Re: preIsectFunc bad trav matrix

New Message Reply Date view Thread view Subject view Author view

Swaminathan N. (swami++at++evl.uic.edu)
Sat, 19 Apr 1997 11:14:26 -0500 (CDT)

On Wed, 16 Apr 1997, I wrote:

> I guess maybe you are confusing the traversal matrix and the pfDCS matrix. The
> DCS matrix is not applied to the traversal matrix while in pre-callback mode,
> as Mr Leclerc pointed out. Thus your DCS matrix could be changing, but the
> pre-traversal matrix remains identity. I've used trav->getMat(mat) quite
> successfully (meaning, it did what I thought and wanted it do). In fact a code
> stub in preCB_DCS looks like
>
> pfMatrix traversal
> trav->getMat(traversal);
> pfMatrix m;
> pfdcs->getMat(m);
> traversal.preMult(m);

Oops, I just went back and checked and found that the pfDCS matrix (which was
just a scale factor) was in fact included in trac->getMat(). My multiplying
this just squared the matrix. So, now I'm totally confused. Is trav->getMat()
supposed to include the pfDCS's matrix? Is this a bug, programmer error or
just plain stupidity on my part.

Thanks
Swami

 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
v Swaminathan Narayanan ^
v swami++at++evl.uic.edu ^
v Office: 996-3002 ^
v Home: 850-2726 ^
v http://www.evl.uic.edu/swami ^
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

=======================================================================
List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
            Submissions: info-performer++at++sgi.com
        Admin. requests: info-performer-request++at++sgi.com

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:55:05 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.