[vtk-developers] Re: [vtkusers] problem with vtk3DWidgets and observer order

Prabhu Ramachandran prabhu at aero.iitm.ernet.in
Tue May 14 06:59:41 EDT 2002

>>>>> "CPB" == Charl P Botha <c.p.botha at its.tudelft.nl> writes:

    CPB> On Tue, May 14, 2002 at 08:45:21AM +0200, Robert Belleman
    CPB> wrote:
    >> It's broken here; I have camera movemement. Even worse: if I
    >> move one of the balls, the camera moves a little, then all
    >> interaction freezes.  Vtk then consumes 99% CPU.
    >> May 13th nightly.

    CPB> Thanks for testing Rob!

    CPB> Okay, it's working for John and Sebastien and it's broken for
    CPB> you, me and Prabhu.  I'm also working with a CVS checkout of
    CPB> May 11 / 12.  I've also seen the interaction freeze, and so
    CPB> has Prabhu.  Common denominators: I believe John and
    CPB> Sebastien are testing on Windows; Rob, Prabhu and I are on
    CPB> Linux.

    CPB> Any more testers?

FWIW, I just tested again under Debian GNU/Linux (woody) with the
latest CVS checkout and have exactly the same problem reported by you
and Rob (i.e. camera moving + CPU going to 99%).

$ python -c "import vtk; print vtk.vtkVersion.GetVTKSourceVersion()"
vtk version 4.1.1, vtk source $Revision: 1.1215 $, $Date: 2002/05/14 02:47:00 $ (GMT)

So this is a problem.  Note: I did a clean rebuild (make clean; make).

I also found that there is another wierd (not trivially repeatable)
problem with the RenderWindowInteractors in general.  Simply create a
sample example (one attached below) that uses a
vtkRenderWindowInteractor (of any sort) and then hit 't' and 'j' along
with random interactions thrown in and I get a segfault! :( Here is a
backtrace.  As I said, its not easy to replicate.  Just kit a random
sequence of 'j' and 't' and interact with the window.

>>> execfile('t.py')
(no debugging symbols found)...(no debugging symbols found)...
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1024 (LWP 27204)]
vtkSubjectHelper::InvokeEvent (this=0x821db80, event=21, callData=0x0, 
    self=0x81982e0) at /skratch/prabhu/vtk/cvs/VTK/Common/vtkObject.cxx:457
457         next = elem->Next;
Current language:  auto; currently c++
(gdb) back
#0  vtkSubjectHelper::InvokeEvent (this=0x821db80, event=21, callData=0x0, 
    self=0x81982e0) at /skratch/prabhu/vtk/cvs/VTK/Common/vtkObject.cxx:457
#1  0x404f51be in vtkObject::InvokeEvent (this=0x81982e0, event=21, 
    callData=0x0) at /skratch/prabhu/vtk/cvs/VTK/Common/vtkObject.cxx:581
#2  0x41c94483 in vtkXRenderWindowInteractorCallback (client_data=0x81982e0, 
    at /skratch/prabhu/vtk/cvs/VTK/Rendering/vtkXRenderWindowInteractor.cxx:629
#3  0x41e583ff in XtDispatchEventToWidget () from /usr/X11R6/lib/libXt.so.6
#4  0x41e58d7e in _XtOnGrabList () from /usr/X11R6/lib/libXt.so.6
#5  0x41e58fc8 in XtDispatchEvent () from /usr/X11R6/lib/libXt.so.6
#6  0x41c929a8 in vtkXRenderWindowInteractor::Start (this=0x81982e0)
    at /skratch/prabhu/vtk/cvs/VTK/Rendering/vtkXRenderWindowInteractor.cxx:165
#7  0x4190232c in PyvtkXRenderWindowInteractor_Start (self=0x821de48, 
    at /skratch/prabhu/vtk/cvs/VTK/Rendering/vtkXRenderWindowInteractorPython.cxx:322

Its not really a vtkXRenderWindow bug because it happens with the new
widgets that I added last night as well.

Here is my test code:

# ----------------------------------------
from vtk import *

ren = vtkRenderer()
renWin = vtkRenderWindow()

iren = vtkRenderWindowInteractor()

# create an actor and give it cone geometry
cone = vtkConeSource()
coneMapper = vtkPolyDataMapper()
coneActor = vtkActor()

# assign our actor to the renderer

# enable user interface interactor

# ----------------------------------------


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