I guess I am easily distracted by geeky stuff. Yesterday I needed a fake / fantasy planet for a piece of art I am working on. So I thought I would just go find something open-source-ish someone else has done. That would have been the obvious 60-second solution.
But then I saw this site, which apparently is one for enthusiasts of - you guessed it - making planet and space art. So I thought I would play around with it. About 6 hours on the computer later, I have a planet and a lot of tools to make more, and actually had a surprising amount of fun doing it. First, the planet, click to enlarge:
The image you get when you click on it is only about a quarter of the full resolution of 5000x5000 of the original.
This is all done in Photoshop, faking the 3D and lighting effects, though there are tutorials and that same site discussing how to do this even better using 3D rendering. To make this, I started with a planet map using this tutorial. The land image I used as a texture seed is here. The final map looks like this (again I had to cut the resolution by 75% from the original 8000x4000).
The above was a bit dark so I ended up stacking two on top of each other with the top set to blend mode "screen" and this really made it pop. The cloud map I used a portion of is apparently a favorite among planet illustrators -- you can find it here. Again, here it is but reduced in size:
From these last two we select a large circle (of the same size from each) and spherize them in Photoshop.
Here it is before the atmosphere and shadow effects, which are layered on and can be adjusted after the fact
Then, follow the second half of this tutorial when he talks about atmosphere and shadows to get the final result.
And the shadow can go the other way as well:
If anyone is really interested, I can send you the photoshop file with all the layers so you can see how it works. Update: The files are huge, about 500MB each, in part because I leave copies of all the resources I use in hidden layers. But here they are, one for the flat map and one for the planet: http://climatemovie.s3.amazonaws.com/planet test.psd and here: http://climatemovie.s3.amazonaws.com/continents.psd