From: Radomir Mech (rmech++at++cthulhu.engr.sgi.com)
Date: 09/17/2003 13:24:46
Michael Petrou wrote:
>
> > -----Original Message-----
> > From: David Lannan
> > Sent: Wednesday, 17 September 2003 1:19 PM
> > To: Michael Petrou
> > Subject: Usage of setCullPolytope()
> >
> > Questions about using Performer 2.2
> >
> > 1. We are using Performer 2.2, due to software integration restrictions. I
> > would like to know if there is an equivalent way to implement
> > pfCullPrograms (which are implemented in 2.5 and above). Ideally the
> > example of occlusion culling suggested in the Performer 3.02 manual would
> > need to be implemented in version 2.2.
> >
The only way would be to use cull callbacks but it would not be
trivial.
> > 2. I have been using setCullPtope() and its behaviour appears to be a
> > little odd. Is this function simply and implementation of setting the view
> > frustum? Is there a way to specify cull behaviour within a particular
> > polytope? Currently all objects outside the polytope are culled - this
> > seems to be just a frustum cull implementation.
> >
Function setCullPtope is a pfChannel function and it sets the regular
view frustum polytope. Polytopes used by pfCullProgram are set using
pfCullProgram::setNumPolytopes and pfCullProgram::setPolytope.
> > 3. Is there any way to flag a node to be explicitly culled during a custom
> > cull process? Setting the cull mask only determines whether the cull
> > process should traverse the node, not whether it should/shouldnot be
> > culled from being drawn - must the draw mask be set appropriately for this
> > to work? Can you cull a node without using a draw mask and without
> > removing the node from the scenegraph?
> >
Again, you can use cull callback in 2.2.
Radomir
> > David Lannan
> >
>
> -----------------------------------------------------------------------
> List Archives, Info, FAQ: http://www.sgi.com/software/performer/
> Open Development Project: http://oss.sgi.com/projects/performer/
> Submissions: info-performer++at++sgi.com
> Admin. requests: info-performer-request++at++sgi.com
> -----------------------------------------------------------------------
This archive was generated by hypermail 2b29 : Wed Sep 17 2003 - 13:25:14 PDT