[vtkusers] Picking questions

Sherwood, P (Paul) P.Sherwood at dl.ac.uk
Fri Oct 25 04:55:04 EDT 2002

Prabhu and all,

>>  >>>>> "PS" == P Sherwood <Sherwood> writes:
>>      PS> I am still keen to hear if anyone has any ideas on my other
>>      PS> question, how to implement a "rubberband type" multiple
>>      PS> selection.
>>   1. Find the co-ordinates of the rubberband box
>>   2. sample a whole bunch of points (random or regular) in that box.
>>   3. Do a pick for each of those points and find the object picked.
>>   Store if the object has not been picked already.

Thanks for the suggestion. 

I wondered about this approach, but I am worried about the 
cost of lots of pick calls .. and I expect lots will be needed
to make sure no parts of the scene are missed and the rectangle
is fully sampled. The scene may be very complex and it could
be a major disaster of one of the elements (atoms) escapes the

It would seem to be a feature that would be best built into
the vtk core somehow, but to be realistic I probably don't
have the skills (or right now, the time) needed to do this.
Maybe I could help at some time in the future with the support
of someone who understands the current picking code. I understand
from Will that there will be some vtk folks at SC 2002 so maybe
we can talk it through then.


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