Medium FiltersAnimated
CRT monitor
Old TV: curved screen, scanlines, a flickering brightness and dark corners.
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 952 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
- Curve
c = uv * 2.0 - 1.0; c *= 1.0 + 0.1 * dot(c, c) * ... → q = c * 0.5 + 0.5 (use: c = c * (1.0 + 0.12 * dot(c.yx, c.yx)))- Outside
black if q is outside 0..1- Scanlines
0.85 + 0.15 * sin(q.y * 600.0)- Flicker
0.97 + 0.03 * sin(time * 40.0)- Vignette
1.0 - 0.6 * dot(c, c) * 0.5
Helper functions provided
The toolbox has: scene(). Add them above your frag function with one click.
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