wrote:
I'm working on a project of modeling the stars of the
constellations in
3-D; not for their positions relative to Earth, but relative to any
given person being at 0,0,0.

Is there a simple formula for this? ...or better yet, do you know
anyone who has them on the net or in a book?

Ioannis responded:

It's going to be very messy. ...
Since the celestial dome appears "spherical", be prepared to be
bombarded with thousands of sin's and cos's.

Yikes! You make this sound like a major undertaking; it's actually
a problem in elementary trigonometry that any kid in a high-school
pre-calculus class should be able to solve in 5 minutes.

Conversion from RA/Dec to rectangular coordinates requires two sines
and two cosines -- or two and three, depending how you count.

My only question is about the meaning of the phrase "relative not to
Earth but to a person at 0,0,0". I've been searching for 0,0,0 all
my life, and I still haven't found it!

- Tony Flanders