vtkTransform

[Ron Inbar]

The default mode for vtkTransform is PreMultiply.  Nevertheless, methods
like Translate and Rotate* set the matrix in a way suitable for
Post-Multiplication.  This results in the following peculiarities:

vtkTransform xform
xform Translate 10 20 30
xform SetPoint 0 0 0 1
xform GetPoint
=> 0 0 0
# I expected to get {10 20 30}!
xform Identity
xform RotateZ 90
xform SetPoint 1 0 0 1
xform GetPoint
=> 0 -1 0
# instead of {0 1 0}

Everything works as expected once xform is set to PostMultiply.  Is there a
reason for this behavior or is it just a legacy bug which is too late to fix
now?  That would be a shame!

RSVP,

Ron




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