Unity3d Understand Voxel terrain

Question

I can't understand how create procedural world. I found article about voxel terrain generation, but it's only video or pictures and i found some terrain engine, but i can't understand it. I wanna tutorial step by step how to create simple voxel object. I want to create terrain, but not cube terrain.

Answer 1

There's two very different approaches to this.

Voxel terrain stores solid information - not just the surface of the terrain but the whole volume. The perfect example of this would be Minecraft, where the 'terrain' includes not just the surface but caves and tunnels as well. 3DCoat is a sculpting program that uses voxels, it's a good way to see what can and can't be done with them. The ability to represent any 3d volume is the big advantage of voxels.

Traditional surface terrain stores only the surface: there's nothing underneath. This surface could be an polygon mesh, but most often it's a regular guads (4-sided polygons) that are procedurally generated from a heightmap (which is a bitmap that stores heights instead of colors). Polygon terrains are basically just regular 3d models that happen to look like terrain; heightmap terrains can be easier to work with because they are easier to 'sculpt' quickly, and can be procedurally modified for things like explosion craters or erosion. A good example of a heightmap terrain program is the Unity terrain editor or a standalone tool like Vue

In general, voxels are much more expensive than heightmap or polygon terrain - a 1km by 1km terrain at 1 meter resolution includes 1 million bits of data; a 1 km by 1km voxel terrain that runs 1 km deep would be 1 billion samples (!) That can be cut down be smart enncoding (the hot trend here is sparse voxel octrees) but it's still a lot of data to manage. That's one of the reasons Minecraft has to be so blocky.

You could generate either voxels or heightmaps procedurally or by hand. Vterrain.org is a great resource for different techniques doing terrain.