Ricky, AFAIK, OSG doesn't maintain VBO/EBO bindings as part of its sortable state. So I believe they will be bound and unbound for each Geometry, even if they are shared. Somebody correct me if I'm wrong. (See Geometry::drawImplementation.)
Glenn Waldron / Pelican Mapping / @glennwaldron On Thu, May 5, 2011 at 11:40 AM, Riccardo Corsi <[email protected]>wrote: > Hi All, > > I revamp this thread as my question is strictly related, as I'm trying to > pack multiple geometries into shared VBO. > > I'm creating a shared osg::Vec3Array for vertices, > same for as many vertex attribute as I need, > and then assigning these shared arrays to the different geometries > (pGeom->setVertexArray() and pGeom->setVertexAttribArray() ) > and telling the geometry to use VBO and not display lists. > > Then I create a new DrawElements for each geometry, with the correct vertex > indices offset, > and as I want them to share the same EBO underneath, > I'm trying with: > pDrawElemsUInt->setElementBufferObject(pSharedEBO); > pGeom->addPrimitiveSet(pDrawElemsUInt); > > But I think I' missing something because, with gDebugger, I see that there > are as many bindBuffer calls as num-geom * num-shared-buffers. > > Am I wrong in the way I try to share the drawElems EBO? Or missing > something else? > Thank you! > > Ricky > > > > > On Mon, Jan 3, 2011 at 19:31, Jason Beverage <[email protected]>wrote: > >> Hi Terry, >> >> I was generating all my geometry in code so I wrote some custom code >> to pack them tightly into a single vertex array. >> >> Jason >> >> On Mon, Jan 3, 2011 at 1:05 PM, Terry Welsh <[email protected]> wrote: >> > Hi Jason, >> > Thank you for the suggestion. I feel like I'm missing something >> > still. Is there an Optimizer feature or something that combines >> > Arrays for you? Or did you write a bunch of custom code that >> > processes your models after you load them? >> > -- >> > Terry Welsh >> > mogumbo 'at' gmail.com >> > www.reallyslick.com >> > >> > >> > >> >> Message: 3 >> >> Date: Sun, 2 Jan 2011 21:28:12 -0500 >> >> From: Jason Beverage <[email protected]> >> >> To: OpenSceneGraph Users <[email protected]> >> >> Subject: Re: [osg-users] large VBOs for multiple Drawables >> >> Message-ID: >> >> <[email protected]> >> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> >> >> Hi Terry, >> >> >> >> You can pack the verts of your small objects into a single >> >> osg::Vec3Array and share that array across multiple osg::Geometry >> >> objects then use DrawElements for each geometry with the correct >> >> indices. I've just recently done this actually for a project I'm >> >> working on and it's worked out great. >> >> >> >> Thanks, >> >> >> >> Jason >> >> >> >> On Sat, Jan 1, 2011 at 6:21 PM, Terry Welsh <[email protected]> wrote: >> >>> I found some email threads that hinted at this a little, but nothing >> >>> seemed very specific. ?I have scenes where display lists perform a bit >> >>> better than VBOs. ?My best guess is because my objects have relatively >> >>> small vertex counts (usually between 20 and 200). ?Is there any way in >> >>> OSG to use one large VBO to store the date for multiple Drawables in >> >>> order to minimize buffer state changes? >> >>> -- >> >>> Terry Welsh >> >>> mogumbo 'at' gmail.com >> >>> www.reallyslick.com >> >>> _______________________________________________ >> >>> osg-users mailing list >> >>> [email protected] >> >>> >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > _______________________________________________ >> > osg-users mailing list >> > [email protected] >> > >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >
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