This is how generic VT system works:
http://www.youtube.com/watch?v=p49vOX-_LyU
Here is some tech explanation:
http://silverspaceship.com/src/svt/
Anyway using for example 16k*16k textures is not main benefit (AFAIK John Carmack is using it for 128k*128k texture for terrain). It is more nice side effect .
What is going on. You take all textures you have and system makes one huge texture for whole game (for example 512k*512k, you can have even tiling textures there). Textures are streamed (so it solves texture streaming) and they have own oclussion system, so you stream only what is visible, it adjust quality of texture in realtime (!) and displays only visible pixels =>
- Constant texture memory budget. Even with 4k textures you have far lower memory usage than with for example 1k, because it loads only what you see.
- You dont have to care for high/low res version of textures, you just set size of cache and systems automatically adjusts quality (even very heavy scenes with hundreds of textures usually take around 120MB of video memory for textures, cca 5x less than with convencional technology)
- And main benefit, is that whole virtual texture can behave as ultimate texture atlas (whole game is one texture), it usually lowers dracalls 10x(!!!) in texture rich scenes. Imagine that performance boost.
- All this means, that it greatly improves/speeds up workflow, you dont have to do any atlases anymore and VT can handle even tiling texture, dont have to care about texture resolution, etc...
We licenced such system for Unity3D and now we are researching possibility of its migration to EE, because that system is very important for us. Maybe it can be interesting for Esenthel to cooperate directly with that company, because it would be benefecial for both sides (wider market for one side, great technology for EE).