My understanding is that Orbx uses a combination of hand annotated 3D (often custom) objects on photo textures, with seasonal colour variations for the high detail areas and hand annotated autogen on landclass tiles for the other areas to produce that amazing result. Hopefully with the next iteration of X-Plane the ability to either match or exceed the FsX tech will be there. As always, it the ability for the sim to deliver the highest suspension of disbelief that is the key for a great experience. Cheers and thanks for sharing