Ray Casting 101 Makes Things Simple

Ray Casting 101 Makes Things Simple

[SSZCZEP] had a tough time understanding ray tracing to create 3d-like objects on a 2d map. So once he figured it out, he wrote a tutorial he hopes will be more accessible to those that try later.

If you’ve ever played Wolefeinstien 3D you will have seen the technique, although it crops up all over the place. The tutorial borrows an animated graphic from [Lucas Vieira] that really shows off how it works in a simplified way.

The explanation is pretty simple. From a point of view — that is a camera or the eyeball of a player, you draw rays out until they strike something. The distance and angle tell you how to render the scene. Instead of a camera, you can also figure out how a ray of light will fall from a light source.

There is a bit of math, but also some cool interactive demos to drive home the points. We wondered if Demos 3 and 4 reminded anyone else of an obscure vector graphics video game from the 1970s?

Most of the tutorial is pretty brute force, calculating points that you can know ahead of time won’t be useful. But if you stick with it, there are some concessions to optimization and pointers to more information.

Overall, a lot of good info and cool demos if this is your sort of thing. While it might not be the speediest, you can do ray tracing on our old friend the Arduino. Or, if you prefer, Excel.

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