After looking at this, I wonder if we can still do the optimization, but do it in the Face class destructor instead of readRecord() (and similarly for Mesh). I'd like Brede's input on this before diving in and changing the code. -Paul
> Hi Paul and Brede, > > I'm posting this email so you guys know that I just applied a > fix to a premature optimization that had been done in the > OpenFlight plugin. > Paul you might want to apply this to the OpenSceneGraph-2.6 branch. > The SVN revision is 9041. > > http://www.openscenegraph.org/projects/osg/changeset/9041 > > The change is to simply remove the "simple share stateset > optimization by adding an #if 0, #endif block to > GeometryRecords.cpp as below: > > #if 0 > // note from Robert Osfield, this "optimization" breaks > multi-textured datasets that mix single texture // and > mulit-texture geometries as the Multitexture parsing can come > after the below code, and accidentally // polute the non > multi-texture geometries StateSet. > > // A simple share stateset optimization. > static osg::ref_ptr<osg::StateSet> lastStateset; > if (lastStateset.valid() && > (stateset->compare(*lastStateset,false)==0)) > stateset = lastStateset; > else > lastStateset = stateset; > #endif > > > The problem itself appeared when a OpenFlight model had > geometries that had both single and multi-texturing > geometries in them, where the first texture unit's texture > was the same between the single texture coord geometry and > the multi-texture geometry, this resulted in the the above > optimizing concluding that the StateSet's could be shared, > but this optimization was being done prior the > MultiTextureRecord was being parsed, and when it was parsed > it applied its second texture to shared instance - hence > poluting the single texture coord geometry with a second > texture. The visible results of this was random flickering > on of colours. > > I haven't removed the above code, but it probably should be > removed completely as I can't see a way for the optimization > to be able to be done in GeometryRecords.cpp as the not > enough info is known at this point. I've left the code in > right now to make clear what's been changed and why. > > Robert. > _______________________________________________ > osg-submissions mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-o penscenegraph.org > _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
