Stress and Stats.

New Message Reply Date view Thread view Subject view Author view

Steve Baker (sbaker++at++link.com)
Fri, 28 Aug 1998 09:56:18 -0500 (CDT)


Hi!

  This is kindof urgent - so if there is a pfPerson listening, I'd
appreciate a quick answer.

  I recently turned on Stress management on a system that didn't
previously use it and was suprised to find that pfChanStressFilter
was only effective when I had enabled stats gathering.

  Imagine my frustration:

USER: Steve - your stress code doesn't work.
STEVE: Hmm - I'll turn on statistics and see what's happening.
       ...See - stress works just fine.
USER: No it doesn't.
STEVE: Yes it does...look how the polygon count stays roughly
       constant...it says so right here in the stats....
       (ad nausiam)

If I use something like:

  pfFrameStats *fsp = pfGetChanFStats ( chan ) ;
  pfFStatsAttr ( fsp, PFFSTATS_UPDATE_FRAMES, 60 ) ;
  pfFStatsClass ( fsp, PFSTATS_ENGFX, PFSTATS_SET ) ;

...stress functions nicely.

But if I do this:

  pfFrameStats *fsp = pfGetChanFStats ( chan ) ;
  pfFStatsClass ( fsp, PFSTATS_ALL, PFSTATS_OFF ) ;

...then stress management seems to be disabled.

...I can find no mention in the man pages that pfChanStressFilter
requires stats gathering to be enabled - although I could perhaps
understand why Performer might need that to be done in order to
measure the stress.

So, my questions are:

1) Am I dreaming or is this really true?

2) Is this considered a bug or just a documentation drop-off?

3) Since stats collection (presumably) takes time, what is the
   most efficient/minimum required stats collection modes for
   stress management to work properly. Maybe PFSTATS_ENGFX
   is overkill.

4) Since I normally set the pfFStatsAttr to average stats over 60
   frames (1 second), am I also causing the stress management
   filters to see stress levels over a 1 second window instead of
   reacting immediately?

5) If it's a bug, is there a better work-around than turning stats
   collection on?

Oh, yes - I do mean the pfLOD-range-modification kind of stress
management - not DVR.

Steve Baker (817)619-2657 (Vox/Vox-Mail)
Raytheon Systems Inc. (817)619-4028 (Fax)
Work: SBaker++at++link.com http://www.hti.com
Home: SJBaker1++at++airmail.net http://web2.airmail.net/sjbaker1


New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Fri Aug 28 1998 - 15:59:29 PDT

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