Re: fog color
Angus Dorbie (dorbie++at++sgi.com)
Wed, 18 Mar 1998 15:37:36 -0800
Steve Baker wrote:
>
> On Wed, 18 Mar 1998, Angus Dorbie wrote:
>
> > If you change fog color downstream in the draw then you
> > run the risk that the fog color from the app will clobber
> > your results next frame. Not a good plan unless you modify
> > it before drawing _every_ frame. Same goes for other similar
> > info.
> >
> > Modify fog colour in the application process and use
> > multiple fogs if you need variety. Note this needs to be
> > the performer app, not the keyboard process, cull process
> > or draw process, but the application which ran through
> > the pfConfig.
>
> But if your fog changes frequently or suddenly, that change happens
> asynchronously in all channels - which looks terrible. (This
> may have been fixed recently - but this statement was certainly
> true a year or so ago).
>
> Doing the fog change in DRAW fixes *that* problem - but admittedly
> you have to be careful not to try to change it anywhere else
> as well.
>
This seems lika a strange problem ang may have been the result
of a single buffered fog with no MP consideration, it is certainly
more acceptable than the results of a change not taking effect.
You should try fog on an earthsky and see if you still get your sync
bug.
Cheers,Angus.
--
"Only the mediocre are always at their best." -- Jean Giraudoux
For advanced 3D graphics Performer + OpenGL based examples and tutors:
http://www.dorbie.com/
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on Mon Aug 10 1998 - 17:57:02 PDT