There's not much info in the video there. But if you search star citizen virtual terrain texturing there are some interesting links, like https://www.adobe.com/products/substance3d/magazine/star-citizen-texturing-sci-fi-open-world-game-substance.html
it looks like they send the terrain to the GPU as a texture and generate the mesh there instead of making a mesh and sending that to the GPU. This isn't exactly revolutionary - in fact, it's generally what you should be doing. you don't have to store lods, you can take advantage of your texture streaming system, you can…