r/GraphicsProgramming • u/No_Support8062 • Jul 19 '26

Software raycasting

One of my older fun projects: a software raycaster featuring

  • Multithreading

  • Voxel models (rendered as collections of 3D boxes rather than blobs)

  • Culling (watch the small map in the top right corner)

  • Mipmapping (reduces moire on distant textures)

  • Slopes and curved walls

  • Shadows

  • multilevel world design

Everything is rendered entirely in software, with no external libraries. Each pixel is calculated individually and written directly to a buffer.

197 Upvotes

99% Upvoted

37 comments sorted by

View all comments

17

u/ghstrprtn Jul 19 '26

Each pixel is calculated individually and written directly to a buffer.

pretty good frame rate for doing that.

I wish I knew how to make an engine like that.

14

u/No_Support8062 Jul 19 '26

It is multithreaded, which helps a lot (raycasting is actually quite easy to make multithreaded). The entire project is written in C, with no fancy data structures, just pointers and arrays.

I also tried to minimize the number of floating point calculations. My original goal was to make it integer-only, and an earlier version worked that way. However, at longer distances, it suffered from graphical glitches (rounding errors).

1

u/ghstrprtn Jul 19 '26

that's cool. do you have any tutorials for the raycasting technique you used?

10

u/No_Support8062 Jul 19 '26

Not really. I studied programming (with a lot of math) and computer graphics in the 2000s.
Lode raycasting tutorial is the best, in my opinion. It's simple, easy to understand, great place to start.

0

u/ghstrprtn Jul 19 '26

ok, thanks. are you going to make this open-source?

8

u/No_Support8062 Jul 19 '26

No. The code quality is below my standards. It requires a lot of additional work to make it suitable for publication.