[vtkusers] Setting Camera/Focal Point Orientation

[Michael Rice]

This is what I thought. I just want to make sure I'm not missing something,
like some other camera, renderer or interactor subclass(es) that keep track
of the parameters.

Michael

On Mon, 16 Oct 2006 07:52:45 +1000, "Andrew Maclean"
<andrew.amaclean at gmail.com> wrote :

> 
> Hi Michael,
> 
> I think the simplest explanation is that these values are compounded into
> the homogenous matrix that directly specifies the orientation. As such
> because the homogenous matrix is the product of one or all of these values
> plus any other orientation/rotation/translation values it will never be
> possible, except in very simple single parameter cases, to extract out the
> entered values from the homogenous matrix.
> 
> In general it is very difficult because of angle ambuguities and also
> because the rotation axis may not be coincident with the cartesian axes to
> extract these values.
> 
> 
> Andrew
> 
> 
> 
> 
> 
> On 10/16/06, Michael Rice <marice at knology.net> wrote:
> >
> > After looking at the vtkCamera, I see there are methods to adjust the
> > Elevation, Azimuth, Roll, Yaw, and Pitch. These appear to function as
> > offsets from the current value, but I don't see functions to get
> > these values - other than Roll. Also, there is a SetRoll function to
> > set the absolute roll value, but there aren't functions to set the
> > absolute angles for the other values.
> >
> > I guess I have 2 questions:
> >
> > 1. Why aren't there functions to get/set the absolute values for
> > elevation, azimuth, yaw, and pitch?
> >
> > 2. Are there other VTK methods or sample code that returns these values?
> >
> > Thanks.
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> 
> 
> 
> -- 
> 
> ___________________________________________
> Andrew J. P. Maclean
> Centre for Autonomous Systems
> The Rose Street Building J04
> The University of Sydney  2006  NSW
> AUSTRALIA
> Ph: +61 2 9351 3283
> Fax: +61 2 9351 7474
> URL: http://www.cas.edu.au/
> ___________________________________________
> 
>