;
+
+		var background = scene.background;
+		if ( background && background.isColor ) {
+
+			background.convertSRGBToLinear();
+			// Convert linear to RGBE
+			var maxComponent = Math.max( background.r, background.g, background.b );
+			var fExp = Math.min( Math.max( Math.ceil( Math.log2( maxComponent ) ), - 128.0 ), 127.0 );
+			background = background.multiplyScalar( Math.pow( 2.0, - fExp ) );
+			var alpha = ( fExp + 128.0 ) / 255.0;
+			renderer.setClearColor( background, alpha );
+			scene.background = null;
 
 		}
-		_sigmas.push( sigma );
 
-		var texelSize = 1.0 / ( sizeLod - 1 );
-		var min = - texelSize / 2;
-		var max = 1 + texelSize / 2;
-		var uv1 = [ min, min, max, min, max, max, min, min, max, max, min, max ];
+		for ( var i = 0; i < 6; i ++ ) {
 
-		var cubeFaces = 6;
-		var vertices = 6;
-		var positionSize = 3;
-		var uvSize = 2;
-		var faceIndexSize = 1;
+			var col = i % 3;
+			if ( col == 0 ) {
 
-		var position = new Float32Array( positionSize * vertices * cubeFaces );
-		var uv = new Float32Array( uvSize * vertices * cubeFaces );
-		var faceIndex = new Float32Array( faceIndexSize * vertices * cubeFaces );
+				cubeCamera.up.set( 0, upSign[ i ], 0 );
+				cubeCamera.lookAt( forwardSign[ i ], 0, 0 );
 
-		for ( var face = 0; face < cubeFaces; face ++ ) {
+			} else if ( col == 1 ) {
 
-			var x = ( face % 3 ) * 2 / 3 - 1;
-			var y = face > 2 ? 0 : - 1;
-			var coordinates = [
-				x, y, 0,
-				x + 2 / 3, y, 0,
-				x + 2 / 3, y + 1, 0,
-				x, y, 0,
-				x + 2 / 3, y + 1, 0,
-				x, y + 1, 0
-			];
-			position.set( coordinates, positionSize * vertices * face );
-			uv.set( uv1, uvSize * vertices * face );
-			var fill = [ face, face, face, face, face, face ];
-			faceIndex.set( fill, faceIndexSize * vertices * face );
+				cubeCamera.up.set( 0, 0, upSign[ i ] );
+				cubeCamera.lookAt( 0, forwardSign[ i ], 0 );
 
-		}
-		var planes = new BufferGeometry();
-		planes.setAttribute( 'position', new BufferAttribute( position, positionSize ) );
-		planes.setAttribute( 'uv', new BufferAttribute( uv, uvSize ) );
-		planes.setAttribute( 'faceIndex', new BufferAttribute( faceIndex, faceIndexSize ) );
-		_lodPlanes.push( planes );
+			} else {
 
-		if ( lod > LOD_MIN ) {
+				cubeCamera.up.set( 0, upSign[ i ], 0 );
+				cubeCamera.lookAt( 0, 0, forwardSign[ i ] );
 
-			lod --;
+			}
+			_setViewport( cubeUVRenderTarget,
+				col * SIZE_MAX, i > 2 ? SIZE_MAX : 0, SIZE_MAX, SIZE_MAX );
+			renderer.setRenderTarget( cubeUVRenderTarget );
+			renderer.render( scene, cubeCamera );
 
 		}
 
-	}
-	return { _lodPlanes, _sizeLods, _sigmas };
+		renderer.toneMapping = toneMapping;
+		renderer.toneMappingExposure = toneMappingExposure;
+		renderer.outputEncoding = outputEncoding;
+		renderer.setClearColor( clearColor, clearAlpha );
+		scene.scale.z *= - 1;
 
-}
+	},
 
-function _allocateTargets( equirectangular ) {
-
-	var params = {
-		magFilter: NearestFilter,
-		minFilter: NearestFilter,
-		generateMipmaps: false,
-		type: equirectangular ? equirectangular.type : UnsignedByteType,
-		format: equirectangular ? equirectangular.format : RGBEFormat,
-		encoding: equirectangular ? equirectangular.encoding : RGBEEncoding,
-		depthBuffer: false,
-		stencilBuffer: false
-	};
-	var cubeUVRenderTarget = _createRenderTarget( params );
-	cubeUVRenderTarget.depthBuffer = equirectangular ? false : true;
-	_pingPongRenderTarget = _createRenderTarget( params );
-	return cubeUVRenderTarget;
+	_textureToCubeUV: function ( texture, cubeUVRenderTarget ) {
 
-}
+		var scene = new Scene();
+		var renderer = this._renderer;
 
-function _cleanup( outputTarget ) {
+		if ( texture.isCubeTexture ) {
 
-	_pingPongRenderTarget.dispose();
-	_renderer.setRenderTarget( _oldTarget );
-	outputTarget.scissorTest = false;
-	// reset viewport and scissor
-	outputTarget.setSize( outputTarget.width, outputTarget.height );
+			if ( this._cubemapShader == null ) {
 
-}
+				this._cubemapShader = _getCubemapShader();
 
-function _sceneToCubeUV( scene, near, far, cubeUVRenderTarget ) {
-
-	var fov = 90;
-	var aspect = 1;
-	var cubeCamera = new PerspectiveCamera( fov, aspect, near, far );
-	var upSign = [ 1, 1, 1, 1, - 1, 1 ];
-	var forwardSign = [ 1, 1, - 1, - 1, - 1, 1 ];
-
-	var outputEncoding = _renderer.outputEncoding;
-	var toneMapping = _renderer.toneMapping;
-	var toneMappingExposure = _renderer.toneMappingExposure;
-	var clearColor = _renderer.getClearColor();
-	var clearAlpha = _renderer.getClearAlpha();
-
-	_renderer.toneMapping = LinearToneMapping;
-	_renderer.toneMappingExposure = 1.0;
-	_renderer.outputEncoding = LinearEncoding;
-	scene.scale.z *= - 1;
-
-	var background = scene.background;
-	if ( background && background.isColor ) {
-
-		background.convertSRGBToLinear();
-		// Convert linear to RGBE
-		var maxComponent = Math.max( background.r, background.g, background.b );
-		var fExp = Math.min( Math.max( Math.ceil( Math.log2( maxComponent ) ), - 128.0 ), 127.0 );
-		background = background.multiplyScalar( Math.pow( 2.0, - fExp ) );
-		var alpha = ( fExp + 128.0 ) / 255.0;
-		_renderer.setClearColor( background, alpha );
-		scene.background = null;
+			}
 
-	}
+		} else {
 
-	for ( var i = 0; i < 6; i ++ ) {
+			if ( this._equirectShader == null ) {
 
-		var col = i % 3;
-		if ( col == 0 ) {
+				this._equirectShader = _getEquirectShader();
 
-			cubeCamera.up.set( 0, upSign[ i ], 0 );
-			cubeCamera.lookAt( forwardSign[ i ], 0, 0 );
+			}
 
-		} else if ( col == 1 ) {
+		}
 
-			cubeCamera.up.set( 0, 0, upSign[ i ] );
-			cubeCamera.lookAt( 0, forwardSign[ i ], 0 );
+		var material = texture.isCubeTexture ? this._cubemapShader : this._equirectShader;
+		scene.add( new Mesh( _lodPlanes[ 0 ], material ) );
+		var uniforms = material.uniforms;
 
-		} else {
+		uniforms[ 'envMap' ].value = texture;
+		if ( ! texture.isCubeTexture ) {
 
-			cubeCamera.up.set( 0, upSign[ i ], 0 );
-			cubeCamera.lookAt( 0, 0, forwardSign[ i ] );
+			uniforms[ 'texelSize' ].value.set( 1.0 / texture.image.width, 1.0 / texture.image.height );
 
 		}
-		_setViewport( cubeUVRenderTarget,
-			col * SIZE_MAX, i > 2 ? SIZE_MAX : 0, SIZE_MAX, SIZE_MAX );
-		_renderer.setRenderTarget( cubeUVRenderTarget );
-		_renderer.render( scene, cubeCamera );
+		uniforms[ 'inputEncoding' ].value = ENCODINGS[ texture.encoding ];
+		uniforms[ 'outputEncoding' ].value = ENCODINGS[ texture.encoding ];
 
-	}
+		_setViewport( cubeUVRenderTarget, 0, 0, 3 * SIZE_MAX, 2 * SIZE_MAX );
+		renderer.setRenderTarget( cubeUVRenderTarget );
+		renderer.render( scene, _flatCamera );
 
-	_renderer.toneMapping = toneMapping;
-	_renderer.toneMappingExposure = toneMappingExposure;
-	_renderer.outputEncoding = outputEncoding;
-	_renderer.setClearColor( clearColor, clearAlpha );
-	scene.scale.z *= - 1;
-
-}
+	},
 
-function _textureToCubeUV( texture, cubeUVRenderTarget ) {
+	_applyPMREM: function ( cubeUVRenderTarget ) {
 
-	var scene = new Scene();
-	if ( texture.isCubeTexture ) {
+		var renderer = this._renderer;
+		var autoClear = renderer.autoClear;
+		renderer.autoClear = false;
 
-		if ( _cubemapShader == null ) {
+		for ( var i = 1; i < TOTAL_LODS; i ++ ) {
 
-			_cubemapShader = _getCubemapShader();
+			var sigma = Math.sqrt(
+				_sigmas[ i ] * _sigmas[ i ] -
+			_sigmas[ i - 1 ] * _sigmas[ i - 1 ] );
+			var poleAxis =
+			_axisDirections[ ( i - 1 ) % _axisDirections.length ];
+			this._blur( cubeUVRenderTarget, i - 1, i, sigma, poleAxis );
 
 		}
 
-	} else {
+		renderer.autoClear = autoClear;
 
-		if ( _equirectShader == null ) {
+	},
 
-			_equirectShader = _getEquirectShader();
+	/**
+	 * This is a two-pass Gaussian blur for a cubemap. Normally this is done
+	 * vertically and horizontally, but this breaks down on a cube. Here we apply
+	 * the blur latitudinally (around the poles), and then longitudinally (towards
+	 * the poles) to approximate the orthogonally-separable blur. It is least
+	 * accurate at the poles, but still does a decent job.
+	 */
+	_blur: function ( cubeUVRenderTarget, lodIn, lodOut, sigma, poleAxis ) {
+
+		var pingPongRenderTarget = this._pingPongRenderTarget;
+
+		this._halfBlur(
+			cubeUVRenderTarget,
+			pingPongRenderTarget,
+			lodIn,
+			lodOut,
+			sigma,
+			'latitudinal',
+			poleAxis );
+
+		this._halfBlur(
+			pingPongRenderTarget,
+			cubeUVRenderTarget,
+			lodOut,
+			lodOut,
+			sigma,
+			'longitudinal',
+			poleAxis );
 
-		}
+	},
 
-	}
-	var material = texture.isCubeTexture ? _cubemapShader : _equirectShader;
-	scene.add( new Mesh( _lodPlanes[ 0 ], material ) );
-	var uniforms = material.uniforms;
+	_halfBlur: function ( targetIn, targetOut, lodIn, lodOut, sigmaRadians, direction, poleAxis ) {
 
-	uniforms[ 'envMap' ].value = texture;
-	if ( ! texture.isCubeTexture ) {
+		var renderer = this._renderer;
+		var blurMaterial = this._blurMaterial;
 
-		uniforms[ 'texelSize' ].value.set( 1.0 / texture.image.width, 1.0 / texture.image.height );
+		if ( direction !== 'latitudinal' && direction !== 'longitudinal' ) {
 
-	}
-	uniforms[ 'inputEncoding' ].value = ENCODINGS[ texture.encoding ];
-	uniforms[ 'outputEncoding' ].value = ENCODINGS[ texture.encoding ];
+			console.error(
+				'blur direction must be either latitudinal or longitudinal!' );
 
-	_setViewport( cubeUVRenderTarget, 0, 0, 3 * SIZE_MAX, 2 * SIZE_MAX );
-	_renderer.setRenderTarget( cubeUVRenderTarget );
-	_renderer.render( scene, _flatCamera );
+		}
 
-}
+		// Number of standard deviations at which to cut off the discrete approximation.
+		var STANDARD_DEVIATIONS = 3;
 
-function _compileMaterial( material ) {
+		var blurScene = new Scene();
+		blurScene.add( new Mesh( _lodPlanes[ lodOut ], blurMaterial ) );
+		var blurUniforms = blurMaterial.uniforms;
 
-	var tmpScene = new Scene();
-	tmpScene.add( new Mesh( _lodPlanes[ 0 ], material ) );
-	_renderer.compile( tmpScene, _flatCamera );
+		var pixels = _sizeLods[ lodIn ] - 1;
+		var radiansPerPixel = isFinite( sigmaRadians ) ? Math.PI / ( 2 * pixels ) : 2 * Math.PI / ( 2 * MAX_SAMPLES - 1 );
+		var sigmaPixels = sigmaRadians / radiansPerPixel;
+		var samples = isFinite( sigmaRadians ) ? 1 + Math.floor( STANDARD_DEVIATIONS * sigmaPixels ) : MAX_SAMPLES;
 
-}
+		if ( samples > MAX_SAMPLES ) {
 
-function _createRenderTarget( params ) {
+			console.warn( `sigmaRadians, ${
+				sigmaRadians}, is too large and will clip, as it requested ${
+				samples} samples when the maximum is set to ${MAX_SAMPLES}` );
 
-	var cubeUVRenderTarget = new WebGLRenderTarget( 3 * SIZE_MAX, 3 * SIZE_MAX, params );
-	cubeUVRenderTarget.texture.mapping = CubeUVReflectionMapping;
-	cubeUVRenderTarget.texture.name = 'PMREM.cubeUv';
-	cubeUVRenderTarget.scissorTest = true;
-	return cubeUVRenderTarget;
+		}
 
-}
+		var weights = [];
+		var sum = 0;
 
-function _setViewport( target, x, y, width, height ) {
+		for ( var i = 0; i < MAX_SAMPLES; ++ i ) {
 
-	target.viewport.set( x, y, width, height );
-	target.scissor.set( x, y, width, height );
+			var x = i / sigmaPixels;
+			var weight = Math.exp( - x * x / 2 );
+			weights.push( weight );
 
-}
+			if ( i == 0 ) {
 
-function _applyPMREM( cubeUVRenderTarget ) {
+				sum += weight;
 
-	var autoClear = _renderer.autoClear;
-	_renderer.autoClear = false;
+			} else if ( i < samples ) {
 
-	for ( var i = 1; i < TOTAL_LODS; i ++ ) {
+				sum += 2 * weight;
 
-		var sigma = Math.sqrt(
-			_sigmas[ i ] * _sigmas[ i ] -
-		_sigmas[ i - 1 ] * _sigmas[ i - 1 ] );
-		var poleAxis =
-		_axisDirections[ ( i - 1 ) % _axisDirections.length ];
-		_blur( cubeUVRenderTarget, i - 1, i, sigma, poleAxis );
+			}
 
-	}
+		}
 
-	_renderer.autoClear = autoClear;
+		for ( var i = 0; i < weights.length; i ++ ) {
 
-}
+			weights[ i ] = weights[ i ] / sum;
 
-/**
- * This is a two-pass Gaussian blur for a cubemap. Normally this is done
- * vertically and horizontally, but this breaks down on a cube. Here we apply
- * the blur latitudinally (around the poles), and then longitudinally (towards
- * the poles) to approximate the orthogonally-separable blur. It is least
- * accurate at the poles, but still does a decent job.
- */
-function _blur( cubeUVRenderTarget, lodIn, lodOut, sigma, poleAxis ) {
-
-	_halfBlur(
-		cubeUVRenderTarget,
-		_pingPongRenderTarget,
-		lodIn,
-		lodOut,
-		sigma,
-		'latitudinal',
-		poleAxis );
-
-	_halfBlur(
-		_pingPongRenderTarget,
-		cubeUVRenderTarget,
-		lodOut,
-		lodOut,
-		sigma,
-		'longitudinal',
-		poleAxis );
+		}
 
-}
+		blurUniforms[ 'envMap' ].value = targetIn.texture;
+		blurUniforms[ 'samples' ].value = samples;
+		blurUniforms[ 'weights' ].value = weights;
+		blurUniforms[ 'latitudinal' ].value = direction === 'latitudinal';
+		if ( poleAxis ) {
+
+			blurUniforms[ 'poleAxis' ].value = poleAxis;
 
-function _halfBlur( targetIn, targetOut, lodIn, lodOut, sigmaRadians, direction, poleAxis ) {
+		}
+		blurUniforms[ 'dTheta' ].value = radiansPerPixel;
+		blurUniforms[ 'mipInt' ].value = LOD_MAX - lodIn;
+		blurUniforms[ 'inputEncoding' ].value = ENCODINGS[ targetIn.texture.encoding ];
+		blurUniforms[ 'outputEncoding' ].value = ENCODINGS[ targetIn.texture.encoding ];
 
-	if ( direction !== 'latitudinal' && direction !== 'longitudinal' ) {
+		var outputSize = _sizeLods[ lodOut ];
+		var x = 3 * Math.max( 0, SIZE_MAX - 2 * outputSize );
+		var y = ( lodOut === 0 ? 0 : 2 * SIZE_MAX ) +
+		2 * outputSize *
+			( lodOut > LOD_MAX - LOD_MIN ? lodOut - LOD_MAX + LOD_MIN : 0 );
 
-		console.error(
-			'blur direction must be either latitudinal or longitudinal!' );
+		_setViewport( targetOut, x, y, 3 * outputSize, 2 * outputSize );
+		renderer.setRenderTarget( targetOut );
+		renderer.render( blurScene, _flatCamera );
 
 	}
 
-	// Number of standard deviations at which to cut off the discrete approximation.
-	var STANDARD_DEVIATIONS = 3;
+};
 
-	var blurScene = new Scene();
-	blurScene.add( new Mesh( _lodPlanes[ lodOut ], _blurMaterial ) );
-	var blurUniforms = _blurMaterial.uniforms;
+function _createPlanes() {
 
-	var pixels = _sizeLods[ lodIn ] - 1;
-	var radiansPerPixel = isFinite( sigmaRadians ) ? Math.PI / ( 2 * pixels ) : 2 * Math.PI / ( 2 * MAX_SAMPLES - 1 );
-	var sigmaPixels = sigmaRadians / radiansPerPixel;
-	var samples = isFinite( sigmaRadians ) ? 1 + Math.floor( STANDARD_DEVIATIONS * sigmaPixels ) : MAX_SAMPLES;
+	var _lodPlanes = [];
+	var _sizeLods = [];
+	var _sigmas = [];
 
-	if ( samples > MAX_SAMPLES ) {
+	var lod = LOD_MAX;
+	for ( var i = 0; i < TOTAL_LODS; i ++ ) {
 
-		console.warn( `sigmaRadians, ${
-			sigmaRadians}, is too large and will clip, as it requested ${
-			samples} samples when the maximum is set to ${MAX_SAMPLES}` );
+		var sizeLod = Math.pow( 2, lod );
+		_sizeLods.push( sizeLod );
+		var sigma = 1.0 / sizeLod;
+		if ( i > LOD_MAX - LOD_MIN ) {
 
-	}
+			sigma = EXTRA_LOD_SIGMA[ i - LOD_MAX + LOD_MIN - 1 ];
 
-	var weights = [];
-	var sum = 0;
+		} else if ( i == 0 ) {
 
-	for ( var i = 0; i < MAX_SAMPLES; ++ i ) {
+			sigma = 0;
 
-		var x = i / sigmaPixels;
-		var weight = Math.exp( - x * x / 2 );
-		weights.push( weight );
+		}
+		_sigmas.push( sigma );
 
-		if ( i == 0 ) {
+		var texelSize = 1.0 / ( sizeLod - 1 );
+		var min = - texelSize / 2;
+		var max = 1 + texelSize / 2;
+		var uv1 = [ min, min, max, min, max, max, min, min, max, max, min, max ];
 
-			sum += weight;
+		var cubeFaces = 6;
+		var vertices = 6;
+		var positionSize = 3;
+		var uvSize = 2;
+		var faceIndexSize = 1;
 
-		} else if ( i < samples ) {
+		var position = new Float32Array( positionSize * vertices * cubeFaces );
+		var uv = new Float32Array( uvSize * vertices * cubeFaces );
+		var faceIndex = new Float32Array( faceIndexSize * vertices * cubeFaces );
+
+		for ( var face = 0; face < cubeFaces; face ++ ) {
+
+			var x = ( face % 3 ) * 2 / 3 - 1;
+			var y = face > 2 ? 0 : - 1;
+			var coordinates = [
+				x, y, 0,
+				x + 2 / 3, y, 0,
+				x + 2 / 3, y + 1, 0,
+				x, y, 0,
+				x + 2 / 3, y + 1, 0,
+				x, y + 1, 0
+			];
+			position.set( coordinates, positionSize * vertices * face );
+			uv.set( uv1, uvSize * vertices * face );
+			var fill = [ face, face, face, face, face, face ];
+			faceIndex.set( fill, faceIndexSize * vertices * face );
+
+		}
+		var planes = new BufferGeometry();
+		planes.setAttribute( 'position', new BufferAttribute( position, positionSize ) );
+		planes.setAttribute( 'uv', new BufferAttribute( uv, uvSize ) );
+		planes.setAttribute( 'faceIndex', new BufferAttribute( faceIndex, faceIndexSize ) );
+		_lodPlanes.push( planes );
 
-			sum += 2 * weight;
+		if ( lod > LOD_MIN ) {
+
+			lod --;
 
 		}
 
 	}
 
-	for ( var i = 0; i < weights.length; i ++ ) {
+	return { _lodPlanes, _sizeLods, _sigmas };
 
-		weights[ i ] = weights[ i ] / sum;
+}
 
-	}
+function _createRenderTarget( params ) {
 
-	blurUniforms[ 'envMap' ].value = targetIn.texture;
-	blurUniforms[ 'samples' ].value = samples;
-	blurUniforms[ 'weights' ].value = weights;
-	blurUniforms[ 'latitudinal' ].value = direction === 'latitudinal';
-	if ( poleAxis ) {
+	var cubeUVRenderTarget = new WebGLRenderTarget( 3 * SIZE_MAX, 3 * SIZE_MAX, params );
+	cubeUVRenderTarget.texture.mapping = CubeUVReflectionMapping;
+	cubeUVRenderTarget.texture.name = 'PMREM.cubeUv';
+	cubeUVRenderTarget.scissorTest = true;
+	return cubeUVRenderTarget;
 
-		blurUniforms[ 'poleAxis' ].value = poleAxis;
+}
 
-	}
-	blurUniforms[ 'dTheta' ].value = radiansPerPixel;
-	blurUniforms[ 'mipInt' ].value = LOD_MAX - lodIn;
-	blurUniforms[ 'inputEncoding' ].value = ENCODINGS[ targetIn.texture.encoding ];
-	blurUniforms[ 'outputEncoding' ].value = ENCODINGS[ targetIn.texture.encoding ];
-
-	var outputSize = _sizeLods[ lodOut ];
-	var x = 3 * Math.max( 0, SIZE_MAX - 2 * outputSize );
-	var y = ( lodOut === 0 ? 0 : 2 * SIZE_MAX ) +
-	2 * outputSize *
-		( lodOut > LOD_MAX - LOD_MIN ? lodOut - LOD_MAX + LOD_MIN : 0 );
-
-	_setViewport( targetOut, x, y, 3 * outputSize, 2 * outputSize );
-	_renderer.setRenderTarget( targetOut );
-	_renderer.render( blurScene, _flatCamera );
+function _setViewport( target, x, y, width, height ) {
+
+	target.viewport.set( x, y, width, height );
+	target.scissor.set( x, y, width, height );
 
 }