The previous post described a new system that allows rendering rich surfaces we call "meta-materials" using low-resolution geometry. Meta-materials cover ranges from 100 meters to 10 meters. What about anything more distant than that, that is, the range from tens of kilometers down to 100 meters?
It turns out the same system applies. You can think of this as "meta-meta-materials", we just do not call them that because one "meta" in a name is already too much. We have multiple objects that do fit that description. A terrain biome is one example.
In this post, you can see the results of applying this method to biome objects. All images are in faux solid color, which we use to make sure feature placement is correct.
Here is a single biome and the amount of geometry it takes to represent it:
In order to capture the detail, this biome also uses 1024x1024 texture maps for diffuse color, normals and other maps required for physically based rendering. Terrain voxels, which are generated on the fly, emit UV coordinate pairs which link the voxel's position in the world with the right section of these texture maps.
Here you can see multiple biomes in the same image, again in faux color, covering an area of approximately 3000 square kilometers:
Since most detail is contained by textures, it is possible to use a much coarser geometry. The following images show that we can crank up the mesh simplification and still obtain fairly good looking features:
As a creator of worlds, this feature is entirely transparent to you. These detail textures are automatically generated. Actually, all the content in these images was generated by our procedural algorithms, but if you had custom made maps, you would not need to be concerned about creating and maintaining the detail textures.
Like I said in the previous post, this is a technique frequently used in modern polygon-based terrain. The key here is this is now working on voxel terrains. These environments can be modified in real time by players. They can harvest materials, make trenches, even blow out entire craters in real time.