Very tiny ray tracer which render images on CPU
- ppm format https://netpbm.sourceforge.net/doc/ppm.html
- ray tracing https://en.wikipedia.org/wiki/Ray_tracing_(graphics)
- line-sphere intersection https://en.wikipedia.org/wiki/Line%E2%80%93sphere_intersection
- Lambertian reflectance https://en.wikipedia.org/wiki/Lambertian_reflectance
- light inverse square law https://en.wikipedia.org/wiki/Inverse-square_law
- line-plane intersection https://en.wikipedia.org/wiki/Line%E2%80%93plane_intersection
- shadows http://www.it.hiof.no/~borres/j3d/explain/shadow/p-shadow.html