Realistic fork of Screen Space Reflections implementation from Threejs Examples

ssrshader.js

import {
	Matrix4,
	Vector2,
	AddEquation,
	Color,
	NormalBlending,
	DepthTexture,
	SrcAlphaFactor,
	OneMinusSrcAlphaFactor,
	MeshNormalMaterial,
	MeshBasicMaterial,
	NearestFilter,
	NoBlending,
	ShaderMaterial,
	UniformsUtils,
	UnsignedShortType,
	WebGLRenderTarget,
	HalfFloatType,
} from 'three';
import { Pass, FullScreenQuad } from './Pass.js';
import { CopyShader } from '../shaders/CopyShader.js';

/**
 * References:
 * https://lettier.github.io/3d-game-shaders-for-beginners/screen-space-reflection.html
 * https://www.shadertoy.com/view/XfVGD1
 */

const SSRShader = {

	name: 'SSRShader',

	defines: {
		MAX_STEP: 0,
		PERSPECTIVE_CAMERA: true,
		DISTANCE_ATTENUATION: true,
		FRESNEL: true,
		INFINITE_THICK: false,
		SELECTIVE: false,
	},

	uniforms: {

		'tDiffuse': { value: null },
		'tNormal': { value: null },
		'tMetalness': { value: null },
		'tDepth': { value: null },
		'tAlbedo': { value: null },
		'tRoughness': { value: null },
		'cameraNear': { value: null },
		'cameraFar': { value: null },
		'resolution': { value: new Vector2() },
		'cameraProjectionMatrix': { value: new Matrix4() },
		'cameraInverseProjectionMatrix': { value: new Matrix4() },
		'opacity': { value: 1 },
		'maxDistance': { value: 180 },
		'cameraRange': { value: 0 },
		'thickness': { value: .018 }

	},

	vertexShader: /* glsl */`

		varying vec2 vUv;

		void main() {

			vUv = uv;

			gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

		}

	`,

	fragmentShader: /* glsl */`
		// precision highp float;
		precision highp sampler2D;
		varying vec2 vUv;
		uniform sampler2D tDepth;
		uniform sampler2D tNormal;
		uniform sampler2D tMetalness;
		uniform sampler2D tDiffuse;
                uniform sampler2D tRoughness;
		uniform sampler2D tAlbedo;
		uniform float cameraRange;
		uniform vec2 resolution;
		uniform float opacity;
		uniform float cameraNear;
		uniform float cameraFar;
		uniform float maxDistance;
		uniform float thickness;
		uniform mat4 cameraProjectionMatrix;
		uniform mat4 cameraInverseProjectionMatrix;
		#include <packing>
                // from https://www.shadertoy.com/view/XfVGD1
                vec4 sampleBlur(in sampler2D iSampler, in vec2 uv, in float roughness)
                {
                    float blur = roughness * 6.0;
                    const float s = 0.5;
    
                    // weigh each lod based on the blur amount (0-4)
                    vec4 w = vec4(0.0, 1.0, 2.0, 3.0) * s - blur * s;
                    w = exp(-(w*w));
    
                    w *= 1.0 / (w.x + w.y + w.z + w.w);
    
                    vec4 lodBase = vec4(0.0, 1.0, 2.0, 3.0) + blur;
    
                    vec4 lod0 = textureLod(iSampler, uv, lodBase.x);
                    vec4 lod1 = textureLod(iSampler, uv, lodBase.y);
                    vec4 lod2 = textureLod(iSampler, uv, lodBase.z);
                    vec4 lod3 = textureLod(iSampler, uv, lodBase.w);
    
                    return lod0 * w.x 
                        + lod1 * w.y 
                        + lod2 * w.z 
                        + lod3 * w.w;
                }
    
		float pointToLineDistance(vec3 x0, vec3 x1, vec3 x2) {
			//x0: point, x1: linePointA, x2: linePointB
			//https://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html
			return length(cross(x0-x1,x0-x2))/length(x2-x1);
		}
		float pointPlaneDistance(vec3 point,vec3 planePoint,vec3 planeNormal){
			// https://mathworld.wolfram.com/Point-PlaneDistance.html
			//// https://en.wikipedia.org/wiki/Plane_(geometry)
			//// http://paulbourke.net/geometry/pointlineplane/
			float a=planeNormal.x,b=planeNormal.y,c=planeNormal.z;
			float x0=point.x,y0=point.y,z0=point.z;
			float x=planePoint.x,y=planePoint.y,z=planePoint.z;
			float d=-(a*x+b*y+c*z);
			float distance=(a*x0+b*y0+c*z0+d)/sqrt(a*a+b*b+c*c);
			return distance;
		}
		float getDepth( const in vec2 uv ) {
			return texture2D( tDepth, uv ).x;
		}
		float getViewZ( const in float depth ) {
			#ifdef PERSPECTIVE_CAMERA
				return perspectiveDepthToViewZ( depth, cameraNear, cameraFar );
			#else
				return orthographicDepthToViewZ( depth, cameraNear, cameraFar );
			#endif
		}
		vec3 getViewPosition( const in vec2 uv, const in float depth/*clip space*/, const in float clipW ) {
			vec4 clipPosition = vec4( ( vec3( uv, depth ) - 0.5 ) * 2.0, 1.0 );//ndc
			clipPosition *= clipW; //clip
			return ( cameraInverseProjectionMatrix * clipPosition ).xyz;//view
		}
		vec3 getViewNormal( const in vec2 uv ) {
			return unpackRGBToNormal( texture2D( tNormal, uv ).xyz );
		}
		vec2 viewPositionToXY(vec3 viewPosition){
			vec2 xy;
			vec4 clip=cameraProjectionMatrix*vec4(viewPosition,1);
			xy=clip.xy;//clip
			float clipW=clip.w;
			xy/=clipW;//NDC
			xy=(xy+1.)/2.;//uv
			xy*=resolution;//screen
			return xy;
		}
		
		void main(){

		        float metalness=texture2D(tMetalness,vUv).r;

			float depth = getDepth( vUv );
			float viewZ = getViewZ( depth );
			if(-viewZ>=cameraFar) return;

			float clipW = cameraProjectionMatrix[2][3] * viewZ+cameraProjectionMatrix[3][3];
			vec3 viewPosition=getViewPosition( vUv, depth, clipW );

			vec2 d0=gl_FragCoord.xy;
			vec2 d1;

			vec3 viewNormal=getViewNormal( vUv );

			#ifdef PERSPECTIVE_CAMERA
				vec3 viewIncidentDir=normalize(viewPosition);
				vec3 viewReflectDir=reflect(viewIncidentDir,viewNormal);
			#else
				vec3 viewIncidentDir=vec3(0,0,-1);
				vec3 viewReflectDir=reflect(viewIncidentDir,viewNormal);
			#endif

			float maxReflectRayLen=maxDistance/dot(-viewIncidentDir,viewNormal);
			// dot(a,b)==length(a)*length(b)*cos(theta) // https://www.mathsisfun.com/algebra/vectors-dot-product.html
			// if(a.isNormalized&&b.isNormalized) dot(a,b)==cos(theta)
			// maxDistance/maxReflectRayLen=cos(theta)
			// maxDistance/maxReflectRayLen==dot(a,b)
			// maxReflectRayLen==maxDistance/dot(a,b)

			vec3 d1viewPosition=viewPosition+viewReflectDir*maxReflectRayLen;
			#ifdef PERSPECTIVE_CAMERA
				if(d1viewPosition.z>-cameraNear){
					//https://tutorial.math.lamar.edu/Classes/CalcIII/EqnsOfLines.aspx
					float t=(-cameraNear-viewPosition.z)/viewReflectDir.z;
					d1viewPosition=viewPosition+viewReflectDir*t;
				}
			#endif
			d1=viewPositionToXY(d1viewPosition);

			float totalLen=length(d1-d0);
			float xLen=d1.x-d0.x;
			float yLen=d1.y-d0.y;
			float totalStep=max(abs(xLen),abs(yLen));
			float xSpan=xLen/totalStep;
			float ySpan=yLen/totalStep;
			for(float i=0.;i<float(MAX_STEP);i++){
				if(i>=totalStep) break;
				vec2 xy=vec2(d0.x+i*xSpan,d0.y+i*ySpan);
				if(xy.x<0.||xy.x>resolution.x||xy.y<0.||xy.y>resolution.y) break;
				float s=length(xy-d0)/totalLen;
				vec2 uv=xy/resolution;

				float d = getDepth(uv);
				float vZ = getViewZ( d );
				if(-vZ>=cameraFar) continue;
				float cW = cameraProjectionMatrix[2][3] * vZ+cameraProjectionMatrix[3][3];
				vec3 vP=getViewPosition( uv, d, cW );

				#ifdef PERSPECTIVE_CAMERA
					// https://comp.nus.edu.sg/~lowkl/publications/lowk_persp_interp_techrep.pdf
					float recipVPZ=1./viewPosition.z;
					float viewReflectRayZ=1./(recipVPZ+s*(1./d1viewPosition.z-recipVPZ));
				#else
					float viewReflectRayZ=viewPosition.z+s*(d1viewPosition.z-viewPosition.z);
				#endif

				// if(viewReflectRayZ>vZ) continue; // will cause "npm run make-screenshot webgl_postprocessing_ssr" high probability hang.
				// https://github.com/mrdoob/three.js/pull/21539#issuecomment-821061164
				if(viewReflectRayZ<=vZ){

					bool hit;
					#ifdef INFINITE_THICK
						hit=true;
					#else
						float away=pointToLineDistance(vP,viewPosition,d1viewPosition);

						float minThickness;
						vec2 xyNeighbor=xy;
						xyNeighbor.x+=1.;
						vec2 uvNeighbor=xyNeighbor/resolution;
						vec3 vPNeighbor=getViewPosition(uvNeighbor,d,cW);
						minThickness=vPNeighbor.x-vP.x;
						minThickness*=3.;
						float tk=max(minThickness,thickness);

						hit=away<=tk;
					#endif

					if(hit){
						vec3 vN=getViewNormal( uv );
						if(dot(viewReflectDir,vN)>=0.) continue;
						float distance=pointPlaneDistance(vP,viewPosition,viewNormal);
						float op=opacity;
						#ifdef FRESNEL
							float fresnelCoe=(dot(viewIncidentDir,viewReflectDir)+1.)/2.;
							op*=fresnelCoe;
						#endif
                                                float roughness = texture2D(tRoughness,vUv).r;
						vec4 reflectColor = sampleBlur(tDiffuse, uv, roughness) * op;
						vec4 noMetalic = texture2D(tDiffuse, uv) + reflectColor;
						vec4 fullMetallic = reflectColor * texture2D(tAlbedo, vUv);
						gl_FragColor.xyz=mix(noMetallic, fullMetallic, metalness).xyz;
						gl_FragColor.a=1.0;
						break;
					}
				}
			}
		}
	`

};

const SSRDepthShader = {

	name: 'SSRDepthShader',

	defines: {
		'PERSPECTIVE_CAMERA': 1
	},

	uniforms: {

		'tDepth': { value: null },
		'cameraNear': { value: null },
		'cameraFar': { value: null },

	},

	vertexShader: /* glsl */`

		varying vec2 vUv;

		void main() {

			vUv = uv;
			gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

		}

	`,

	fragmentShader: /* glsl */`

		uniform sampler2D tDepth;

		uniform float cameraNear;
		uniform float cameraFar;

		varying vec2 vUv;

		#include <packing>

		float getLinearDepth( const in vec2 uv ) {

			#if PERSPECTIVE_CAMERA == 1

				float fragCoordZ = texture2D( tDepth, uv ).x;
				float viewZ = perspectiveDepthToViewZ( fragCoordZ, cameraNear, cameraFar );
				return viewZToOrthographicDepth( viewZ, cameraNear, cameraFar );

			#else

				return texture2D( tDepth, uv ).x;

			#endif

		}

		void main() {

			float depth = getLinearDepth( vUv );
			float d = 1.0 - depth;
			// d=(d-.999)*1000.;
			gl_FragColor = vec4( vec3( d ), 1.0 );

		}

	`

};

class SSRPass extends Pass {

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

		super();

		this.width = ( width !== undefined ) ? width : 512;
		this.height = ( height !== undefined ) ? height : 512;

		this.clear = true;

		this.renderer = renderer;
		this.scene = scene;
		this.camera = camera;
		this.groundReflector = groundReflector;

		this.opacity = 1.0;
		this.output = 0;

		this.maxDistance = SSRShader.uniforms.maxDistance.value;
		this.thickness = SSRShader.uniforms.thickness.value;

		this.tempColor = new Color();

		this._selects = selects;
		this.selective = Array.isArray( this._selects );

		this._bouncing = bouncing;
		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;

				}

			}
		} );

		this.blur = true;

		this._distanceAttenuation = SSRShader.defines.DISTANCE_ATTENUATION;
		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;
		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;
		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,
		} );

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

		// 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.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[ 'tRoughness' ].value = this.roughnessRenderTarget.texture;
		this.ssrMaterial.uniforms[ 'tAlbedo' ].value = this.albedoRenderTarget.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

		// blur material 2

		// // 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();

	}

	dispose() {

		// dispose render targets

		this.beautyRenderTarget.dispose();
		this.prevRenderTarget.dispose();
		this.normalRenderTarget.dispose();
		this.metalnessRenderTarget.dispose();
		this.roughnessRenderTarget.dispose();
		this.albedoRenderTarget.dispose();
		this.ssrRenderTarget.dispose();
		// this.blurRenderTarget3.dispose();

		// dispose materials

		this.normalMaterial.dispose();
		this.metalnessOnMaterial.dispose();
		this.metalnessOffMaterial.dispose();
		this.copyMaterial.dispose();
		this.depthRenderMaterial.dispose();

		// dipsose full screen quad

		this.fsQuad.dispose();

	}

	render( renderer, writeBuffer /*, readBuffer, deltaTime, maskActive */ ) {

		// render beauty and depth

		renderer.setRenderTarget( this.beautyRenderTarget );
		renderer.clear();
		if ( this.groundReflector ) {

			this.groundReflector.visible = false;
			this.groundReflector.doRender( this.renderer, this.scene, this.camera );
			this.groundReflector.visible = true;

		}

		renderer.render( this.scene, this.camera );
		if ( this.groundReflector ) this.groundReflector.visible = false;

		// render normals

		this.renderOverride( renderer, this.normalMaterial, this.normalRenderTarget, 0, 0 );

		// render metalnesses

		if ( this.selective ) {

			this.renderMetalness( renderer, this.metalnessOnMaterial, this.metalnessRenderTarget, 0, 0 );

		}

		// render SSR

		this.ssrMaterial.uniforms[ 'opacity' ].value = this.opacity;
		this.ssrMaterial.uniforms[ 'maxDistance' ].value = this.maxDistance;
		this.ssrMaterial.uniforms[ 'thickness' ].value = this.thickness;
		this.renderPass( renderer, this.ssrMaterial, this.ssrRenderTarget );

		// output result to screen

		switch ( this.output ) {

			case SSRPass.OUTPUT.Default:
			case SSRPass.OUTPUT.SSR:
				this.copyMaterial.uniforms[ 'tDiffuse' ].value = this.ssrRenderTarget.texture;
				this.copyMaterial.blending = NoBlending;
				this.renderPass( renderer, this.copyMaterial, this.renderToScreen ? null : writeBuffer );

				if ( this.bouncing ) {

					this.copyMaterial.uniforms[ 'tDiffuse' ].value = this.beautyRenderTarget.texture;
					this.copyMaterial.blending = NoBlending;
					this.renderPass( renderer, this.copyMaterial, this.prevRenderTarget );

					this.copyMaterial.uniforms[ 'tDiffuse' ].value = this.ssrRenderTarget.texture;
					this.copyMaterial.blending = NormalBlending;
					this.renderPass( renderer, this.copyMaterial, this.prevRenderTarget );

				}

				break;

			case SSRPass.OUTPUT.Beauty:

				this.copyMaterial.uniforms[ 'tDiffuse' ].value = this.beautyRenderTarget.texture;
				this.copyMaterial.blending = NoBlending;
				this.renderPass( renderer, this.copyMaterial, this.renderToScreen ? null : writeBuffer );

				break;

			case SSRPass.OUTPUT.Depth:

				this.renderPass( renderer, this.depthRenderMaterial, this.renderToScreen ? null : writeBuffer );

				break;

			case SSRPass.OUTPUT.Normal:

				this.copyMaterial.uniforms[ 'tDiffuse' ].value = this.normalRenderTarget.texture;
				this.copyMaterial.blending = NoBlending;
				this.renderPass( renderer, this.copyMaterial, this.renderToScreen ? null : writeBuffer );

				break;

			case SSRPass.OUTPUT.Metalness:

				this.copyMaterial.uniforms[ 'tDiffuse' ].value = this.metalnessRenderTarget.texture;
				this.copyMaterial.blending = NoBlending;
				this.renderPass( renderer, this.copyMaterial, this.renderToScreen ? null : writeBuffer );

				break;

			default:
				console.warn( 'THREE.SSRPass: Unknown output type.' );

		}

	}

	renderPass( renderer, passMaterial, renderTarget, clearColor, clearAlpha ) {

		// save original state
		this.originalClearColor.copy( renderer.getClearColor( this.tempColor ) );
		const originalClearAlpha = renderer.getClearAlpha( this.tempColor );
		const originalAutoClear = renderer.autoClear;

		renderer.setRenderTarget( renderTarget );

		// setup pass state
		renderer.autoClear = false;
		if ( ( clearColor !== undefined ) && ( clearColor !== null ) ) {

			renderer.setClearColor( clearColor );
			renderer.setClearAlpha( clearAlpha || 0.0 );
			renderer.clear();

		}

		this.fsQuad.material = passMaterial;
		this.fsQuad.render( renderer );

		// restore original state
		renderer.autoClear = originalAutoClear;
		renderer.setClearColor( this.originalClearColor );
		renderer.setClearAlpha( originalClearAlpha );

	}

	renderOverride( renderer, overrideMaterial, renderTarget, clearColor, clearAlpha ) {

		this.originalClearColor.copy( renderer.getClearColor( this.tempColor ) );
		const originalClearAlpha = renderer.getClearAlpha( this.tempColor );
		const originalAutoClear = renderer.autoClear;

		renderer.setRenderTarget( renderTarget );
		renderer.autoClear = false;

		clearColor = overrideMaterial.clearColor || clearColor;
		clearAlpha = overrideMaterial.clearAlpha || clearAlpha;

		if ( ( clearColor !== undefined ) && ( clearColor !== null ) ) {

			renderer.setClearColor( clearColor );
			renderer.setClearAlpha( clearAlpha || 0.0 );
			renderer.clear();

		}

		this.scene.overrideMaterial = overrideMaterial;
		renderer.render( this.scene, this.camera );
		this.scene.overrideMaterial = null;

		// restore original state

		renderer.autoClear = originalAutoClear;
		renderer.setClearColor( this.originalClearColor );
		renderer.setClearAlpha( originalClearAlpha );

	}

	renderMetalness( renderer, overrideMaterial, renderTarget, clearColor, clearAlpha ) {

		this.originalClearColor.copy( renderer.getClearColor( this.tempColor ) );
		const originalClearAlpha = renderer.getClearAlpha( this.tempColor );
		const originalAutoClear = renderer.autoClear;

		renderer.setRenderTarget( renderTarget );
		renderer.autoClear = false;

		clearColor = overrideMaterial.clearColor || clearColor;
		clearAlpha = overrideMaterial.clearAlpha || clearAlpha;

		if ( ( clearColor !== undefined ) && ( clearColor !== null ) ) {

			renderer.setClearColor( clearColor );
			renderer.setClearAlpha( clearAlpha || 0.0 );
			renderer.clear();

		}

		this.scene.traverseVisible( child => {

			child._SSRPassBackupMaterial = child.material;
			if ( this._selects.includes( child ) ) {

				child.material = this.metalnessOnMaterial;

			} else {

				child.material = this.metalnessOffMaterial;

			}

		} );
		renderer.render( this.scene, this.camera );
		this.scene.traverseVisible( child => {

			child.material = child._SSRPassBackupMaterial;

		} );

		// restore original state

		renderer.autoClear = originalAutoClear;
		renderer.setClearColor( this.originalClearColor );
		renderer.setClearAlpha( originalClearAlpha );

	}

	setSize( width, height ) {

		this.width = width;
		this.height = height;

		this.ssrMaterial.defines.MAX_STEP = Math.sqrt( width * width + height * height );
		this.ssrMaterial.needsUpdate = true;
		this.beautyRenderTarget.setSize( width, height );
		this.prevRenderTarget.setSize( width, height );
		this.ssrRenderTarget.setSize( width, height );
		this.normalRenderTarget.setSize( width, height );
		this.metalnessRenderTarget.setSize( width, height );
		this.blurRenderTarget.setSize( width, height );
		this.blurRenderTarget2.setSize( width, height );
		// this.blurRenderTarget3.setSize(width, height);

		this.ssrMaterial.uniforms[ 'resolution' ].value.set( width, height );
		this.ssrMaterial.uniforms[ 'cameraProjectionMatrix' ].value.copy( this.camera.projectionMatrix );
		this.ssrMaterial.uniforms[ 'cameraInverseProjectionMatrix' ].value.copy( this.camera.projectionMatrixInverse );

		this.blurMaterial.uniforms[ 'resolution' ].value.set( width, height );
		this.blurMaterial2.uniforms[ 'resolution' ].value.set( width, height );

	}

}

SSRPass.OUTPUT = {
	'Default': 0,
	'SSR': 1,
	'Beauty': 3,
	'Depth': 4,
	'Normal': 5,
	'Metalness': 7,
};

export { SSRPass };