[vtkusers] Objects disappear

[Martin Saturka]

Wow, I have just tried to compile Cone6.cxx. The Cone6 executable
works fine. And I can see more bad things on the Tcl/Tk version
(dimension changes move the cone reversely to the boxWidget).
Ugh, there is memory fault during program (c++ version) exiting:
---
/vtk-4.2.2/Common/vtkObjectBase.cxx, line 63
Trying to delete object with non-zero reference count.

Memory fault
---
It looks, my problem is between VTK and Tcl/Tk. According to FAQ,
the VTK of 4.2 version should be OK with Tcl/Tk 8.4. It is not.
Below line below is my answer I wrote just before c++ version
attempt.


----------------------------------------------------------------
I just use the VTK example. Thus I do not manage usage of
vtkLODActor, vtkRenderer, etc.

I have an ancient computer (200MHz Pentium, XServer with glint
driver). I revealed that it is much less severe on another
computer, I use too (Linux/Debian on an Athlon, XServer with
r128 driver). As far as I understand, 3D graphics is software
rendered with it. (I am not graphics guy, I just look for sw
to reasonably visualize computation results, and I like Tcl.)

On the Athlon, the disappearance is much less frequent with
usage of "wish8.4 Cone6.tcl" than "vtk Cone6.tcl", both of
them using shared libraries. It looks to me that there are
some race conditions which are much frequent on slow computers.
May be, it is caused by Mesa or whatever, I do not know.


> > Step6/Tcl/Cone6.tcl. If I touch the boxWidget, the cone tends
> > to disappear. Sometimes the cone appears again, but it is not
>
> I can't reproduce the problem here on my RedHat linux box.
> A few things though:
>
> 	- make sure you are not using vtkLODActor
> 	- make sure to call  vtkRenderer::ResetCameraClippingRange


Martin Saturka