Lets assume I wish to render a large, 3D, star object in a game engine using OpenGL. I can use a few different meshing methods: this includes mapping a cube to a sphere (with better subdivision to reduce distortion), a primitive lattitudional/longitudional based "globe" mesh, or a selectively subdivided icosphere. I would choose whatever would be easiest to apply the 3D effect to: I'm guessing an isocahedron, since it doesn't distort as much and the issues with mathematical discontinuities (when finding the Tangential, Normal, and Binormal) vectors should not be a worry (unless rendering the following effect would use a bump/normal mapping technique with a GPU-generated texture?)
Further, lets assume I wish to render a boiling, roiling, or vaguely evolving surface. The diamond-square algorithm could generate the proper effect, but how could this be used in 3D to generate something that looks vaguely like the surface of a star? Could I use the GPU to generate a texture that is then evolved with time, and use a procedural noise algorithm that includes the analytical derivatives to do so(for acquiring normal/bump map components to add "depth")? Should the noise algorithm be in 2D or 3D?
Lastly, what if I want to render the corona of the star in some volumetric fashion as well? Corona's created with billboards work well enough, but rapidly fall apart in appearance once the viewpoint gets closer to the star (as is common with sprite-based techniques).