Real-Time Ray Tracing On An SNES? There's A Mod Chip For That
When people think ray tracing, typically they think of some pie in the sky idea with an incredibly powerful GPU inside an incredibly powerful computer. That does not have to be the case, however. Ben Carter, a freelance game developer and software engineer from Japan, made a device for the Super Nintendo (Famicom in Japan) to do ray tracing
in what he calls the SuperRT expansion.
Carter, who is part of Shironeko Labs
, had a goal in mind when he started this project: “learn Verilog and FPGA design.” This idea eventually grew into building an expansion for the SNES
to do raytracing. From there, he “wanted to try and do was something akin to the Super FX chip used in titles such as Star Fox, where the SNES runs the game logic and hands off a scene description to a chip in the cartridge to generate the visuals.” You can take a look at what Carter accomplished over the past year in the video below.
As he explains in the video above, he wants to keep the spirit of 90s technology, so he has restricted himself to using just a single custom chip for the design. This is also why the ray tracing happens at an output resolution of a whopping 200x160p. There is a lot of math going on, and that resolution exactly fills the VRAM in two chunks. The only problem with that is the VRAM is filled over two frames, so the effective maximum framerate is 30FPS. But in reality, the whole thing runs at 20FPS “primarily due to some bottlenecks with the logic on the SNES side at present.”
Even though the SNES runs in low-resolution and at low-FPS, it is doing so with real time ray tracing, which is nuts. The entire video describing the project is worth watching, just so you understand what went into it all.