What is a voxel?

  • So i know Minecraft is a voxel based game. To my knowledge, a voxel is an object whose position is stored as relative to another voxel. In minecraft the voxels happen to be rendered as cubes.
    So is Rising World also voxel? Does splitting the word into smaller chunks, each chunk relative to another make it a voxel game?


    I ask this because I see people label any game with blocks as a voxel game. I read up on voxels and apparently Crysis was a voxel game.


    The landscape is a gigantic mesh but is the mesh drawn as an interpretation of voxel data?

  • It depends on the context. When talking about rendering (or "voxel graphics"), there are barely any games out there which are really voxel based. Most games (including Minecraft, Crysis, but also Rising World) use polygons to render the game world. Having a voxel based rendering is a completely different approach, for example Comanche or Outcast used voxels for rendering.
    But the term "voxel" can also describe a datapoint in a three-dimensional grid (as you suspected), for example containing terrain information. Most games use heightmaps to describe the terrains (basically like a two-dimensional array which contains the actual height value for a given X-Z-coordinate), unfortunately heightmaps are quite limited (although sufficient for most games), since it's not possible to have overhangs or caves this way. When the terrain is stored in a three-dimensional data grid, you have full freedom to describe various terrain features precisely. Minecraft or Rising World use a three-dimensional datagrid for the terrain, Crysis uses a mixture or heightmaps and three-dimensional grids. That labels those games as "voxel based" (referring to the fact that the world information are stored in a three-dimensional data grid).
    Another advantage of a three-dimensional data grid is that this is basically the only way to have a truely modifiable terrain. It's nearly impossible to store those information in a heightmap (unless you just want to have something like craters on the terrain surface). On the other hand, a big disadvantage of a three-dimensional data grid is the *much* higher memory consumption (it's basically like multiple layers of heightmaps: if you have a total terrain height of 256 units [or "blocks"], the memory consumption is 256 times higher compared to a simple heightmap).

  • Ok, this makes a lot of sense so basically the terrain and subterrains are rendered still in polygons but essentially molded into a shape represented by the data points. So whenever we mine out a hole in Rising World are we essentially removing a data point (or adding maybe) voxel data point causing the rendering engine to redraw (in polygons) that area of the mountain to account for the change?


    I guess true Voxel rendering would be a departure from using polygons and textures to render a spot. My understanding is that it essentially creates lots of tiny blobs to make up a larger structure. But to create the individual blob, arent we still using mesh and thus just making the mesh more complicated? I found a video somewhere which showed how instead of applying a cobblestone texture to a block to make a wall that instead each rock in the wall was rendered. Isn't this still increasing polygon count? Doesnt everything ultimately have to be converted into a mash shape which then in turn gets converted to a bitmap image to display on your screen?


    Could you recommend some reading material or videos? I'd really love to understand the voxel rendering better. The datapoints are easy to comprehend.

Participate now!

Don’t have an account yet? Create a new account now and be part of our community!