Let us go back to the year 1992. The CPUs were 1000 times slower than today and the acceleration via a GPU was unknown or unaffordable. 3D games were calculated exclusively on the CPU and the rendering engine rendered filled polygons with a single color.
Game Gunship 2000 published by MicroProse in 1991
It was during that year NovaLogic published the game Comanche .
Game Comanche published by NovaLogic in 1992
The graphics were breathtaking for the time being and in my opinion 3 years ahead of its time. You see many more details such as textures on mountains and valleys, and for the first time a neat shading and even shadows. Sure, it’s pixelated, but all games in those years were pixelated.
Comanche uses a technique called Voxel Space , which is based on the same ideas like ray casting . Hence the Voxel Space engine is a 2.5D engine, it doesn’t have all the levels of freedom that a regular 3D engine offers.