[vtkusers] Picking points from multiple surfaces.

[Donna Hanlon]

An Jiye wrote:
 >But I have some questions about this picker.
[snip]
 >Can you explain me how opacity influnce the picking result?

I wish I could, but I don't know the answer.  The vtkPropPicker's 
superclass is vtkAbstractPropPicker, described here:

http://www.vtk.org/doc/nightly/html/classvtkAbstractPropPicker.html

The detailed description says:

>  The class returns information about picked actors, props, etc. Note that what is returned by these methods is the top level of the assembly path. This can cause a lot of confusion! 

But whether this has anything to do with your problem, I can't say.

 >I have no Computer Graphics background. I will learn it later.

Then you can teach me. ;-)

Donna