[vtkusers] Want to do 3DOF orientation with vtkGlyph3D

[David Gobbi]

Hi Chris,

I can think of a couple ways that the glyph mapper could be changed to
achieve this.

The best, I think, is to allow the orientation array to have more
than three parameters.  So if you use SetOrientationArray() to specify
an array with:
9 parameters - interpret as a tensor and do an affine transformation
4 parameters - interpret as a quaternion and do a 3DOF orientation
3 parameters - use the current behaviour

Another way would be to allow more orientation arrays to be set,
i.e. add a SetOrientation2Array() method, where by default this
second orientation array would be the NORMALS array.  It would
be hard to make this backwards-compatible, though.

These are all just hypothetical.

 - David


On Wed, Mar 23, 2011 at 2:08 PM, Chris Volpe ARA/SED <cvolpe at ara.com> wrote:
> It appears that vtkGlyph3D allows one to orient glyphs that have (nominal,
> at least) symmetry around one axis, such as vtkCone. What if I want to apply
> a full 3DOF orientation matrix for each glyph at each point? I realize that
> specifying both a position and orientation at each occurrence of a glyph can
> be achieved by using a separate actor for each one, but last time I
> encountered this situation, VTK incurred a substantial performance penalty
> when using a large number of actors. And since I don’t need any of the other
> features of multiple actors (e.g. separate material properties), I’d like to
> avoid doing so if there’s a practical alternative. Any suggestions?
>
>
>
> Thanks,
>
>
>
> Chris
>
> --
> Christopher R. Volpe,
> Ph.D.                                                           Email:
> cvolpe at ara.com
>
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