Re: Selecting objects and PickData problem

[davidf(at)dfanning.com (David Fanning)]

Richard Tyc (richt@sbrc.umanitoba.ca) writes:

> 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.

I don't know, Richard. I haven't tried this particular
thing. But I do see a lot of caveats in the on-line help
for the PickData method, including caveats that you may
have to apply your own data transformations to these
values. Have you read the documentation carefully?

Cheers,

David

-- 
David Fanning, Ph.D.
Fanning Software Consulting
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