# Incorporating a 3x3 rotation matrix into a vtkTransform

S.N.Holt at rl.ac.uk S.N.Holt at rl.ac.uk
Mon Jan 17 11:48:10 EST 2000

```I've assumed your dealing with 2D (its 3x3), so the matrix should be:

T = a b 0 c
d e 0 f
0 0 1 0
g h 0 i

Steve.

> -----Original Message-----
> From: Tim Hutton [mailto:T.Hutton at eastman.ucl.ac.uk]
> Sent: Monday, January 17, 2000 4:09 PM
> To: vtkusers at gsao.med.ge.com
> Subject: Incorporating a 3x3 rotation matrix into a vtkTransform
>
>
> vtk users,
>
> Simple question, I'm a bit rusty with my 4x4 transformation
> matrices. I
> have a routine that computes the  rotation required to LS
> align two sets of
> points. It returns a 3x3 rotation matrix, how do I add this to a
> vtkTransform. Is it as simple as adding a row of 1's?
>
> ie.
>
> R = a b c
>     d e f
>     g h i
>
> T = a b c 0
>     d e f 0
>     g h i 0
>     1 1 1 1
>
> Or is it more complicated?
>
> Cheers,
>
> Tim.
> --------------------------------------------------------------
> -------------
> Tim Hutton, Research Assistant            Email:
> T.Hutton at eastman.ucl.ac.uk
> MINORI Project
> http://www.eastman.ucl.ac.uk/~dmi/MINORI
> Dental and Medical
> Informatics                   Tel: [+44] (0171) 915 2344
> Eastman Dental Institute, UCL                    Fax: [+44]
> (0171) 915 2303
> 256 Gray's Inn Road, London WC1X 8LD, UK
> --------------------------------------------------------------

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