Hi Robert,
My example code was only meant to show the symtoms of the problem I get it in
my "real world" code. How can I use a composite viewer to implement views
within multiple browser plugin instances, potentially on different web pages?
Would I have to make the composite viewer a singleton that holds references to
the embedded windows created for each plugin instance? It's never gonna fly!
Interesting update to the problem though; it seems not related to the embedding
of the textures within the IVE, but more to do with the way IVE reader creates
images. The reason being that if I convert cow.osg using "osgconv -O
noTexturesInIVEFile cow.osg cow.ive" I still get the problem, but if I load
"cow.osg" into my example, it seems fine.
Chris Denham.
robertosfield wrote:
> Hi Chris,
>
> Using two independent viewers in an application is not normal or
> recommended. I would recommend that you use a single CompositeViewer
> with two Views. See the osgcompositeviewer example.
>
> Robert.
>
> On 13 January 2012 14:18, Chris Denham <> wrote:
>
> > I'm having some problems connected with the use of textures embedded within
> > IVE files. The problem arises when I use the same IVE model instance from
> > within two instances of osgViewer::Viewer which results in unpredictable
> > rendering of textures in one of the viewer instances, usually the texture
> > goes white when I delete one viewer instance. If the embedded textures were
> > also compressed, then I also get some GL errors, typically:
> >
> > "Warning: detected OpenGL error 'invalid enumerant' at after
> > RenderBin::draw(..)"
> >
> > To be honest, I'm not surprised that this sharing of scene graph data
> > between osg Viewer instances causes a problem. In fact, I’m surprised that
> > more things don’t break. However, the reason this scenario crops up is that
> > my osg viewer is running inside a web based plugin, and hence I get an osg
> > viewer instance within each instance of the plugin that the web browser
> > creates. You might now be wondering why the browser plugin instances
> > share any scene graph data, and in fact I was a bit surprised that they
> > were. I didn’t want them to share data! It turns out that the reason the
> > browser plugin instances share data is because of the cache provided by the
> > osg Registry singleton. It would have been nice if each browser plugin
> > instance ended up with their own osg Registry singleton, but they don’t!
> > (I don’t really want to get on my hobby horse about all the pains that the
> > singleton pattern can cause, but this is certainly one to add to my list)
> >
> > So, my questions boil down to :
> > If viewer instance 1 caches “cow.ive” in Registry singleton, how do I
> > prevent viewer instance 2 from using it?
> > If it does use the cached version, why does cause a problem (seemingly only
> > with textures that were embedded in IVE)?
> > Is there a way to “tweak” the IVE embedded textures so they can be shared
> > successfully in this scenario?
> >
> > I have reduced the problem down to a simple example (20 lines or so) that
> > exhibits the same symptoms:
> >
> >
> > Code:
> > static osg::ref_ptr<osg::Node> model = NULL;
> >
> > class ViewerThread : public OpenThreads::Thread
> > {
> > public:
> > ViewerThread(int x, int y) : x(x), y(y) { }
> > void run()
> > {
> > osgViewer::Viewer viewer;
> > viewer.setUpViewInWindow(x, y, 400, 300);
> > viewer.setSceneData(model);
> > viewer.run();
> > }
> > int x, y;
> > };
> >
> > int main(int argc, char* argv[])
> > {
> > model = osgDB::readNodeFile("cow.ive");
> >
> > ViewerThread* thread1 = new ViewerThread(100, 100);
> > thread1->start();
> >
> > ViewerThread* thread2 = new ViewerThread(500, 100);
> > thread2->start();
> >
> > while(true);
> >
> > return 0;
> > }
> >
> >
> >
> > Chris Denham
> >
> > ------------------
> > Read this topic online here:
> > http://forum.openscenegraph.org/viewtopic.php?p=44810#44810
> >
> >
> >
> >
> >
> > _______________________________________________
> > osg-users mailing list
> >
> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> >
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