Hard Effects
4×4 tiled polar grid
A picture built in steps: tile, then polar coordinates, then draw grid, then color it. 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 333 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: Tile
p = frac(p * 4.0 + 0.5) - 0.5 (repeat the picture 4 times across)- Step 2: Polar coordinates
p = float2(atan2(p.y, p.x) / 3.1415927, length(p) * 2.0) (x = angle from -1 to 1, y = distance)- Step 3: Pattern
e = abs(frac(p * 3.0) - 0.5); m = step(0.42, max(e.x, e.y)) (lines on the cell borders)- Step 4: Colors
lerp(float3(0.89, 0.44, 0.52), float3(0.48, 0.88, 0.39), m)
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