Brandan Whearty <ema### [at] domaincom> wrote:
> I just finished rendering this little file as a Quicktime Movie, [Start
> - 1, End - 50, Frames - 50] and everything worked ok except for the
> skysphere, which jumps around like TV static.  Is there an easy way to
> minimize this effect?

The problem is with the starfield texture.  Using a granite pattern scaled
that small means that you don't actually see the coherent pattern itself.
Instead, each ray fired at the sky-sphere picks up points in the pattern so
far apart (relative to the size of the pattern's details) that they might as
well be random noise.  This, of course, is perfect for still starfield
scenes.  In animations with a moving camera, however, each camera viewpoint
results in a different set of 'random' points, making the starfield flicker
from frame to frame.

The solution is to use a pigment (such as crackle, or a pre-rendered
image-map) that looks like a starfield at a larger scale, so the samples
aren't taken randomly, e.g.:

sky_sphere {
   pigment {crackle color_map {[.5 rgb 0] [1 rgb 2]} scale .01}
   }

Or, you can create the stars using objects - my Galaxy Include file includes
various functions for this and other space backgrounds:

   http://www.geocities.com/ccolefax

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