Lesson 1 of 10 · Noise in GLSL
Static
Raw noise. Pure hash.
In Forces you used fb() as a black box, it generated irregular texture and you moved it. Now we are going to open it up. Everything starts here: raw noise. Think of the static on an old TV, visual noise filling the screen.
h2() generates that. Give it a coordinate, it returns a number between 0 and 1 that looks random. Controlled chaos.
h2() generates chaos. Every cell, a digital die.
h2(p)A hash. 2D position goes in, pseudo-random value comes out. The foundation of everything that comes next, and of the
fb() you already know.Change
12. to 50., finer, digital grit. To 3., big blocks like bathroom tile.The code
void main(){
vec2 p = (2.*gl_FragCoord.xy - R) / min(R.x, R.y);
vec2 grid = floor(p * 12.0);
float id = h2(grid);
float dead = step(0.92, id);
float scan = step(0.5, sin(gl_FragCoord.y * 1.5) * 0.5 + 0.5) * 0.12;
vec3 col = vec3(0.0);
col.r = step(0.6, h2(grid + 0.1)) * 0.8;
col.g = step(0.5, h2(grid + 0.2)) * 0.9;
col.b = step(0.55, h2(grid + 0.3)) * 0.7;
col *= 1.0 - dead;
col += vec3(0.9, 0.0, 0.4) * dead * 0.3;
col *= 1.0 - scan;
col += vec3(0.01, 0.02, 0.02);
col = hueShift(col, 0.0);
gl_FragColor = vec4(col, 1.);
}