Selecting objects and PickData problem

["Richard Tyc" <richt(at)sbrc.umanitoba.ca>]

I am trying to get object selection (and ultimately manipulation
interactively)  to work properly without much success.

I understand from previous postings and David Fannings example that the
method first requires:

1) perform a  selObj = oWIndow->Select ( oView, [sEvent.x,sEvent.y] )
operation to get the list of objects which could be picked from.

2) Assuming my object of choice is in the list (I check on the NAME property
for each object which I have previously assigned), I can then do something
like

 pick = oWindow->PickData( oView, pickObj, [sEvent.x,sEvent.y], dataxyz)

My problem is that the PickData method does work ( ie. the right pickObj is
found from the original selection list) but the actual data in dataxyz makes
no sense!!  My object of choice, an IDLgrPolyLine, is part of oModel
contained in oView which has been transformed.  I display the X,Yand Z axis
on screen when I manipulate the Model (using oTrackball type interaction)
but the PickData returns data outside my bounds ie. the entire polyline is
within positive X,Y,Z but yet dataxyz returns negative positions ?
Does dataxyz not have the correct transformed data ? Is there a bug here ?

I am trying to allow the user to interactively grap the end point of a line
and modify its position by moving the mouse.

Thanks

Rich