Hard Effects

6-way kaleidoscope of dots with a border

A picture built in steps: kaleidoscope, then draw dots, then color it, then finish with a border. Every step is listed below with its exact numbers.

The target picture for the shader challenge "6-way kaleidoscope of dots with a border"
Recreate this picture. You pass at a 99% match, then try to write it in fewer characters than the par.

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 528 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, 1.047) - 0.524); p = length(p) * float2(cos(a), sin(a)) (6 mirrored wedges)
Step 2: Pattern
g = p * 8.0; f = frac(g) - 0.5; m = 1.0 - smoothstep(0.29, 0.32, length(f))
Step 3: Colors
lerp(float3(0.85, 0.94, 0.94), float3(0.19, 0.34, 0.74), m)
Step 4: Finish
edge = min(min(uv.x, 1.0 - uv.x), min(uv.y, 1.0 - uv.y)); col = lerp(float3(0.32, 0.27, 0.88), col, smoothstep(0.055, 0.061, 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