I am currently reading Game Engine Black Book: Wolfenstein 3D by Fabien Sanglard and I can very much recommend it. Following the author on Twitter (@fabynou), I found his interesting tweet on the Doom Fire Effect.

I wrote an article deconstructing the fire effect in DOOM on PSX: https://t.co/XDQ4TnP8mn. Thanks again @SVKaiser !!

— Fabien Sanglard (@fabynou) December 29, 2018

In his blog post he explains in much detail how this nice little effect was done and how it can be implemented.

This effect seemed like a good addition to that 32x32 RGB LED matrix I have sitting in my home office which is rendering different kinds of animations (I blogged about quite some time ago).

As usual, when creating a new animation for this frame, I prototyped it with Javascript for my other project dashydash, where it also makes for a cool transition effect. I had to tweak the sample slightly to make it suitable for the very limiting 32x32 "pixel" matrix, but this makes for the charm of these animations.

After that, it was easy to port the code to the actual Arduino sketch driving the RGB matrix.