It depends: Are the stars objects which move within the field of vision? Or are they stationary objects which "sit" in the background? I think most starfields onscreen are 2D, with some 3D elements added for depth. (Cost-wise, it's cheaper to do, too.)
Timothy Fox has a great site which explains a few aspects of starfield animation creation. See
https://www.geocities.com/special_eff...starfield.html
Btw, I understand that ILM, Sony Pictures Imageworks, Digital Domain and other CG shops tend to write custom C language programs for starfields which surpass off-the-shelf software solutions. Why? So their work is distinctive and unique (and because they
can )
(I'd comment on Farscape and Space: Above And Beyond starfields if I had references handy. I don't.)
Michael
:colwar: