Angus Dorbie (dorbie++at++multipass.asd.sgi.com)
Thu, 26 Jun 1997 16:20:39 -0700
Cheers,Angus.
On Jun 26, 7:17pm, Christopher Geyer wrote:
> Subject: Re: pfDraw() in channel draw callback
> > What are you trying to draw in the pfDraw and in your display lists?
>
> I'm trying to draw a shadow volume; the display list contains the shadow
> volume for my scene from a light, and is created in the cull stage.
>
> I create it by setting a post & pre cull function for all the nodes
> (pfGeodes) which contain a shadow volume (that's all they contain). In
> the pre function I close the current display list and open the display
> list that I've created for the shadow volume. In the post function I
> close that display list and re-open the previously current one (the same
> one closed in the pre function).
>
> > Without more detail I'd suggest a pushmatrix and popmatrix either side
> > of the pfDraw would probably be a good idea.
>
> I've used gldebug and it shows that pushmatrix is successfully called by
> pfDraw() and so is popmatrix, at the end.
>
> It seems that my display list somehow is emptied, because no GL graphics
> commands are executed if pfDraw() has been called before. Either it's
> emptied for some strange reason or it just doesn't let it get drawn.
>
> Even stranger, if in the stage after which I've now created my shadow
> display list, and after I've re-opened the current display list, I add
> that shadow volume display list (i.e. do shadowVolDL->draw() while the
> display list is open) it correctly draws that shadow volume as part of
> the scene; it ALSO draws the shadow volume when I tell it to draw the
> shadow volume display list, whereas before it wouldn't.
>
> BTW, I'm using an O2, R5000.
>
> Christopher
>
> ----------------------------------------------------------------------------
> Christopher Geyer | CompSci and Math '99 at the University of Pennsylvania
> 215-732-4218 | cgeyer++at++seas.upenn.edu | http://www.seas.upenn.edu/~cgeyer/
>-- End of excerpt from Christopher Geyer
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