Drag the red square in the center of the light anywhere (but inside any object) and wait for it to render (note: it will lag for a second because 360 rays have to render in one frame.) Once it renders you have your finished picture! You can change the objects by changing the costume of "Sprite2."
Exactly like in real life on how light works! New update (7/15/2025 1.2 Update): You can now move in real time using the arrow keys! Recommended in Turbowarp: https://turbowarp.org/1163804688?turbo&fps=60&hqpen