Created
March 31, 2021 08:27
-
-
Save hb3p8/eaf56da1526db60dd3b9d4e406de2917 to your computer and use it in GitHub Desktop.
Generate normals for car paint base layer
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<!DOCTYPE html> | |
<html> | |
<head> | |
<meta content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0" name="viewport" /> | |
<meta charset=utf-8> | |
</head> | |
<body> | |
<canvas width=2048 height=2048 style="width: 800px; height: 800px"></canvas> | |
</body> | |
<script language="javascript" src="https://npmcdn.com/regl/dist/regl.js"></script> | |
<script language="javascript"> | |
var regl = createREGL({canvas: document.getElementsByTagName('canvas')[0]}) | |
const setupQuad = regl({ | |
frag: ` | |
precision highp float; | |
varying vec2 uv; | |
const float Scale = 200.0; | |
vec2 hash( vec2 p ) | |
{ | |
p = mod(p, Scale); // tile | |
p = vec2(dot(p,vec2(127.1,311.7)), | |
dot(p,vec2(269.5,183.3))); | |
return fract(sin(p)*18.5453); | |
} | |
// return distance, and cell id | |
vec2 voronoi( in vec2 x ) | |
{ | |
vec2 n = floor( x ); | |
vec2 f = fract( x ); | |
vec3 m = vec3( 8.0 ); | |
for( int j=-1; j<=1; j++ ) | |
for( int i=-1; i<=1; i++ ) | |
{ | |
vec2 g = vec2( float(i), float(j) ); | |
vec2 o = hash( n + g ); | |
vec2 r = g - f + o; | |
float d = dot( r, r ); | |
if( d<m.x ) | |
m = vec3( d, o ); | |
} | |
return vec2( sqrt(m.x), m.y+m.z ); | |
} | |
const float PHI = 1.61803398874989484820459; | |
float gold_noise(in vec2 xy, in float seed) | |
{ | |
return fract(tan(distance(xy*PHI, xy)*seed)*xy.x); | |
} | |
vec3 gold_noise3(in vec2 xy, in float seed) | |
{ | |
return vec3 (gold_noise(xy, seed+1.0), | |
gold_noise(xy, seed+2.0), | |
gold_noise(xy, seed+3.0)); | |
} | |
// ----------------------------------------------- | |
void main() { | |
vec2 p = uv; | |
// compute voronoi patterm | |
vec2 c = voronoi( p * Scale ); | |
// colorize | |
//vec3 col = 0.5 + 0.5*cos( c.y*6.2831 + vec3(0.0,1.0,2.0) ); | |
vec3 rnd_normal = gold_noise3(vec2(c.y, c.y), 42.0) * 2.0 - 1.0; | |
vec3 normal = normalize (mix (vec3 (0.0, 0.0, 1.0), rnd_normal, 0.2)); | |
normal.xy = normal.xy * 0.5 + 0.5; | |
gl_FragColor = vec4( normal, 1.0 ); | |
} | |
`, | |
vert: ` | |
precision highp float; | |
attribute vec2 position; | |
varying vec2 uv; | |
void main() { | |
uv = 0.5 * (position + 1.0); | |
gl_Position = vec4(position, 0, 1); | |
}`, | |
attributes: { | |
position: [ -4, -4, 4, -4, 0, 4 ] | |
}, | |
depth: { enable: false }, | |
count: 3 | |
}) | |
regl.frame(function () { | |
setupQuad(() => { | |
regl.draw() | |
}) | |
}) | |
</script> | |
</html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Open html in a browser and save the image from canvas with via right click menu