[vtkusers] Transform axes

[David Gobbi]

Hi Gib,

If I'm reading your question correctly, then what you are looking
for is very easy to achieve.

To transform an object from its canonical x,y,z axes onto a
new set of orthogonal axes, all you need is to set the first three
columns of a 4x4 matrix to those axes.

if the axis vectors are u, v, and w, then the transform matrix is

u_x, v_x, w_x, 0,
u_y, v_y, w_y, 0,
u_z, v_z, w_z, 0,
0, 0, 0, 1

No algebra involved!

 - David




On Wed, Nov 5, 2014 at 5:47 PM, Gib Bogle <g.bogle at auckland.ac.nz> wrote:

>  Hi all,
>
> This is a 3D geometry problem, one that many people must have solved.  I
> want to apply a transform to my actor to bring it's local axes (which are
> initially aligned with the global axes) into alignment with a specified
> triplet of orthogonal vectors.  In fact alignment with a pair is
> sufficient.  I'm hoping that somebody has done this in VTK and can save me
> the trouble of going through the algebra.
>
> Thanks
> Gib
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20141105/3f5d0318/attachment.html>