Hard Filters
Polar pixelated spiral with a dark vignette
A picture built in steps: polar coordinates, then pixelate, 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 449 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: Polar coordinates
p = float2(atan2(p.y, p.x) / 3.1415927, length(p) * 2.0) (x = angle from -1 to 1, y = distance)- Step 2: Pixelate
p = (floor(p * 24.0) + 0.5) / 24.0 (snap the position to a grid of 24 blocks per unit)- Step 3: Pattern
m = smoothstep(-0.2, 0.2, sin(5.0 * atan2(p.y, p.x) + 3.0 * length(p) * 6.28318))- Step 4: Colors
lerp(float3(0.18, 0.21, 0.69), float3(0.77, 0.31, 0.2), m)- Step 5: Finish
col *= 1.0 - 0.5 * smoothstep(0.4, 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