Steve Baker (steve++at++mred.bgm.link.com)
Wed, 16 Apr 97 08:26:43 -0500
> The node used to set the traverser CB is a pfDCS with a changing matrix,
> The result of printing is an Ident matrix instead of the dcs matrix at
> ISECT time.
>
> Am I making a mistake or its a Performer bug?
I think it's a pfBug. I reported a similar problem some time ago - but
didn't get any kind of response. Eventually I found a work-around.
Here is the note I wrote to myself at the time (over a year ago)...
/*
SJB: There is some kind of a bug in pfGetTravMat(). In this application,
there is typically a DCS node somewhere above this node and
pfGetTravMat() is well behaved. However, if there is no DCS
(or maybe an SCS?) between the pfScene and this node then
pfGetTravMat() should return an identity matrix. In fact, the
X and Y eyepoint coordinates can be found in the bottom row
of matrix - but curiously, not the Z coordinate!?!
*/
[pfGetTravMat() and pfTraverser::getMat() are of course the same routine.]
If what I discovered back then is still true, then you *might* be able to
work around the problem by putting a DCS (or perhaps an SCS) at some
point in the tree above the node with the preIsectFunc() callback.
My code (as it happens) always has a DCS node somewhere above the node with
the callback - clearly when I wrote that comment, I believed that an SCS
might work instead.
It would be nice if some kind hearted pfPerson would fix this problem in
Perf 2.2 or in a patch to 2.0.x/2.1.x
I hope this helps...
Steve.
Steve Baker 817-619-1361 (Vox-Lab)
Hughes Training Inc. 817-619-8776 (Vox-Office/Vox-Mail)
2200 Arlington Downs Road 817-619-4028 (Fax)
Arlington, Texas. TX 76005-6171 Steve++at++MrEd.bgm.link.com (eMail)
http://www.hti.com (external) http://MrEd.bgm.link.com/staff/steve (intranet)
http://web2.airmail.net/sjbaker1 (external)
"You can't destroy the Earth - that's where I keep all my stuff!" - The Tick.
=======================================================================
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 - 17:55:04 PDT