Hard Effects
12-way kaleidoscope of stripes, mirrored with a border
A picture built in steps: kaleidoscope, then mirror left/right, then draw stripes, then color it, then finish with a border. 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 505 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, 0.524) - 0.262); p = length(p) * float2(cos(a), sin(a)) (12 mirrored wedges)- Step 2: Mirror left/right
p.x = abs(p.x)- Step 3: Pattern
m = step(0.5, frac(dot(p, float2(1.0, -1.0)) * 6.0))- Step 4: Colors
lerp(float3(0.94, 0.45, 0.4), float3(0.34, 0.94, 0.43), m)- Step 5: Finish
edge = min(min(uv.x, 1.0 - uv.x), min(uv.y, 1.0 - uv.y)); col = lerp(float3(0.99, 0.87, 0.54), col, smoothstep(0.04, 0.046, edge))
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