import { Matrix4, Vector2 } from 'three'; /** * References: * http://john-chapman-graphics.blogspot.com/2013/01/ssao-tutorial.html * https://learnopengl.com/Advanced-Lighting/SSAO * https://github.com/McNopper/OpenGL/blob/master/Example28/shader/ssao.frag.glsl */ const SSAOShader = { defines: { 'PERSPECTIVE_CAMERA': 1, 'KERNEL_SIZE': 32 }, uniforms: { 'tDiffuse': { value: null }, 'tNormal': { value: null }, 'tDepth': { value: null }, 'tNoise': { value: null }, 'kernel': { value: null }, 'cameraNear': { value: null }, 'cameraFar': { value: null }, 'resolution': { value: new Vector2() }, 'cameraProjectionMatrix': { value: new Matrix4() }, 'cameraInverseProjectionMatrix': { value: new Matrix4() }, 'kernelRadius': { value: 8 }, 'minDistance': { value: 0.005 }, 'maxDistance': { value: 0.05 }, }, vertexShader: /* glsl */` varying vec2 vUv; void main() { vUv = uv; gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 ); }`, fragmentShader: /* glsl */` uniform sampler2D tDiffuse; uniform sampler2D tNormal; uniform sampler2D tDepth; uniform sampler2D tNoise; uniform vec3 kernel[ KERNEL_SIZE ]; uniform vec2 resolution; uniform float cameraNear; uniform float cameraFar; uniform mat4 cameraProjectionMatrix; uniform mat4 cameraInverseProjectionMatrix; uniform float kernelRadius; uniform float minDistance; // avoid artifacts caused by neighbour fragments with minimal depth difference uniform float maxDistance; // avoid the influence of fragments which are too far away varying vec2 vUv; #include float getDepth( const in vec2 screenPosition ) { return texture2D( tDepth, screenPosition ).x; } float getLinearDepth( const in vec2 screenPosition ) { #if PERSPECTIVE_CAMERA == 1 float fragCoordZ = texture2D( tDepth, screenPosition ).x; float viewZ = perspectiveDepthToViewZ( fragCoordZ, cameraNear, cameraFar ); return viewZToOrthographicDepth( viewZ, cameraNear, cameraFar ); #else return texture2D( tDepth, screenPosition ).x; #endif } float getViewZ( const in float depth ) { #if PERSPECTIVE_CAMERA == 1 return perspectiveDepthToViewZ( depth, cameraNear, cameraFar ); #else return orthographicDepthToViewZ( depth, cameraNear, cameraFar ); #endif } vec3 getViewPosition( const in vec2 screenPosition, const in float depth, const in float viewZ ) { float clipW = cameraProjectionMatrix[2][3] * viewZ + cameraProjectionMatrix[3][3]; vec4 clipPosition = vec4( ( vec3( screenPosition, depth ) - 0.5 ) * 2.0, 1.0 ); clipPosition *= clipW; // unprojection. return ( cameraInverseProjectionMatrix * clipPosition ).xyz; } vec3 getViewNormal( const in vec2 screenPosition ) { return unpackRGBToNormal( texture2D( tNormal, screenPosition ).xyz ); } void main() { float depth = getDepth( vUv ); float viewZ = getViewZ( depth ); vec3 viewPosition = getViewPosition( vUv, depth, viewZ ); vec3 viewNormal = getViewNormal( vUv ); vec2 noiseScale = vec2( resolution.x / 4.0, resolution.y / 4.0 ); vec3 random = vec3( texture2D( tNoise, vUv * noiseScale ).r ); // compute matrix used to reorient a kernel vector vec3 tangent = normalize( random - viewNormal * dot( random, viewNormal ) ); vec3 bitangent = cross( viewNormal, tangent ); mat3 kernelMatrix = mat3( tangent, bitangent, viewNormal ); float occlusion = 0.0; for ( int i = 0; i < KERNEL_SIZE; i ++ ) { vec3 sampleVector = kernelMatrix * kernel[ i ]; // reorient sample vector in view space vec3 samplePoint = viewPosition + ( sampleVector * kernelRadius ); // calculate sample point vec4 samplePointNDC = cameraProjectionMatrix * vec4( samplePoint, 1.0 ); // project point and calculate NDC samplePointNDC /= samplePointNDC.w; vec2 samplePointUv = samplePointNDC.xy * 0.5 + 0.5; // compute uv coordinates float realDepth = getLinearDepth( samplePointUv ); // get linear depth from depth texture float sampleDepth = viewZToOrthographicDepth( samplePoint.z, cameraNear, cameraFar ); // compute linear depth of the sample view Z value float delta = sampleDepth - realDepth; if ( delta > minDistance && delta < maxDistance ) { // if fragment is before sample point, increase occlusion occlusion += 1.0; } } occlusion = clamp( occlusion / float( KERNEL_SIZE ), 0.0, 1.0 ); gl_FragColor = vec4( vec3( 1.0 - occlusion ), 1.0 ); }` }; const SSAODepthShader = { defines: { 'PERSPECTIVE_CAMERA': 1 }, uniforms: { 'tDepth': { value: null }, 'cameraNear': { value: null }, 'cameraFar': { value: null }, }, vertexShader: `varying vec2 vUv; void main() { vUv = uv; gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 ); }`, fragmentShader: `uniform sampler2D tDepth; uniform float cameraNear; uniform float cameraFar; varying vec2 vUv; #include float getLinearDepth( const in vec2 screenPosition ) { #if PERSPECTIVE_CAMERA == 1 float fragCoordZ = texture2D( tDepth, screenPosition ).x; float viewZ = perspectiveDepthToViewZ( fragCoordZ, cameraNear, cameraFar ); return viewZToOrthographicDepth( viewZ, cameraNear, cameraFar ); #else return texture2D( tDepth, screenPosition ).x; #endif } void main() { float depth = getLinearDepth( vUv ); gl_FragColor = vec4( vec3( 1.0 - depth ), 1.0 ); }` }; const SSAOBlurShader = { uniforms: { 'tDiffuse': { value: null }, 'resolution': { value: new Vector2() } }, vertexShader: `varying vec2 vUv; void main() { vUv = uv; gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 ); }`, fragmentShader: `uniform sampler2D tDiffuse; uniform vec2 resolution; varying vec2 vUv; void main() { vec2 texelSize = ( 1.0 / resolution ); float result = 0.0; for ( int i = - 2; i <= 2; i ++ ) { for ( int j = - 2; j <= 2; j ++ ) { vec2 offset = ( vec2( float( i ), float( j ) ) ) * texelSize; result += texture2D( tDiffuse, vUv + offset ).r; } } gl_FragColor = vec4( vec3( result / ( 5.0 * 5.0 ) ), 1.0 ); }` }; export { SSAOShader, SSAODepthShader, SSAOBlurShader };