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Created January 26, 2022 20:06
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UnrealBloomPassAlpha.js is a modified version of the three.js UnrealBloomPass that preserves alpha channel functionality.
import {
AdditiveBlending,
Color,
LinearFilter,
MeshBasicMaterial,
RGBAFormat,
ShaderMaterial,
Texture,
UniformsUtils,
Vector2,
Vector3,
WebGLRenderer,
WebGLRenderTarget,
} from "three";
import { Pass, FullScreenQuad } from "three/examples/jsm/postprocessing/Pass";
import { CopyShader } from "three/examples/jsm/shaders/CopyShader.js";
import { LuminosityHighPassShader } from "three/examples/jsm/shaders/LuminosityHighPassShader.js";
/**
* UnrealBloomPass is inspired by the bloom pass of Unreal Engine. It creates a
* mip map chain of bloom textures and blurs them with different radii. Because
* of the weighted combination of mips, and because larger blurs are done on
* higher mips, this effect provides good quality and performance.
*
* Reference:
* - https://docs.unrealengine.com/latest/INT/Engine/Rendering/PostProcessEffects/Bloom/
*/
class UnrealBloomPassAlpha extends Pass {
constructor( resolution, strength, radius, threshold ) {
super();
this.strength = ( strength !== undefined ) ? strength : 1;
this.radius = radius;
this.threshold = threshold;
this.resolution = ( resolution !== undefined ) ? new Vector2( resolution.x, resolution.y ) : new Vector2( 256, 256 );
// create color only once here, reuse it later inside the render function
this.clearColor = new Color(0, 0, 0);
// render targets
const pars = { minFilter: LinearFilter, magFilter: LinearFilter, format: RGBAFormat };
this.renderTargetsHorizontal = [];
this.renderTargetsVertical = [];
this.nMips = 5;
let resx = Math.round(this.resolution.x / 2);
let resy = Math.round(this.resolution.y / 2);
this.renderTargetBright = new WebGLRenderTarget(resx, resy, pars);
this.renderTargetBright.texture.name = "UnrealBloomPass.bright";
this.renderTargetBright.texture.generateMipmaps = false;
for (let i = 0; i < this.nMips; i++) {
const renderTargetHorizonal = new WebGLRenderTarget(resx, resy, pars);
renderTargetHorizonal.texture.name = "UnrealBloomPass.h" + i;
renderTargetHorizonal.texture.generateMipmaps = false;
this.renderTargetsHorizontal.push(renderTargetHorizonal);
const renderTargetVertical = new WebGLRenderTarget(resx, resy, pars);
renderTargetVertical.texture.name = "UnrealBloomPass.v" + i;
renderTargetVertical.texture.generateMipmaps = false;
this.renderTargetsVertical.push(renderTargetVertical);
resx = Math.round(resx / 2);
resy = Math.round(resy / 2);
}
// luminosity high pass material
if (LuminosityHighPassShader === undefined)
console.error("THREE.UnrealBloomPass relies on LuminosityHighPassShader");
const highPassShader = LuminosityHighPassShader;
this.highPassUniforms = UniformsUtils.clone(highPassShader.uniforms);
this.highPassUniforms["luminosityThreshold"].value = threshold;
this.highPassUniforms["smoothWidth"].value = 0.01;
this.materialHighPassFilter = new ShaderMaterial({
uniforms: this.highPassUniforms,
vertexShader: highPassShader.vertexShader,
fragmentShader: highPassShader.fragmentShader,
defines: {},
});
// Gaussian Blur Materials
this.separableBlurMaterials = [];
const kernelSizeArray = [3, 5, 7, 9, 11];
resx = Math.round(this.resolution.x / 2);
resy = Math.round(this.resolution.y / 2);
for (let i = 0; i < this.nMips; i++) {
this.separableBlurMaterials.push(
this.getSeperableBlurMaterial(kernelSizeArray[ i ])
);
this.separableBlurMaterials[ i ].uniforms["texSize"].value = new Vector2(
resx,
resy
);
resx = Math.round(resx / 2);
resy = Math.round(resy / 2);
}
// Composite material
this.compositeMaterial = this.getCompositeMaterial(this.nMips);
this.compositeMaterial.uniforms["blurTexture1"].value =
this.renderTargetsVertical[0].texture;
this.compositeMaterial.uniforms["blurTexture2"].value =
this.renderTargetsVertical[1].texture;
this.compositeMaterial.uniforms["blurTexture3"].value =
this.renderTargetsVertical[2].texture;
this.compositeMaterial.uniforms["blurTexture4"].value =
this.renderTargetsVertical[3].texture;
this.compositeMaterial.uniforms["blurTexture5"].value =
this.renderTargetsVertical[4].texture;
this.compositeMaterial.uniforms["bloomStrength"].value = strength;
this.compositeMaterial.uniforms["bloomRadius"].value = 0.1;
this.compositeMaterial.needsUpdate = true;
const bloomFactors = [1.0, 0.8, 0.6, 0.4, 0.2];
this.compositeMaterial.uniforms["bloomFactors"].value = bloomFactors;
this.bloomTintColors = [
new Vector3(1, 1, 1),
new Vector3(1, 1, 1),
new Vector3(1, 1, 1),
new Vector3(1, 1, 1),
new Vector3(1, 1, 1),
];
this.compositeMaterial.uniforms["bloomTintColors"].value =
this.bloomTintColors;
// copy material
if (CopyShader === undefined) {
console.error("THREE.UnrealBloomPass relies on CopyShader");
}
const copyShader = CopyShader;
this.copyUniforms = UniformsUtils.clone(copyShader.uniforms);
this.copyUniforms["opacity"].value = 1.0;
this.materialCopy = new ShaderMaterial({
uniforms: this.copyUniforms,
vertexShader: copyShader.vertexShader,
fragmentShader: copyShader.fragmentShader,
blending: AdditiveBlending,
depthTest: false,
depthWrite: false,
transparent: true,
});
this.enabled = true;
this.needsSwap = false;
this._oldClearColor = new Color();
this.oldClearAlpha = 1;
this.basic = new MeshBasicMaterial();
this.fsQuad = new FullScreenQuad(null);
}
dispose() {
for (let i = 0; i < this.renderTargetsHorizontal.length; i++) {
this.renderTargetsHorizontal[ i ].dispose();
}
for (let i = 0; i < this.renderTargetsVertical.length; i++) {
this.renderTargetsVertical[ i ].dispose();
}
this.renderTargetBright.dispose();
}
setSize(width, height) {
let resx = Math.round(width / 2);
let resy = Math.round(height / 2);
this.renderTargetBright.setSize(resx, resy);
for (let i = 0; i < this.nMips; i++) {
this.renderTargetsHorizontal[ i ].setSize(resx, resy);
this.renderTargetsVertical[ i ].setSize(resx, resy);
this.separableBlurMaterials[ i ].uniforms["texSize"].value = new Vector2(
resx,
resy
);
resx = Math.round(resx / 2);
resy = Math.round(resy / 2);
}
}
render(renderer, writeBuffer, readBuffer, deltaTime, maskActive) {
renderer.getClearColor(this._oldClearColor);
this.oldClearAlpha = renderer.getClearAlpha();
const oldAutoClear = renderer.autoClear;
renderer.autoClear = false;
renderer.setClearColor(this.clearColor, 0);
if (maskActive) renderer.state.buffers.stencil.setTest(false);
// Render input to screen
if (this.renderToScreen) {
this.fsQuad.material = this.basic;
this.basic.map = readBuffer.texture;
renderer.setRenderTarget(null);
renderer.clear();
this.fsQuad.render(renderer);
}
// 1. Extract Bright Areas
this.highPassUniforms["tDiffuse"].value = readBuffer.texture;
this.highPassUniforms["luminosityThreshold"].value = this.threshold;
this.fsQuad.material = this.materialHighPassFilter;
renderer.setRenderTarget(this.renderTargetBright);
renderer.clear();
this.fsQuad.render(renderer);
// 2. Blur All the mips progressively
let inputRenderTarget = this.renderTargetBright;
for (let i = 0; i < this.nMips; i++) {
this.fsQuad.material = this.separableBlurMaterials[ i ];
this.separableBlurMaterials[ i ].uniforms["colorTexture"].value = inputRenderTarget.texture;
this.separableBlurMaterials[ i ].uniforms["direction"].value = UnrealBloomPassAlpha.BlurDirectionX;
renderer.setRenderTarget(this.renderTargetsHorizontal[ i ] );
renderer.clear();
this.fsQuad.render( renderer );
this.separableBlurMaterials[ i ].uniforms["colorTexture"].value =
this.renderTargetsHorizontal[ i ].texture;
this.separableBlurMaterials[ i ].uniforms["direction"].value = UnrealBloomPassAlpha.BlurDirectionY;
renderer.setRenderTarget(this.renderTargetsVertical[ i ]);
renderer.clear();
this.fsQuad.render(renderer);
inputRenderTarget = this.renderTargetsVertical[ i ];
}
// Composite All the mips
this.fsQuad.material = this.compositeMaterial;
this.compositeMaterial.uniforms["bloomStrength"].value = this.strength;
this.compositeMaterial.uniforms["bloomRadius"].value = this.radius;
this.compositeMaterial.uniforms["bloomTintColors"].value =
this.bloomTintColors;
renderer.setRenderTarget(this.renderTargetsHorizontal[0]);
renderer.clear();
this.fsQuad.render(renderer);
// Blend it additively over the input texture
this.fsQuad.material = this.materialCopy;
this.copyUniforms["tDiffuse"].value =
this.renderTargetsHorizontal[0].texture;
if (maskActive) renderer.state.buffers.stencil.setTest(true);
if (this.renderToScreen) {
renderer.setRenderTarget(null);
this.fsQuad.render(renderer);
} else {
renderer.setRenderTarget(readBuffer);
this.fsQuad.render(renderer);
}
// Restore renderer settings
renderer.setClearColor(this._oldClearColor, this.oldClearAlpha);
renderer.autoClear = oldAutoClear;
}
getSeperableBlurMaterial(kernelRadius) {
return new ShaderMaterial({
defines: {
KERNEL_RADIUS: kernelRadius,
SIGMA: kernelRadius,
},
uniforms: {
colorTexture: { value: null },
texSize: { value: new Vector2(0.5, 0.5) },
direction: { value: new Vector2(0.5, 0.5) },
},
vertexShader: `varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}`,
fragmentShader: `#include <common>
varying vec2 vUv;
uniform sampler2D colorTexture;
uniform vec2 texSize;
uniform vec2 direction;
float gaussianPdf(in float x, in float sigma) {
return 0.39894 * exp( -0.5 * x * x/( sigma * sigma))/sigma;
}
void main() {\n\
vec2 invSize = 1.0 / texSize;\
float fSigma = float(SIGMA);\
float weightSum = gaussianPdf(0.0, fSigma);\
float alphaSum = 0.0;\
vec3 diffuseSum = texture2D( colorTexture, vUv).rgb * weightSum;\
for( int i = 1; i < KERNEL_RADIUS; i ++ ) {\
float x = float(i);\
float w = gaussianPdf(x, fSigma);\
vec2 uvOffset = direction * invSize * x;\
vec4 sample1 = texture2D( colorTexture, vUv + uvOffset);\
vec4 sample2 = texture2D( colorTexture, vUv - uvOffset);\
diffuseSum += (sample1.rgb + sample2.rgb) * w;\
alphaSum += (sample1.a + sample2.a) * w;\
weightSum += 2.0 * w;\
}\
gl_FragColor = vec4(diffuseSum/weightSum, alphaSum/weightSum);\n\
}`,
});
}
getCompositeMaterial(nMips) {
return new ShaderMaterial({
defines: {
NUM_MIPS: nMips,
},
uniforms: {
blurTexture1: { value: null },
blurTexture2: { value: null },
blurTexture3: { value: null },
blurTexture4: { value: null },
blurTexture5: { value: null },
dirtTexture: { value: null },
bloomStrength: { value: 1.0 },
bloomFactors: { value: null },
bloomTintColors: { value: null },
bloomRadius: { value: 0.0 },
},
vertexShader: `varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}`,
fragmentShader: `varying vec2 vUv;
uniform sampler2D blurTexture1;
uniform sampler2D blurTexture2;
uniform sampler2D blurTexture3;
uniform sampler2D blurTexture4;
uniform sampler2D blurTexture5;
uniform sampler2D dirtTexture;
uniform float bloomStrength;
uniform float bloomRadius;
uniform float bloomFactors[NUM_MIPS];
uniform vec3 bloomTintColors[NUM_MIPS];
float lerpBloomFactor(const in float factor) {
float mirrorFactor = 1.2 - factor;
return mix(factor, mirrorFactor, bloomRadius);
}
void main() {
gl_FragColor = bloomStrength * ( lerpBloomFactor(bloomFactors[0]) * vec4(bloomTintColors[0], 1.0) * texture2D(blurTexture1, vUv) +
lerpBloomFactor(bloomFactors[1]) * vec4(bloomTintColors[1], 1.0) * texture2D(blurTexture2, vUv) +
lerpBloomFactor(bloomFactors[2]) * vec4(bloomTintColors[2], 1.0) * texture2D(blurTexture3, vUv) +
lerpBloomFactor(bloomFactors[3]) * vec4(bloomTintColors[3], 1.0) * texture2D(blurTexture4, vUv) +
lerpBloomFactor(bloomFactors[4]) * vec4(bloomTintColors[4], 1.0) * texture2D(blurTexture5, vUv) );
}`,
});
}
}
UnrealBloomPassAlpha.BlurDirectionX = new Vector2(1.0, 0.0);
UnrealBloomPassAlpha.BlurDirectionY = new Vector2(0.0, 1.0);
export { UnrealBloomPassAlpha as UnrealBloomPass };
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