Re: your mail
John Rohlf (jrohlf++at++tubes)
Thu, 29 Sep 94 13:26:25 PDT
>
> Hey all,
> In my Performer application, I'm rendering some stars in a space environment as point light sources.
> I use actual celestial coordinates converted to Earth-centered rectangular
> coordinates, so my stars end up as a "celestial sphere" surrounding the
> Earth. This was working well until I discovered that if I move far
> enough in my world, objects that aren't within my "celestial sphere" (such
> as the Sun or a distant planet, etc) will appear "behind" the stars. For
> various reasons, I don't want to increase the radius of my
> "celestial sphere" (in order to physically enclose all my objects).
> If I could somehow "clamp" the depth of the star pixels (in screen
> space) to the largest z-buffer value, it would
> seem that the stars would always appear "farther"
> than any other objects in my world. I read the man pages on
> "zbuffer", "zfunction", "zdraw", etc., but didn't find exactly what
> I was looking for. So, is there a way to alter the
> values used for z-buffer calculations for my stars? (or, for that matter,
> any other suggestions on how to solve this dilemma?)
Try:
lsetdepth(getgdesc(GD_ZMAX), getgdesc(GD_ZMAX))
when drawing your stars.
This archive was generated by hypermail 2.0b2
on Mon Aug 10 1998 - 17:50:34 PDT