Christopher Geyer (cgeyer++at++seas.upenn.edu)
Tue, 12 Aug 1997 10:23:15 -0400 (EDT)
I have made a cull volume which is a subspace of the reflection of the
original culling volume; its facets are planes created by the virtual
viewpoint and the sides of the reflective face, as well as the reflective
face itself. I create this in the pre cull callback of the pfDCS which
contains the reflection transformation. All geometry which has as its
parent this pfDCS should use the new cull volume. So, in the pre cull
callback I push the current culling pfPolytope onto a stack (taken from
pfChannel::getCullPtope) and then set the current culling polytope using
pfChannel::setCullPtope. If I let it run geometry is culled incorrectly.
If I create a custom cull callback for my geomtry which calls
getCullPtope( frust, PF_EYESPACE ) and checks each facet for containment
then it works fine. But if I let Performer do the culling it does not
cull correctly.
What is the order of transformations, if any, that I must apply to my
frustum before calling pfChannel::setCullPtope? I would much rather let
Performer do the culling. In what space does setCullPtope assume I'm
passing it a frustum? And is that the same at the pfDCS callback?
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/
=======================================================================
List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
Submissions: info-performer++at++sgi.com
Admin. requests: info-performer-request++at++sgi.com
This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:55:43 PDT