Like the post, I wrote an old-school 3D engine that does the same math—renders flat-shaded polygons in an HTML5 Canvas.

Demo: https://engineersneedart.com/Phosphor3DTest/

(cursor keys drive the sand crawler, square-brackets change FOV)

Sources: https://github.com/EngineersNeedArt/Phosphor3D

(I was seeing a few anomalies and sent Claude to investigate—found a math error or two. There are still some anomalies in depth sorting the polygons but not due to the code, I believe—instead the model itself.)