[vtkusers] rotating vtkCamera

[Mark Wyszomierski]

It did it - so all OrthogonalizeViewUp()  does is make the view up
perpendicular to the focal point vector - makes sense - I guess it
should be the cross product of the focal vector and the vector being
rotated about?

Thanks,
Mark

On 4/19/07, Marc Cotran <marc at cotran.ca> wrote:
> Hi other Mark :)
>
> Try calling vtkCamera::OrthogonalizeViewUp() after each call to
> Elevation(). Although the VTK docs say:
>
> "Recompute the ViewUp vector to force it to be perpendicular to
> camera->focalpoint vector. Unless you are going to use Yaw or Azimuth on
> the camera, there is no need to do this."
>
> I would try it anyway :)
>
> Marc
>
> Mark Wyszomierski wrote:
> > Hi Marc,
> >
> > Elevation seems to work - kind of. I keep calling elevate with the
> > amount of degrees I want to change by:
> >
> >     for (int i = 0; i < 64; i++) {
> >        pCamera->Elevation(360.0 / 64.0);
> >     }
> >
> > It works fine through about a 90 degree rotation - but then I start
> > getting debug error messages about the view up having to be
> > recalculated, and the volume starts spinning around out of control!
> >
> > Thanks,
> > Mark
> >
> > On 4/19/07, Marc Cotran <marc at cotran.ca> wrote:
> >> Hi there,
> >>
> >> Try vtkCamera::Elevation() and Azimuth() - both methods take an angle
> >> parameter. Sounds like you are looking for Elevation(). Pitch(), on the
> >> other hand, changes the focal point, not the camera position.
> >>
> >> hth
> >>
> >> Marc
> >>
> >>
> >> Mark Wyszomierski wrote:
> >> > Hi,
> >> >
> >> > Is there a method of vtkCamera to rotate about the focal point?
> >> > Something like:
> >> >
> >> > for (int i = 0; i < 64; i++) {
> >> >     double dPitch = i * (360.0 / 64);
> >> >     pCamera->Pitch(dPitch);
> >> >     // render..
> >> > }
> >> >
> >> > The effect I'm looking for is to have the camera orbit around its
> >> > focal point in the direction of its view up.
> >> >
> >> > Thanks,
> >> > Mark
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> >>
>
>
>