Re: Onyx to Onyx2 Problem - pfSegSet

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Angus Dorbie (dorbie++at++sgi.com)
Fri, 14 Aug 1998 11:31:45 -0700

Perhaps the problem is the face winding of the database polygons.
Intersection tests will check face winding and eliminate back faces
if told. This would be irrespective of the visible state information.

It may be something more obvious like intersection traversal masks.

Cheers,Angus.

Pete Willemsen wrote:
>
> Hello Again.
>
> We have an application in which we use the pfSegSet to determine the
> height and normal of the terrain. When we run this application on
> either our Onyx iR (2RM) or our Indigo2 Impact the intersections work
> fine for all of our databases.
>
> However, we recently had to run this application on an Onyx2 iR (2RM),
> and so, to help the port, I statically linked our application to the
> Performer libraries on our Indigo2 Impact.
>
> When we run one of our databases with this performer application on
> the Onyx2, the pfHits and pfSegSet work fine (hits returning greater
> than 0).
>
> But, when we run the same application with a different database, the
> pfHit count returns 0.
>
> I'm confused by this behavior since the application and all databases
> give the correct height and normal values when run on our Onyx and
> Indigo2. Any ideas as to what might be causing this?
>
> (We do not have the option to recompile on the Onyx2 - also, just for
> your knowledge, I did try our application with dynamic linking, but we
> had the same results).
>
> Pete
> ----------------------------------------------
> Pete Willemsen Department of Comp. Sci.
> willemsn++at++cs.uiowa.edu University of Iowa
> ---
> http://www.cs.uiowa.edu/~willemsn
> ----------------------------------------------
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