Rotation in Azimuth bug?

Lisa S. Avila lisa.avila at kitware.com
Mon Jan 24 14:55:59 EST 2000


Hello David,

I believe the main "problem" is that when you do :

[ren1 GetActiveCamera] Elevation 90

you now have both your view up vector and your view plane normal pointing
in the same direction. Camera rotation methods are applied only to the view
plane normal - the view up vector remains the same. If you want to
recompute a new view up vector that is orthogonal to the view plane normal,
you should call:

[ren1 GetActiveCamera] OrthogonalizeViewUp

When you interact in the window, the interactor automatically makes this
call after every rotation.

Lisa

At 01:13 PM 1/24/00 +0930, David J. Netherway wrote:
>Hello,
>
>I was trying to set the initial orientation of the "headsq/half" data
>set to a right sagittal view.
>Attached is a slight variant of the volSimple.tcl demo program from
>"vtk/graphics/exampleTcl". The two lines
>
>[ren1 GetActiveCamera] Elevation 90
>[ren1 GetActiveCamera] Azimuth -90
>
>were added to set the initial orientation.
>
>The anomaly is that azimuth rotations are in the roll direction!
>
>Start the program, and without clicking on the window bring up the user
>intertactor by typing "u" with the mouse over the window. Repeatedly
>issue the following command in the interactor to rotate the camera:
>
>[ren1 GetActiveCamera] Azimuth -5; renWin Render
>
>The rotation is about the roll axis.
>
>Now single click in the widow and repeat the above command - the
>rotation is now about the correct axis.
>
>Would you please explain what is happening here?
>
>David Netherway
>
>
>
>
>
>
> 



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