From: Florian Berger (florian.berger++at++aec.at)
Date: 10/02/2002 03:11:59
hi there
i have a problem, well actually i have solved it, but...
i want to do the following:
translate a model to the origin,
rescale it by some factor,
translate it somewhere else.
to me this would have to be done that way:
mat.preTrans( -orig[0],-orig[1],-orig[2], mat );
mat.preScale( scale,scale,scale, mat );
mat.preTrans( somewhere[0], somewhere[1], somewhere[2], mat );
but to my surprise, by trying around a bit i figured out that this gives the
desired results:
mat.preTrans( -orig[0]*scale,-orig[1]*scale,-orig[2]*scale, mat );
mat.preScale( scale,scale,scale, mat );
mat.preTrans( somewhere[0]/scale, somewhere[1]/scale, somewhere[2]/scale,
mat );
i know one has to take care of translations combined with scales and such,
and i really thought about it carefully, but the above thing really puzzles
me.
multiplying a translation matrix from the left side should simply add the
translation vector values to the last column, shouldnt it?
thanks in advance, and
never hesitate to argue with success :),
floh
------------------------------------------------------------
Dipl.-Ing. Florian Berger
Email: florian.berger++at++aec.at
Homepage: http://www.geocities.com/harpin_floh
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