I love non-standard computer rendering methods.
Most games use rasterisation which takes a number of triangles (polygons) and calculates where on the screen it should be.
An alternative that's becoming more common is ray tracing which starts with the screen coordinates and and calculates what's in that direction.
Rasterisation is a really clever trick to do more with less powerful computers, and was the only way to do any kind of realtime graphics in the early days of computers.
Ray Tracing takes much more computing power, but allows for interesting things like non-euclidian geometry, 360 degree field of view, and picture-in-picture with no loss of performance (compared to ray tracing without these additions).