Re: Changing the position of the sun

New Message Reply Date view Thread view Subject view Author view

Angus Dorbie (dorbie++at++sgi.com)
Wed, 28 Apr 1999 13:57:58 -0700

Rob Body - HR Mardyn wrote:
>
> Hi everyone,
>
> I am new to Performer and am trying to find out how to change the position
> where the sun shines from but I'm not having any luck.
>
> I have looked and changed parameters in env.c but without success.
>
> I am tring to have the sun rise at one side of my world and have it set on
> the other side, changing the time of day correctly so that the sky starts to
> be brighter on the side where the sun rises and darker opposite, then
> gradually get lighter everywhere and the finally as it sets get darker first
> on the side where it rose from.
>
> Does this make sense ??

Yes.

>
> Is it possible ??
>

Yes. There is no high level concept in Performer for such a thing. You
need to implement your own by moving a light source across the sky by
changing it's position and by drawing polygons to represent the sky
radiance to include effects like horizon glow. The earth sky in
performer does a little of th elatter but it is not very sophisticated.

> Any pointers in the right direction will be greatly appreciated.
>

My web page has something on drawing a hemisphere to represent the
'sky' in the Aqua section.

Cheers,Angus.

For advanced 3D graphics Performer + OpenGL based examples and tutors:
http://www.dorbie.com/

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Wed Apr 28 1999 - 13:58:04 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.