[vtkusers] Tcl_HashEntry???

Will Schroeder will.schroeder at kitware.com
Wed Feb 21 08:52:18 EST 2001

At 02:36 PM 2/21/2001 +0100, kitware-vtk at kulnet.kuleuven.ac.be wrote:

>PS: Why the hell is the default picker changed to a vtkPropPicker
>instead of a vtkPicker???
>How can I get a dataset from that vtkPropPicker? Previously i used:
>        [[[$wndRenderWindow GetInteractor] GetPicker] GetDataSet]
>but of course this doesn't work anymore because the default picker is
>now vtkPropPicker!

Picking was changed in vtk because it didn't work correctly for assemblies, and because
it used software ray casting instead of hardware picking (it was slow). vtkPropPicker
will use picking hardware. Also, vtkPicker selects the vtkProp whose bounding box
intersects the ray defined from the camera position and the selection point. This does
a very poor job of picking the right thing when you have more than a few objects on
the screen.

You can easily fix this by manually creating a vtkPicker and setting this as the 
Picker to vtkRenderWindowInteractor. Then the behavior will be as before. Or, if
you want to upgrade to vtkPropPicker, you can do a GetActor(), then get its mapper,
and then get its input (dataset).


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