Hi Andrew, I wouldn't recommend creating a single osg::Geometry with millions of vertices/primitives, while in theory it should work, even if it does it's likely to perform poorly as the GL driver won't be able to just render the data directly - it'll need to stream it in chunks.
To get big datasets working efficiently it's best to break them up into chunks of tens of thousands of points and to use VBO's. This way the OpenGL data can pass the data in blocks of a size that are much more amenable to being downloaded directly to the graphics hardware. The src/osgPlugins/3dc plugin can handle tens of millions of points with decent performance, and achieve this by doing the chunking of the data I suggest above, so have a look at it's source for inspiration. Robert. On Thu, Dec 23, 2010 at 7:57 PM, Andrew Cunningham <andr...@mac.com> wrote: > Hi, > I have a Quadro FX 1700 with the latest 64-bit Nvidia drivers on Windows > XP/64. My app is a 64-bit Windows application. > > For testing I am creating a single osg::geometry with probably about 3.2 > million QUAD primitives , using > quadPrims_=new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS); > > I am not using VBO's. > > Once the osg scene graph is created, and the render phase begins. I see the > border of my screen "flash" black twice and then my application is in "la-la" > land, with a blank 3D window and needs to be killed. The app is using about > 2G of memory but I have 9G free. > > > More info... > - osg does not report any errors > > - if I turn off the nVidia driver and switch to the default "software" OpenGL > driver, the geometry renders fine. > > - If I take a geometry of a similar size or even much bigger, but break it up > into multiple geometries so that each DrawElementsUInt is "smaller" there are > no problems. > > I am not aware of any specific limitations on glDrawElements that says the > number of elements must be < "some number". The reference guide says there > may be performance problems with numbers > GL_MAX_ELEMENTS_VERTICES/INDICES > but it is not a hard limit. > > Any one experienced similar problems? > > Andrew > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=35136#35136 > > > > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
