three
Version:
JavaScript 3D library
274 lines (192 loc) • 6.32 kB
JavaScript
import {
AdditiveBlending,
HalfFloatType,
ShaderMaterial,
UniformsUtils,
Vector2,
WebGLRenderTarget
} from 'three';
import { Pass, FullScreenQuad } from './Pass.js';
import { ConvolutionShader } from '../shaders/ConvolutionShader.js';
/**
* A pass for a basic Bloom effect.
*
* {@link UnrealBloomPass} produces a more advanced Bloom but is also
* more expensive.
*
* ```js
* const effectBloom = new BloomPass( 0.75 );
* composer.addPass( effectBloom );
* ```
*
* @augments Pass
*/
class BloomPass extends Pass {
/**
* Constructs a new Bloom pass.
*
* @param {number} [strength=1] - The Bloom strength.
* @param {number} [kernelSize=25] - The kernel size.
* @param {number} [sigma=4] - The sigma.
*/
constructor( strength = 1, kernelSize = 25, sigma = 4 ) {
super();
// combine material
/**
* The combine pass uniforms.
*
* @type {Object}
*/
this.combineUniforms = UniformsUtils.clone( CombineShader.uniforms );
this.combineUniforms[ 'strength' ].value = strength;
/**
* The combine pass material.
*
* @type {ShaderMaterial}
*/
this.materialCombine = new ShaderMaterial( {
name: CombineShader.name,
uniforms: this.combineUniforms,
vertexShader: CombineShader.vertexShader,
fragmentShader: CombineShader.fragmentShader,
blending: AdditiveBlending,
transparent: true
} );
// convolution material
const convolutionShader = ConvolutionShader;
/**
* The convolution pass uniforms.
*
* @type {Object}
*/
this.convolutionUniforms = UniformsUtils.clone( convolutionShader.uniforms );
this.convolutionUniforms[ 'uImageIncrement' ].value = BloomPass.blurX;
this.convolutionUniforms[ 'cKernel' ].value = buildKernel( sigma );
/**
* The convolution pass material.
*
* @type {ShaderMaterial}
*/
this.materialConvolution = new ShaderMaterial( {
name: convolutionShader.name,
uniforms: this.convolutionUniforms,
vertexShader: convolutionShader.vertexShader,
fragmentShader: convolutionShader.fragmentShader,
defines: {
'KERNEL_SIZE_FLOAT': kernelSize.toFixed( 1 ),
'KERNEL_SIZE_INT': kernelSize.toFixed( 0 )
}
} );
/**
* Overwritten to disable the swap.
*
* @type {boolean}
* @default false
*/
this.needsSwap = false;
// internals
this._renderTargetX = new WebGLRenderTarget( 1, 1, { type: HalfFloatType } ); // will be resized later
this._renderTargetX.texture.name = 'BloomPass.x';
this._renderTargetY = new WebGLRenderTarget( 1, 1, { type: HalfFloatType } ); // will be resized later
this._renderTargetY.texture.name = 'BloomPass.y';
this._fsQuad = new FullScreenQuad( null );
}
/**
* Performs the Bloom pass.
*
* @param {WebGLRenderer} renderer - The renderer.
* @param {WebGLRenderTarget} writeBuffer - The write buffer. This buffer is intended as the rendering
* destination for the pass.
* @param {WebGLRenderTarget} readBuffer - The read buffer. The pass can access the result from the
* previous pass from this buffer.
* @param {number} deltaTime - The delta time in seconds.
* @param {boolean} maskActive - Whether masking is active or not.
*/
render( renderer, writeBuffer, readBuffer, deltaTime, maskActive ) {
if ( maskActive ) renderer.state.buffers.stencil.setTest( false );
// Render quad with blurred scene into texture (convolution pass 1)
this._fsQuad.material = this.materialConvolution;
this.convolutionUniforms[ 'tDiffuse' ].value = readBuffer.texture;
this.convolutionUniforms[ 'uImageIncrement' ].value = BloomPass.blurX;
renderer.setRenderTarget( this._renderTargetX );
renderer.clear();
this._fsQuad.render( renderer );
// Render quad with blurred scene into texture (convolution pass 2)
this.convolutionUniforms[ 'tDiffuse' ].value = this._renderTargetX.texture;
this.convolutionUniforms[ 'uImageIncrement' ].value = BloomPass.blurY;
renderer.setRenderTarget( this._renderTargetY );
renderer.clear();
this._fsQuad.render( renderer );
// Render original scene with superimposed blur to texture
this._fsQuad.material = this.materialCombine;
this.combineUniforms[ 'tDiffuse' ].value = this._renderTargetY.texture;
if ( maskActive ) renderer.state.buffers.stencil.setTest( true );
renderer.setRenderTarget( readBuffer );
if ( this.clear ) renderer.clear();
this._fsQuad.render( renderer );
}
/**
* Sets the size of the pass.
*
* @param {number} width - The width to set.
* @param {number} height - The width to set.
*/
setSize( width, height ) {
this._renderTargetX.setSize( width, height );
this._renderTargetY.setSize( width, height );
}
/**
* Frees the GPU-related resources allocated by this instance. Call this
* method whenever the pass is no longer used in your app.
*/
dispose() {
this._renderTargetX.dispose();
this._renderTargetY.dispose();
this.materialCombine.dispose();
this.materialConvolution.dispose();
this._fsQuad.dispose();
}
}
const CombineShader = {
name: 'CombineShader',
uniforms: {
'tDiffuse': { value: null },
'strength': { value: 1.0 }
},
vertexShader: /* glsl */`
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}`,
fragmentShader: /* glsl */`
uniform float strength;
uniform sampler2D tDiffuse;
varying vec2 vUv;
void main() {
vec4 texel = texture2D( tDiffuse, vUv );
gl_FragColor = strength * texel;
}`
};
BloomPass.blurX = new Vector2( 0.001953125, 0.0 );
BloomPass.blurY = new Vector2( 0.0, 0.001953125 );
function gauss( x, sigma ) {
return Math.exp( - ( x * x ) / ( 2.0 * sigma * sigma ) );
}
function buildKernel( sigma ) {
// We loop off the sqrt(2 * pi) * sigma term, since we're going to normalize anyway.
const kMaxKernelSize = 25;
let kernelSize = 2 * Math.ceil( sigma * 3.0 ) + 1;
if ( kernelSize > kMaxKernelSize ) kernelSize = kMaxKernelSize;
const halfWidth = ( kernelSize - 1 ) * 0.5;
const values = new Array( kernelSize );
let sum = 0.0;
for ( let i = 0; i < kernelSize; ++ i ) {
values[ i ] = gauss( i - halfWidth, sigma );
sum += values[ i ];
}
// normalize the kernel
for ( let i = 0; i < kernelSize; ++ i ) values[ i ] /= sum;
return values;
}
export { BloomPass };