HELP!!! transform from UCS to WCS

[Anonymous]

Anyone,

I need to transform an object from a UCS to WCS so that I can accurately get the bounding box of the object.

So for I have taken the matrix returned by the .getUCSmatrix method and inverted it using various functions. This seems to work fine when the UCS is only a coordinate shift without rotation. When the UCS is rotated with respect to the WCS the inverted matrix fails...

Any ideas ?

Thanx in advance to all...

CC

[Anonymous]

Are you sure that your various functions for inverting the matrix are
correct? Have you checked it by inverting the matrix in Excel or Mathcad or
some other program and comparing the answer?

Is the matrix inverse of the UCSmatrix the correct way to get from the UCS
back to the WCS? I'm not doubting, it's just been a while since I had
matrix math.

BTW, I found an extensive discussion of the 3D Transform Matrix at
http://www.makegames.com/3drotation/

Sorry... all questions, no answers... but I would suggest checking your
inversion math for a rotated UCS if you haven't already done that.

James