ShaderBattle

Easy Game effectsAnimated

Iris-out scene transition

The classic cartoon "iris out": a circle shrinks around a point of interest and everything outside it goes black.

Play this challenge All challenges
The target picture for the shader challenge "Iris-out scene transition"
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 813 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)
Focus point
c = float2(0.2, -0.1)
Radius
0.8 * (1.0 - frac(time * 0.3))
Mask
1.0 - smoothstep(radius - 0.004, radius, length(p - c))
Result
scene(uv) * mask

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

More game effects challenges