102 lines
2.5 KiB
GLSL
102 lines
2.5 KiB
GLSL
// Author: @samloeschen
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// Title: paint archipelago
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// Quick exploration in fractal brownian motion and generating
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// oil paint-like forms
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//generic random
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float random(in vec2 st)
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{
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return fract(sin(dot(st.xy, vec2(12.9898 ,78.233))) * 43758.5453123);
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}
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//@morgan3D noise
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float noise(in vec2 st)
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{
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vec2 i = floor(st);
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vec2 f = fract(st);
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// Four corners in 2D of a tile
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float a = random(i);
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float b = random(i + vec2(1.0, 0.0));
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float c = random(i + vec2(0.0, 1.0));
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float d = random(i + vec2(1.0, 1.0));
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vec2 u = f * f * (3.0 - 2.0 * f);
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return mix(a, b, u.x) +
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(c - a)* u.y * (1.0 - u.x) +
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(d - b) * u.x * u.y;
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}
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//could probably reduce octaves but meh
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#define octaves 11
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float fbm(in vec2 p)
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{
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float value = 0.0;
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float freq = 1.0;
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float amp = 0.5;
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for (int i = 0; i < octaves; i++) {
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value += amp * (noise((p - vec2(1.0)) * freq));
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freq *= 1.9;
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amp *= 0.6;
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}
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return value;
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}
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//basically all the fbm warps are offset by big slow sine patterns
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//when they diverge/are moving away from each other the fluidity feels faster,
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//and when they converge its more chilled out
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//I haven't tried animating the fbm scales yet but could be cool?
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//TODO: add params to further manipulate color ramps with the domain warping
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float pattern(in vec2 p)
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{
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vec2 offset = vec2(-0.5);
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//generate main peaks/valleys
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vec2 aPos = vec2(sin(iTime * 0.005), sin(iTime * 0.01)) * 6.;
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vec2 aScale = vec2(3.0);
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float a = fbm(p * aScale + aPos);
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//1st domain warp
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vec2 bPos = vec2(sin(iTime * 0.01), sin(iTime * 0.01)) * 1.;
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vec2 bScale = vec2(0.5);
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float b = fbm((p + a) * bScale + bPos);
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//2nd domain warp, yay now its paint. this one creates a bunch of diagonal countours that it wasn't
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//immediately obvious how to remove, but they kind of look like sun shafts so whatever
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vec2 cPos = vec2(-0.6, -0.5) + vec2(sin(-iTime * 0.001), sin(iTime * 0.01)) * 2.;
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vec2 cScale = vec2(2.); //this scale "zooms" the image
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float c = fbm((p + b) * cScale + cPos);
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return c;
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}
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//iq palette
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vec3 palette(in float t)
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{
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vec3 a = vec3(0.5, 0.5, 0.5);
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vec3 b = vec3(0.45, 0.25, 0.14);
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vec3 c = vec3(1.0 ,1.0, 1.0);
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vec3 d = vec3(0.0, 0.1, 0.2);
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return a + b * cos(6.28318 * (c * t + d));
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}
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#define hue(v) (.5 + cos(6.3 * (v) + vec4(0, 23, 21, 0)))
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void mainImage(out vec4 fragColor, in vec2 fragCoord)
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{
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vec2 p = fragCoord.xy / iResolution.xy;
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p.x *= iResolution.x / iResolution.y;
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float value = pow(pattern(p), 2.);
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vec3 color = hue(value + fbm(p + iTime * .1) + iTime * .5).rgb;
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fragColor = vec4(color, 1.0);
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}
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