Accueil / npm / three@0.186.1 / examples / jsm / tsl / display / hashBlur.js
hashBlur.js
import { float, Fn, vec2, uv, sin, rand, TWO_PI, cos, Loop, vec4, premultiplyAlpha, unpremultiplyAlpha, convertToTexture, nodeObject } from 'three/tsl';
/**
* Applies a hash blur effect to the given texture node.
*
* The approach of this blur is different compared to Gaussian and box blur since
* it does not rely on a kernel to apply a convolution. Instead, it reads the base
* texture multiple times in a random pattern and then averages the samples. A
* typical artifact of this technique is a slightly noisy appearance of the blur which
* can be mitigated by increasing the number of iterations (see `repeats` parameter).
* Compared to Gaussian blur, hash blur requires just a single pass.
*
* Reference: {@link https://www.shadertoy.com/view/4lXXWn}.
*
* @tsl
* @function
* @param {Node<vec4>} textureNode - The texture node that should be blurred.
* @param {Node<float>} [bluramount=float(0.1)] - This node determines the amount of blur.
* @param {Object} [options={}] - Additional options for the hash blur effect.
* @param {Node<float>} [options.repeats=float(45)] - The number of iterations for the blur effect.
* @param {boolean} [options.premultipliedAlpha=false] - Whether to use premultiplied alpha for the blur effect.
* @return {Node<vec4>} The blurred texture node.
*/
export const hashBlur = /*#__PURE__*/ Fn( ( [ textureNode, bluramount = float( 0.1 ), options = {} ] ) => {
textureNode = convertToTexture( textureNode );
const repeats = nodeObject( options.repeats ) || float( 45 );
const premultipliedAlpha = options.premultipliedAlpha || false;
const tap = ( uv ) => {
const sample = textureNode.sample( uv );
return premultipliedAlpha ? premultiplyAlpha( sample ) : sample;
};
const targetUV = textureNode.uvNode || uv();
const blurred_image = vec4( 0. );
Loop( { start: 0., end: repeats, type: 'float' }, ( { i } ) => {
const angle = i.div( repeats ).mul( TWO_PI ).toConst();
const q = vec2( cos( angle ), sin( angle ) ).mul( rand( vec2( i, targetUV.x.add( targetUV.y ) ) ).add( bluramount ) );
const uv2 = vec2( targetUV.add( q.mul( bluramount ) ) );
blurred_image.addAssign( tap( uv2 ) );
} );
blurred_image.divAssign( repeats );
return premultipliedAlpha ? unpremultiplyAlpha( blurred_image ) : blurred_image;
} );