[vtkusers] Rotating around the center of an object

[Alex Malyushytskyy]

It rotates according to transformations you define.
Rotation is defined about coordinate origin,
If you need rotate about arbitrary point,
you have first translate (object) so that point appears at the origin,
rotate, then translate back.
something like below:


	vtkSmartPointer<vtkTransform> translation =
vtkSmartPointer<vtkTransform>::New();
			translation->PostMultiply();

			translation->Translate( -center[0], -center[1], -center[2] );
  .................rotate
			translation->Translate( +center[0], +center[1], +center[2] );

Alex

On Wed, Jan 11, 2012 at 12:04 PM, David Brayford <dbrayford at gmail.com> wrote:
> Hi,
>
> I have a scene containing a 3D object and when I rotate the object
> with vtkTransform it rotates around the center of the scene and not
> the center of the object. In OpenGL I would apply the rotation to the
> object within a pushMatrix and popMatrix, but not sure I can do this
> in vtk.
>
> However, I was wondering if I can set the rotation center of the
> vtkTransform to that of the 3D object (which I know)?
>
> Thanks
> David
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