Lance R. Marrou (marrou++at++vsl.ist.ucf.edu)
Thu, 3 Nov 1994 18:23:40 -0500 (EST)
> > msg.articulatedParts[i].parameterValue1 - .05 &&
>
> One minor thing here, the lack of an 'f' as in .05f causes
> parameterValue1 to be promoted unnecessarily to double precision.
> ALWAYS use an 'f' in your single precision FP constants.
This is something I didn't know. I thought the ANSI specification was
to have the literal take the type of the variable, if possible. Thus,
if parameterValue1 was float, .05 would be float. Oh well, not too
hard to put an "f" behind all my literals! :)
BTW, am I right in remembering the degree fidelity in GL and thus Performer
is 1/10 of a degree (thus the .05 for smooth transitions between tenths
of degrees)?
>
> As for the basic question of doing offset rotations, we're thinking of
> adding a rotation center to DCSes for the next release.
Cool!
> For now, the most efficient way to generate the matrix is to use paper
> and pencil to work out just what you need. The Euler*Trans is trivial
> and certainly doesn't require a full matrix multiply even in the
> general case.
... (matrices not repeated)
For some reason this slipped me. However, the followup question to this
direct method of matrix generation would be what method to generate the
cosines and sines? Standard Performer library calls? Is that what
MakeEulerMat does?
> Hopefully, I got the signs right ;-).
I will redo the math and check it :)
Back onto the subject. I have thought of another way to generate the
right matrix. If I store the movable parts in separate files, basing
the origin in each one as the rotation point, I can skip the translation
part of the calculation. However, this would require too much trouble
in handling more files for each vehicle type (puke).
Also, I could use pfMakeRotMat if I know the axis of rotation. I can
pre-compute the axis of rotation (normalized, of course) at load time.
Although I doubt this will be faster than your proposed solution. Bob
Buckley, a friend of mine from here (IST and NTSC) and now somewhere in
Colorado, suggested this one. Is it the solution? (I do not need
multiple DOF for movable parts at one joint yet, but I might in the
near future.)
Thanks for your help!
BTW, y'all in the Performer Team are truly amazing!
_______________________________________________________
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