[vtk-developers] 3x3 rotation matrices

[David Gobbi]

On Sun, Jan 10, 2010 at 11:08 AM, David Doria <daviddoria+vtk at gmail.com> wrote:
> On Sun, Jan 10, 2010 at 1:03 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
>> vtk uses homogenous coordinates. Why extract a 3x3?
>>
>> Bill
>
> If you are implementing an algorithm that has a 3x3 multiplication and
> you want to create a rotation matrix. Or for creating a 2d rotation in
> homogeneous (now 3d) coordinates. If there is a Matrix3x3 class, you
> should be able to create common matrices in that type, no?
>
> Thanks,
>
> David D

I think that this method should go in vtkMatrix4x4.  An easy method
for conversion between 4x4 and 3x3 matrices would be a good thing, but
vtkTransform might not be the best place (I'm not strongly against it,
though).

   David G