I think the contrast between the two sides is typically greater with an optically thick disk, and it looks like you are rendering an optically thin disk. I think that's the main difference from what I was expecting when I saw it.
Very cool demo! Thanks for sharing!
(For reference, my experience rendering black holes is recreating Luminet's rendering from the late 70s: https://www.ioccc.org/2025/cesmoak/index.html )
True, the disk is rendered optically (and geometrically) thin. This is done so that real-time performance is attained on devices like phones – volumetric GR rendering would be significantly more expensive. The jet (zoom out to see it) is rendered with full volumetric effects, because it's just special relativity there.
Fortran punchcard style to render black holes?! That's really going full circle to the origins, I really enjoyed reading about Luminet's work some time ago.