Frederic Francis (pffred++at++llogic.com)
Thu, 27 Nov 1997 10:52:21 -0500 (EST)
While debugging our multiple scale motion model implementation,
we have discovered that pfChannel::setViewMat(pfMatrix &mat) sets
to zero any entry in the translation part of mat which smaller than
1.0e-7.
This behavior seems to be confined to pfChannel::setViewMat since
altering the pfChannel class definition to allow setting the viewmat
directly makes the truncation disappear.
Why is this done ?
I'm assuming that it might have been done in order to avoid raising
floating point exception flags but I don't see why 1.0e-7 would be
a special threshold for underflow prevention.
Where is this documented ?
Is there a way to bypass or disable this truncation apart from
hacking the pfChannel header ?
Best Regards,
Fred.
__________________________________________________________________
Frederic Francis email: fred++at++llogic.com
Director of Technology phone: 1-514-287-1166
Lateral Logic fax: 1-514-287-3360
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