three
Version:
JavaScript 3D library
62 lines (35 loc) • 938 B
JavaScript
/**
* Afterimage shader
* I created this effect inspired by a demo on codepen:
* https://codepen.io/brunoimbrizi/pen/MoRJaN?page=1&
*/
var AfterimageShader = {
uniforms: {
"damp": { value: 0.96 },
"tOld": { value: null },
"tNew": { value: null }
},
vertexShader: [
"varying vec2 vUv;",
"void main() {",
" vUv = uv;",
" gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
"}"
].join( "\n" ),
fragmentShader: [
"uniform float damp;",
"uniform sampler2D tOld;",
"uniform sampler2D tNew;",
"varying vec2 vUv;",
"vec4 when_gt( vec4 x, float y ) {",
" return max( sign( x - y ), 0.0 );",
"}",
"void main() {",
" vec4 texelOld = texture2D( tOld, vUv );",
" vec4 texelNew = texture2D( tNew, vUv );",
" texelOld *= damp * when_gt( texelOld, 0.1 );",
" gl_FragColor = max(texelNew, texelOld);",
"}"
].join( "\n" )
};
export { AfterimageShader };