Hi J.P.,

with
#define USE_EFFECT SILT
I get the gray screen in added view on 3rd 'a'.

Thanks for testing, that's what I saw too on Ubuntu. I expect if you use USE_EFFECT PRECIPITATION you'll see the same results.

Hmm, what is strange is that the modified (extremely hacky) version attached does not crash and seems to work. It just uses a shared context, so maybe there is something in the context vs vertex array that is not working properly.

Yes, well one of my hunches was that something in the context creation/reuse was buggy, since the problem appears because we're creating, then deleting, then creating contexts. I've traced into the code of the effect, and the same context ID seems to be reused the second time the secondary view is created (3rd 'a') as the first time (1st 'a'). That means that when getting the osg::Drawable::Extensions object, the same one that was created for the old context is reused for the new context.

But that apparently isn't the problem, because if I force the Extensions object to be destroyed when the secondary view is closed (so that the next time it's spawned, a new Extensions object will be created) like so:


// In doRemoveView(), between the stopThreading() and startThreading()
unsigned int contextID =
  _view->getCamera()->getGraphicsContext()->getState()->getContextID();
_viewer->removeView(_view.get());
_view = 0;
osg::Drawable::setExtensions(contextID, 0);


it doesn't remove the crash.

Also, I tried to make the scene delete all its OpenGL objects for all contexts, like so:


  // Again in doRemoveView() before the startThreading()
  _root->releaseGLObjects();


and it doesn't fix it either.

So yes, it's probably related to the creation/deletion/reuse of contexts or context-specific objects, but I haven't been able to pinpoint it yet to something that's wrong in OSG itself.

If anyone else would like to take up the challenge of explaining this mystery, please step up :-)

Thanks,

J-S
--
______________________________________________________
Jean-Sebastien Guay    [email protected]
                               http://www.cm-labs.com/
                        http://whitestar02.webhop.org/
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