So I have a sphere textured with an animated map of Jupiter, and now I’m wanting to do a realistic atmosphere. I’ve gotten good results with a halo material on another sphere, but scaling both spheres up or down changes the relative thickness of the atmosphere. Would a volumetric material also work?
Ask pyro girl.
Check out what she made a day or two ago, it looks bada$$!
http://blenderartists.org/forum/showthread.php?t=193217
Keep in mind that “realistically,” you won’t see any real diffuse aspect to a gas giant’s atmosphere unless you’re so close you won’t see much of the patterns in the clouds and bands. Even on a much smaller terrestrial planet such as Earth, the edges don’t start to look “soft” until you’re close enough to orbit – see the NASA images from Apollo and the Voyager fly-bys for references.
That being said, consider using the Compositor for your atmospheric effect. A separate sphere acting as a “shell” on your planet, put on it’s own Render Layer and processed through a Blur node (and maybe other nodes for other effects), should provide a very controllable look no matter what your view of the planet, other than being so close the clouds themselves start to resolve into individual shapes.
You can use lots of Material tricks like Fresnel effects to keep the haze confined to the outer edges, add some variation in density with procedural textures, even animate changes in the look, lots of options.