constructor( { renderer, scene, camera, width = 512, height = 512, selects = null, bouncing = false, groundReflector = null } ) {

		super();

		/**
		 * The width of the effect.
		 *
		 * @type {number}
		 * @default 512
		 */
		this.width = width;

		/**
		 * The height of the effect.
		 *
		 * @type {number}
		 * @default 512
		 */
		this.height = height;

		/**
		 * Overwritten to perform a clear operation by default.
		 *
		 * @type {boolean}
		 * @default true
		 */
		this.clear = true;

		/**
		 * The renderer.
		 *
		 * @type {WebGLRenderer}
		 */
		this.renderer = renderer;

		/**
		 * The scene to render.
		 *
		 * @type {Scene}
		 */
		this.scene = scene;

		/**
		 * The camera.
		 *
		 * @type {Camera}
		 */
		this.camera = camera;

		/**
		 * The ground reflector.
		 *
		 * @type {?ReflectorForSSRPass}
		 * @default 0
		 */
		this.groundReflector = groundReflector;

		/**
		 * The opacity.
		 *
		 * @type {number}
		 * @default 0.5
		 */
		this.opacity = SSRShader.uniforms.opacity.value;

		/**
		 * The output configuration.
		 *
		 * @type {number}
		 * @default 0
		 */
		this.output = 0;

		/**
		 * Controls how far a fragment can reflect.
		 *
		 * @type {number}
		 * @default 180
		 */
		this.maxDistance = SSRShader.uniforms.maxDistance.value;

		/**
		 * Controls the cutoff between what counts as a
		 * possible reflection hit and what does not.
		 *
		 * @type {number}
		 * @default .018
		 */
		this.thickness = SSRShader.uniforms.thickness.value;

		this.tempColor = new Color();

		this._selects = selects;

		/**
		 * Whether the pass is selective or not.
		 *
		 * @type {boolean}
		 * @default false
		 */
		this.selective = Array.isArray( this._selects );

		/**
		 * Which 3D objects should be affected by SSR. If not set, the entire scene is affected.
		 *
		 * @name SSRPass#selects
		 * @type {?Array<Object3D>}
		 * @default null
		 */
		Object.defineProperty( this, 'selects', {
			get() {

				return this._selects;

			},
			set( val ) {

				if ( this._selects === val ) return;
				this._selects = val;
				if ( Array.isArray( val ) ) {

					this.selective = true;
					this.ssrMaterial.defines.SELECTIVE = true;
					this.ssrMaterial.needsUpdate = true;

				} else {

					this.selective = false;
					this.ssrMaterial.defines.SELECTIVE = false;
					this.ssrMaterial.needsUpdate = true;

				}

			}
		} );

		this._bouncing = bouncing;

		/**
		 * Whether bouncing is enabled or not.
		 *
		 * @name SSRPass#bouncing
		 * @type {boolean}
		 * @default false
		 */
		Object.defineProperty( this, 'bouncing', {
			get() {

				return this._bouncing;

			},
			set( val ) {

				if ( this._bouncing === val ) return;
				this._bouncing = val;
				if ( val ) {

					this.ssrMaterial.uniforms[ 'tDiffuse' ].value = this.prevRenderTarget.texture;

				} else {

					this.ssrMaterial.uniforms[ 'tDiffuse' ].value = this.beautyRenderTarget.texture;

				}

			}
		} );

		/**
		 * Whether to blur reflections or not.
		 *
		 * @type {boolean}
		 * @default true
		 */
		this.blur = true;

		this._distanceAttenuation = SSRShader.defines.DISTANCE_ATTENUATION;

		/**
		 * Whether to use distance attenuation or not.
		 *
		 * @name SSRPass#distanceAttenuation
		 * @type {boolean}
		 * @default true
		 */
		Object.defineProperty( this, 'distanceAttenuation', {
			get() {

				return this._distanceAttenuation;

			},
			set( val ) {

				if ( this._distanceAttenuation === val ) return;
				this._distanceAttenuation = val;
				this.ssrMaterial.defines.DISTANCE_ATTENUATION = val;
				this.ssrMaterial.needsUpdate = true;

			}
		} );


		this._fresnel = SSRShader.defines.FRESNEL;

		/**
		 * Whether to use fresnel or not.
		 *
		 * @name SSRPass#fresnel
		 * @type {boolean}
		 * @default true
		 */
		Object.defineProperty( this, 'fresnel', {
			get() {

				return this._fresnel;

			},
			set( val ) {

				if ( this._fresnel === val ) return;
				this._fresnel = val;
				this.ssrMaterial.defines.FRESNEL = val;
				this.ssrMaterial.needsUpdate = true;

			}
		} );

		this._infiniteThick = SSRShader.defines.INFINITE_THICK;

		/**
		 * Whether to use infinite thickness or not.
		 *
		 * @name SSRPass#infiniteThick
		 * @type {boolean}
		 * @default false
		 */
		Object.defineProperty( this, 'infiniteThick', {
			get() {

				return this._infiniteThick;

			},
			set( val ) {

				if ( this._infiniteThick === val ) return;
				this._infiniteThick = val;
				this.ssrMaterial.defines.INFINITE_THICK = val;
				this.ssrMaterial.needsUpdate = true;

			}
		} );

		// beauty render target with depth buffer

		const depthTexture = new DepthTexture();
		depthTexture.type = UnsignedShortType;
		depthTexture.minFilter = NearestFilter;
		depthTexture.magFilter = NearestFilter;

		this.beautyRenderTarget = new WebGLRenderTarget( this.width, this.height, {
			minFilter: NearestFilter,
			magFilter: NearestFilter,
			type: HalfFloatType,
			depthTexture: depthTexture,
			depthBuffer: true
		} );

		//for bouncing
		this.prevRenderTarget = new WebGLRenderTarget( this.width, this.height, {
			minFilter: NearestFilter,
			magFilter: NearestFilter
		} );

		// normal render target

		this.normalRenderTarget = new WebGLRenderTarget( this.width, this.height, {
			minFilter: NearestFilter,
			magFilter: NearestFilter,
			type: HalfFloatType,
		} );

		// metalness render target

		this.metalnessRenderTarget = new WebGLRenderTarget( this.width, this.height, {
			minFilter: NearestFilter,
			magFilter: NearestFilter,
			type: HalfFloatType,
		} );



		// ssr render target

		this.ssrRenderTarget = new WebGLRenderTarget( this.width, this.height, {
			minFilter: NearestFilter,
			magFilter: NearestFilter
		} );

		this.blurRenderTarget = this.ssrRenderTarget.clone();
		this.blurRenderTarget2 = this.ssrRenderTarget.clone();
		// this.blurRenderTarget3 = this.ssrRenderTarget.clone();

		// ssr material

		this.ssrMaterial = new ShaderMaterial( {
			defines: Object.assign( {}, SSRShader.defines, {
				MAX_STEP: Math.sqrt( this.width * this.width + this.height * this.height )
			} ),
			uniforms: UniformsUtils.clone( SSRShader.uniforms ),
			vertexShader: SSRShader.vertexShader,
			fragmentShader: SSRShader.fragmentShader,
			blending: NoBlending
		} );

		this.ssrMaterial.uniforms[ 'tDiffuse' ].value = this.beautyRenderTarget.texture;
		this.ssrMaterial.uniforms[ 'tNormal' ].value = this.normalRenderTarget.texture;
		this.ssrMaterial.defines.SELECTIVE = this.selective;
		this.ssrMaterial.needsUpdate = true;
		this.ssrMaterial.uniforms[ 'tMetalness' ].value = this.metalnessRenderTarget.texture;
		this.ssrMaterial.uniforms[ 'tDepth' ].value = this.beautyRenderTarget.depthTexture;
		this.ssrMaterial.uniforms[ 'cameraNear' ].value = this.camera.near;
		this.ssrMaterial.uniforms[ 'cameraFar' ].value = this.camera.far;
		this.ssrMaterial.uniforms[ 'thickness' ].value = this.thickness;
		this.ssrMaterial.uniforms[ 'resolution' ].value.set( this.width, this.height );
		this.ssrMaterial.uniforms[ 'cameraProjectionMatrix' ].value.copy( this.camera.projectionMatrix );
		this.ssrMaterial.uniforms[ 'cameraInverseProjectionMatrix' ].value.copy( this.camera.projectionMatrixInverse );

		// normal material

		this.normalMaterial = new MeshNormalMaterial();
		this.normalMaterial.blending = NoBlending;

		// metalnessOn material

		this.metalnessOnMaterial = new MeshBasicMaterial( {
			color: 'white'
		} );

		// metalnessOff material

		this.metalnessOffMaterial = new MeshBasicMaterial( {
			color: 'black'
		} );

		// blur material

		this.blurMaterial = new ShaderMaterial( {
			defines: Object.assign( {}, SSRBlurShader.defines ),
			uniforms: UniformsUtils.clone( SSRBlurShader.uniforms ),
			vertexShader: SSRBlurShader.vertexShader,
			fragmentShader: SSRBlurShader.fragmentShader
		} );
		this.blurMaterial.uniforms[ 'tDiffuse' ].value = this.ssrRenderTarget.texture;
		this.blurMaterial.uniforms[ 'resolution' ].value.set( this.width, this.height );

		// blur material 2

		this.blurMaterial2 = new ShaderMaterial( {
			defines: Object.assign( {}, SSRBlurShader.defines ),
			uniforms: UniformsUtils.clone( SSRBlurShader.uniforms ),
			vertexShader: SSRBlurShader.vertexShader,
			fragmentShader: SSRBlurShader.fragmentShader
		} );
		this.blurMaterial2.uniforms[ 'tDiffuse' ].value = this.blurRenderTarget.texture;
		this.blurMaterial2.uniforms[ 'resolution' ].value.set( this.width, this.height );

		// // blur material 3

		// this.blurMaterial3 = new ShaderMaterial({
		//   defines: Object.assign({}, SSRBlurShader.defines),
		//   uniforms: UniformsUtils.clone(SSRBlurShader.uniforms),
		//   vertexShader: SSRBlurShader.vertexShader,
		//   fragmentShader: SSRBlurShader.fragmentShader
		// });
		// this.blurMaterial3.uniforms['tDiffuse'].value = this.blurRenderTarget2.texture;
		// this.blurMaterial3.uniforms['resolution'].value.set(this.width, this.height);

		// material for rendering the depth

		this.depthRenderMaterial = new ShaderMaterial( {
			defines: Object.assign( {}, SSRDepthShader.defines ),
			uniforms: UniformsUtils.clone( SSRDepthShader.uniforms ),
			vertexShader: SSRDepthShader.vertexShader,
			fragmentShader: SSRDepthShader.fragmentShader,
			blending: NoBlending
		} );
		this.depthRenderMaterial.uniforms[ 'tDepth' ].value = this.beautyRenderTarget.depthTexture;
		this.depthRenderMaterial.uniforms[ 'cameraNear' ].value = this.camera.near;
		this.depthRenderMaterial.uniforms[ 'cameraFar' ].value = this.camera.far;

		// material for rendering the content of a render target

		this.copyMaterial = new ShaderMaterial( {
			uniforms: UniformsUtils.clone( CopyShader.uniforms ),
			vertexShader: CopyShader.vertexShader,
			fragmentShader: CopyShader.fragmentShader,
			transparent: true,
			depthTest: false,
			depthWrite: false,
			blendSrc: SrcAlphaFactor,
			blendDst: OneMinusSrcAlphaFactor,
			blendEquation: AddEquation,
			blendSrcAlpha: SrcAlphaFactor,
			blendDstAlpha: OneMinusSrcAlphaFactor,
			blendEquationAlpha: AddEquation,
			// premultipliedAlpha:true,
		} );

		this.fsQuad = new FullScreenQuad( null );

		this.originalClearColor = new Color();

	}
Constructs a new SSR pass.

@param {SSRPass~Options} options - The pass options.