Yeah I figured others were working on this - in fact I've seen some of the results others have had, but some mentioned problems. So I figured I'd see if I could resolve some of those issues and provide the scene files for others to play with.
The clouds are an image mask downloaded from the 'net. I can't quite get TG2's clouds to achieve that effect, though I've created some decent planetary-scale clouds before with large scales and high warp values.
The images I'm working with vary in size, but the main planet texture is "only" 5400x2700 at this point and you can see it's a little soft in the render I posted (more so at the original 1600x1200 size). I'll be working with the "Blue Marble Next Generation" data to make something higher resolution and see just how big I can make it before TG2 chokes. I'm also experimenting to see whether different image formats - tiff and jpg for example - allow for different resolution images to be loaded. Theoretically they should be roughly the same because jpg will be uncompressed for use in rendering, but theory often proves incorrect.
Making this work from space down to the ground would be really, really hard, at least for real Earth topography. You'd need to use all the available DEM data for the entire Earth - something like 5 terabytes worth.
I could work on doing it with procedurals, but the results probably wouldn't be all that great. So for now it's focused on just being a from-space scene, as close as low Earth orbit I'd say (still in space but close to the atmosphere).
- Oshyan