[vtkusers] Deep copy of vtk Object vtkModifiedBSPTree

[Normand Robert]

Hi John

Thank you for your reply. Please let me make sure I understand your 
statement by asking a question: Are you saying that only the first call to
bspTree->IntersectWithLine(P1, P2, tolerance, points, cellIds); should 
be protected because some allocations or other housekeeping occurs and 
that subsequently many threads can call IntersectWithLine() at the same 
time?

Regards

N.


On 15-12-03 02:54 AM, Biddiscombe, John A. wrote:
> Making copies of the tree is a very bad idea as the locator stores a lot of extra info for accelerating ray-traces.
>
> If you could send a stack trace of where you are getting errors I might be able to suggest something. I had a quick look over the intersection code (which I wrote originally back in 1997 or thereabouts - so I'm a bit rusty with it) but I do not see any obvious misuses of vars. The initial build tree is not thread safe, so you should ensure that two threads are not calling the first ray intersection simultaneously if buildtree has not already been called.
>
> JB
>
> -----Original Message-----
> From: vtkusers [mailto:vtkusers-bounces at vtk.org] On Behalf Of Normand Robert
> Sent: 01 December 2015 04:07
> To: vtkusers at vtk.org
> Subject: [vtkusers] Deep copy of vtk Object vtkModifiedBSPTree
>
> Hi
>
> I wish to use vtkModifiedBSPTree with OpenMP by making copies of vtkModifiedBSPTree instances local to each thread but there does not seem to be any methods to copy this object. I naively thought that all vtk objects would have ShallowCopy() or DeepCopy(). I have to do this because using IntersectWithLine() in different threads for the same object instance causes crashes. Is there a solution to this?
>
> Regards
> Normand Robert PhD
> Sunnybrook Research Institute
> University of Toronto
>
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-- 
Normand Robert PhD
Sunnybrook Health Sciences Centre
Room S632, 2075 Bayview Avenue, Toronto, ON M4N 3M5