Hard Effects
5-way kaleidoscope of spiral, four-way mirrored with a dark vignette
A picture built in steps: kaleidoscope, then mirror both ways, then draw spiral, then color it, then finish with a dark vignette. Every step is listed below with its exact numbers.
How this challenge works
You write a fragment shader that draws the picture above, live in your browser. A match bar shows how close you are, and the score combines accuracy, code size (the par is 491 characters in Unity (Built-in)) and GPU speed. Work in HLSL, GLSL, WGSL, Metal or Godot and export the result when you are done.
The numbers you need
- Space
p = (uv - 0.5) * float2(aspect, 1.0)- Step 1: Kaleidoscope
a = atan2(p.y, p.x); a = abs(fmod(a + 6.2831853, 1.257) - 0.628); p = length(p) * float2(cos(a), sin(a)) (5 mirrored wedges)- Step 2: Mirror both ways
p = abs(p)- Step 3: Pattern
m = smoothstep(-0.2, 0.2, sin(3.0 * atan2(p.y, p.x) + 4.0 * length(p) * 6.28318))- Step 4: Colors
lerp(float3(0.13, 0.89, 0.42), float3(0.34, 0.09, 0.73), m)- Step 5: Finish
col *= 1.0 - 0.55 * smoothstep(0.3, 0.8, length(s)), s = (uv - 0.5) * float2(aspect, 1.0)
Solve it in your language
Unity (Built-in), Unity (URP), Unreal, Shadertoy / WebGL, OpenGL (LWJGL, raylib), three.js, GameMaker, LÖVE (Lua), Godot, Apple (iOS, macOS), WebGPU / Bevy.
Start coding