Re: Sorted transparent billboards
John Rohlf (jrohlf++at++tubes)
Mon, 12 Dec 94 12:03:11 PST
>
> >
> > I have had similar problems with PFTR_NO_OCCLUDE. I had geosets that
> > had a PFTR_NO_OCCLUDE flag in the Geostate and they occluded other geometry.
> > When I use gltrace and glfprof, (gltrace produces OpenGL calls) there is
> > no glDepthmask(GL_FALSE). Isn't that what there should be for a NO_OCCLUDE?
> > --
> >
> > Sean Halliday
> > Computer Graphics Software Developer
> > New Media Research, Banff Centre for the Arts.
> > halliday++at++BanffCentre.AB.CA
>
> NO_OCCLUDE is supposed to set zwritemask(0). Looking at the
> code I do see a possible bug if you are using decals, i.e., pfLayers,
> since decals will reenable zwritemask. Does anybody have a
> simple test case which I can debug? Perhaps I should come visit you
> and chase this bug personally even though I hear Banff is a dump. 8-)
Note that even with PFTR_NO_OCCLUDE set, transparent geometry
*will* occlude opaque geometry. The PFTR_NO_OCCLUDE flag should
really be called PFTR_NO_OCCLUDE_OTHER_TRANSP. Perhaps you are
experiencing a feature, not a bug? However, your gldebug trace should
reveal a zwritemask(0) call.
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on Mon Aug 10 1998 - 17:50:44 PDT