USE TURBOWARP. The project is EXTREMELY slow and slightly broken on regular Scratch. I've done it. I've finally made a full path-traced rendering engine on Scratch, complete with a shape editor. This has been a goal of mine for months now, and now I can move on to other things.
All made by me, but most equations and algorithms for things like ray bouncing had to be found online. It's not perfect, but I really made this just to prove that I could, and I'm extremely proud of it.