Interest for this kind of thing has resurfaced again. You may remember the horrendous hack that was phantombeta implementing the psx fire as a camera texture displaying a grid of sectors changing color. Someone really needs to put an end to this madness and actually make this. I don't know if I could, though, it sounds like such a monumental task and I don't have enough time to work on anything like that. The way I'm thinking about it would involve moving all the 2d drawing code back to the DCanvas class, then make it so the Screen.* API works on instances of it rather than on the global screen framebuffer (which would be moved to the zscript globals, for backwards compatibility). Obviously ANIMDEFS would have to be expanded for creating these, just like it does for camera textures.
There really shouldn't be any concerns over performance when it comes to this, since we'd be using the renderer's own facilities for drawing, rather than working on raw pixels.