> Just from your set up, I'd hazard a guess that you will run into
> numerical truncation problems related to the eplison value considering
> the largest and smallest values of scale (there is a better way to
> express this, but I can't think of it right now). Then again I could be
> wrong.

So far, I haven't.
I can set the planet diameter from 1' to 5000 miles, and the surface stays
exactly where it should relative to the scene origin, and components of the
objects are specified down to 0.001 inch with no problems so far.  When I
move the camera and zoom in on the details, they are still there.

> Could you be more specific as to what you are trying to do for top lit
clouds?

I'd like to set in some clouds, at a realistic altitude.
I'd like to have them as a sphere of some sort, around the planet, so that
they cast shadows on the ground, and that they don't look like cardboard
cutouts from underneath.

http://www.f-lohmueller.de/pov_tut/backgrnd/p_sky2.htm
This looks good to me, but I can't see how to translate it to my world.

Post a reply to this message