[vtkusers] picking + partial success

[Prabhu Ramachandran]

>>>>> "GG" == Gowri Gopalakrishnan <Gopalakrishnan> writes:

    GG> I found the problem with my picking. It was something do the
    GG> with the screen size (similar to the java wrap of vtk). So now
    GG> I can pick my actors.  QUESTION: I am still concerned about
    GG> the GetPointId method. If I had 42 points in my plot,
    GG> picker->GetPointId() - should it be between 0-41 or it is
    GG> vtkgenerated Internal number?. At the moment the getPointId
    GG> returns different numbers depending on if the actor is zoomed
    GG> in or not etc. So how can I use this point id to actually get
    GG> the original data values. The GetPosition gives me the data
    GG> points in someother coordinate system. I want to extract the
    GG> data I put in.

When you pick an actor the id that it returns is the point id
corresponding to that particular actor.  I think the way most people
use the picker is to get the id, get the data set and use the id on
that particular dataset to get the actual values.  As regards the
zooming etc. check the actually picked position using GetPickPosition
(or whatever) and I think you'll see that you dont necessarily pick
exactly the point you intended.  You could put a cursor or something
to locate the point that you picked this way you can be sure of what
is going on.

prabhu