I wrote the code for this in late 1993 https://www.youtube.com/watch?v=9KoUyFhddIs&t=102 https://www.youtube.com/watch?v=9KoUyFhddIs&t=102 . You can find the C

I wrote the code for this in late 1993 https://www.youtube.com/watch?v=9KoUyFhddIs&t=102 https://www.youtube.com/watch?v=9KoUyFhddIs&t=102 . You can find the C + assembly source code in https://archive.scene.org/mirrors/hornet/code/effects/land/ign_land.zip https://archive.scene.org/mirrors/hornet/code/effects/land/i... Yep, we used a lookup table with built-in levels of detail. Since rays always sample the terrain at the same Z distances from the camera, the lookup was trivial. Rendering vertical lines had additional benefits back then, including faster use of paged VGA video modes and, as described, doing circular projection to avoid deformations on the sides of the screen.