three.js/examples/js/objects/ReflectorForSSRPass.js

( function () {

	class ReflectorForSSRPass extends THREE.Mesh {

		constructor( geometry, options = {} ) {

			super( geometry );
			this.isReflectorForSSRPass = true;
			this.type = 'ReflectorForSSRPass';
			const scope = this;
			const color = options.color !== undefined ? new THREE.Color( options.color ) : new THREE.Color( 0x7F7F7F );
			const textureWidth = options.textureWidth || 512;
			const textureHeight = options.textureHeight || 512;
			const clipBias = options.clipBias || 0;
			const shader = options.shader || ReflectorForSSRPass.ReflectorShader;
			const useDepthTexture = options.useDepthTexture === true;
			const yAxis = new THREE.Vector3( 0, 1, 0 );
			const vecTemp0 = new THREE.Vector3();
			const vecTemp1 = new THREE.Vector3(); //

			scope.needsUpdate = false;
			scope.maxDistance = ReflectorForSSRPass.ReflectorShader.uniforms.maxDistance.value;
			scope.opacity = ReflectorForSSRPass.ReflectorShader.uniforms.opacity.value;
			scope.color = color;
			scope.resolution = options.resolution || new THREE.Vector2( window.innerWidth, window.innerHeight );
			scope._distanceAttenuation = ReflectorForSSRPass.ReflectorShader.defines.DISTANCE_ATTENUATION;
			Object.defineProperty( scope, 'distanceAttenuation', {
				get() {

					return scope._distanceAttenuation;

				},

				set( val ) {

					if ( scope._distanceAttenuation === val ) return;
					scope._distanceAttenuation = val;
					scope.material.defines.DISTANCE_ATTENUATION = val;
					scope.material.needsUpdate = true;

				}

			} );
			scope._fresnel = ReflectorForSSRPass.ReflectorShader.defines.FRESNEL;
			Object.defineProperty( scope, 'fresnel', {
				get() {

					return scope._fresnel;

				},

				set( val ) {

					if ( scope._fresnel === val ) return;
					scope._fresnel = val;
					scope.material.defines.FRESNEL = val;
					scope.material.needsUpdate = true;

				}

			} );
			const normal = new THREE.Vector3();
			const reflectorWorldPosition = new THREE.Vector3();
			const cameraWorldPosition = new THREE.Vector3();
			const rotationMatrix = new THREE.Matrix4();
			const lookAtPosition = new THREE.Vector3( 0, 0, - 1 );
			const view = new THREE.Vector3();
			const target = new THREE.Vector3();
			const textureMatrix = new THREE.Matrix4();
			const virtualCamera = new THREE.PerspectiveCamera();
			let depthTexture;

			if ( useDepthTexture ) {

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

			}

			const parameters = {
				depthTexture: useDepthTexture ? depthTexture : null
			};
			const renderTarget = new THREE.WebGLRenderTarget( textureWidth, textureHeight, parameters );
			const material = new THREE.ShaderMaterial( {
				transparent: useDepthTexture,
				defines: Object.assign( {}, ReflectorForSSRPass.ReflectorShader.defines, {
					useDepthTexture
				} ),
				uniforms: THREE.UniformsUtils.clone( shader.uniforms ),
				fragmentShader: shader.fragmentShader,
				vertexShader: shader.vertexShader
			} );
			material.uniforms[ 'tDiffuse' ].value = renderTarget.texture;
			material.uniforms[ 'color' ].value = scope.color;
			material.uniforms[ 'textureMatrix' ].value = textureMatrix;

			if ( useDepthTexture ) {

				material.uniforms[ 'tDepth' ].value = renderTarget.depthTexture;

			}

			this.material = material;
			const globalPlane = new THREE.Plane( new THREE.Vector3( 0, 1, 0 ), clipBias );
			const globalPlanes = [ globalPlane ];

			this.doRender = function ( renderer, scene, camera ) {

				material.uniforms[ 'maxDistance' ].value = scope.maxDistance;
				material.uniforms[ 'color' ].value = scope.color;
				material.uniforms[ 'opacity' ].value = scope.opacity;
				vecTemp0.copy( camera.position ).normalize();
				vecTemp1.copy( vecTemp0 ).reflect( yAxis );
				material.uniforms[ 'fresnelCoe' ].value = ( vecTemp0.dot( vecTemp1 ) + 1. ) / 2.; // TODO: Also need to use glsl viewPosition and viewNormal per pixel.

				reflectorWorldPosition.setFromMatrixPosition( scope.matrixWorld );
				cameraWorldPosition.setFromMatrixPosition( camera.matrixWorld );
				rotationMatrix.extractRotation( scope.matrixWorld );
				normal.set( 0, 0, 1 );
				normal.applyMatrix4( rotationMatrix );
				view.subVectors( reflectorWorldPosition, cameraWorldPosition ); // Avoid rendering when reflector is facing away

				if ( view.dot( normal ) > 0 ) return;
				view.reflect( normal ).negate();
				view.add( reflectorWorldPosition );
				rotationMatrix.extractRotation( camera.matrixWorld );
				lookAtPosition.set( 0, 0, - 1 );
				lookAtPosition.applyMatrix4( rotationMatrix );
				lookAtPosition.add( cameraWorldPosition );
				target.subVectors( reflectorWorldPosition, lookAtPosition );
				target.reflect( normal ).negate();
				target.add( reflectorWorldPosition );
				virtualCamera.position.copy( view );
				virtualCamera.up.set( 0, 1, 0 );
				virtualCamera.up.applyMatrix4( rotationMatrix );
				virtualCamera.up.reflect( normal );
				virtualCamera.lookAt( target );
				virtualCamera.far = camera.far; // Used in WebGLBackground

				virtualCamera.updateMatrixWorld();
				virtualCamera.projectionMatrix.copy( camera.projectionMatrix );
				material.uniforms[ 'virtualCameraNear' ].value = camera.near;
				material.uniforms[ 'virtualCameraFar' ].value = camera.far;
				material.uniforms[ 'virtualCameraMatrixWorld' ].value = virtualCamera.matrixWorld;
				material.uniforms[ 'virtualCameraProjectionMatrix' ].value = camera.projectionMatrix;
				material.uniforms[ 'virtualCameraProjectionMatrixInverse' ].value = camera.projectionMatrixInverse;
				material.uniforms[ 'resolution' ].value = scope.resolution; // Update the texture matrix

				textureMatrix.set( 0.5, 0.0, 0.0, 0.5, 0.0, 0.5, 0.0, 0.5, 0.0, 0.0, 0.5, 0.5, 0.0, 0.0, 0.0, 1.0 );
				textureMatrix.multiply( virtualCamera.projectionMatrix );
				textureMatrix.multiply( virtualCamera.matrixWorldInverse );
				textureMatrix.multiply( scope.matrixWorld ); // Render

				renderTarget.texture.encoding = renderer.outputEncoding; // scope.visible = false;

				const currentRenderTarget = renderer.getRenderTarget();
				const currentXrEnabled = renderer.xr.enabled;
				const currentShadowAutoUpdate = renderer.shadowMap.autoUpdate;
				const currentClippingPlanes = renderer.clippingPlanes;
				renderer.xr.enabled = false; // Avoid camera modification

				renderer.shadowMap.autoUpdate = false; // Avoid re-computing shadows

				renderer.clippingPlanes = globalPlanes;
				renderer.setRenderTarget( renderTarget );
				renderer.state.buffers.depth.setMask( true ); // make sure the depth buffer is writable so it can be properly cleared, see #18897

				if ( renderer.autoClear === false ) renderer.clear();
				renderer.render( scene, virtualCamera );
				renderer.xr.enabled = currentXrEnabled;
				renderer.shadowMap.autoUpdate = currentShadowAutoUpdate;
				renderer.clippingPlanes = currentClippingPlanes;
				renderer.setRenderTarget( currentRenderTarget ); // Restore viewport

				const viewport = camera.viewport;

				if ( viewport !== undefined ) {

					renderer.state.viewport( viewport );

				} // scope.visible = true;

			};

			this.getRenderTarget = function () {

				return renderTarget;

			};

		}

	}

	ReflectorForSSRPass.ReflectorShader = {
		defines: {
			DISTANCE_ATTENUATION: true,
			FRESNEL: true
		},
		uniforms: {
			color: {
				value: null
			},
			tDiffuse: {
				value: null
			},
			tDepth: {
				value: null
			},
			textureMatrix: {
				value: new THREE.Matrix4()
			},
			maxDistance: {
				value: 180
			},
			opacity: {
				value: 0.5
			},
			fresnelCoe: {
				value: null
			},
			virtualCameraNear: {
				value: null
			},
			virtualCameraFar: {
				value: null
			},
			virtualCameraProjectionMatrix: {
				value: new THREE.Matrix4()
			},
			virtualCameraMatrixWorld: {
				value: new THREE.Matrix4()
			},
			virtualCameraProjectionMatrixInverse: {
				value: new THREE.Matrix4()
			},
			resolution: {
				value: new THREE.Vector2()
			}
		},
		vertexShader:
  /* glsl */
  `
		uniform mat4 textureMatrix;
		varying vec4 vUv;

		void main() {

			vUv = textureMatrix * vec4( position, 1.0 );

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

		}`,
		fragmentShader:
  /* glsl */
  `
		uniform vec3 color;
		uniform sampler2D tDiffuse;
		uniform sampler2D tDepth;
		uniform float maxDistance;
		uniform float opacity;
		uniform float fresnelCoe;
		uniform float virtualCameraNear;
		uniform float virtualCameraFar;
		uniform mat4 virtualCameraProjectionMatrix;
		uniform mat4 virtualCameraProjectionMatrixInverse;
		uniform mat4 virtualCameraMatrixWorld;
		uniform vec2 resolution;
		varying vec4 vUv;
		#include <packing>
		float blendOverlay( float base, float blend ) {
			return( base < 0.5 ? ( 2.0 * base * blend ) : ( 1.0 - 2.0 * ( 1.0 - base ) * ( 1.0 - blend ) ) );
		}
		vec3 blendOverlay( vec3 base, vec3 blend ) {
			return vec3( blendOverlay( base.r, blend.r ), blendOverlay( base.g, blend.g ), blendOverlay( base.b, blend.b ) );
		}
		float getDepth( const in vec2 uv ) {
			return texture2D( tDepth, uv ).x;
		}
		float getViewZ( const in float depth ) {
			return perspectiveDepthToViewZ( depth, virtualCameraNear, virtualCameraFar );
		}
		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 ( virtualCameraProjectionMatrixInverse * clipPosition ).xyz;//view
		}
		void main() {
			vec4 base = texture2DProj( tDiffuse, vUv );
			#ifdef useDepthTexture
				vec2 uv=(gl_FragCoord.xy-.5)/resolution.xy;
				uv.x=1.-uv.x;
				float depth = texture2DProj( tDepth, vUv ).r;
				float viewZ = getViewZ( depth );
				float clipW = virtualCameraProjectionMatrix[2][3] * viewZ+virtualCameraProjectionMatrix[3][3];
				vec3 viewPosition=getViewPosition( uv, depth, clipW );
				vec3 worldPosition=(virtualCameraMatrixWorld*vec4(viewPosition,1)).xyz;
				if(worldPosition.y>maxDistance) discard;
				float op=opacity;
				#ifdef DISTANCE_ATTENUATION
					float ratio=1.-(worldPosition.y/maxDistance);
					float attenuation=ratio*ratio;
					op=opacity*attenuation;
				#endif
				#ifdef FRESNEL
					op*=fresnelCoe;
				#endif
				gl_FragColor = vec4( blendOverlay( base.rgb, color ), op );
			#else
				gl_FragColor = vec4( blendOverlay( base.rgb, color ), 1.0 );
			#endif
		}
	`
	};

	THREE.ReflectorForSSRPass = ReflectorForSSRPass;

} )();