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Easy 2D

Traffic light

A dark box with three round lights: red, yellow and green.

Play this challenge All challenges

The target picture for the shader challenge "Traffic light" — 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

Background: float3(0.12, 0.12, 0.15)
Box: half-size (0.14, 0.42), color float3(0.2, 0.2, 0.22)
Lights: radius 0.1 (edge from 0.09), at y = +0.28, 0.0, -0.28
Colors: red (0.95,0.2,0.15), yellow (0.98,0.8,0.1), green (0.2,0.85,0.35)

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.