Thanks for pointing that out... I keep forgetting to fix my reply in plain text... Now this would explain why Robert did not respond... and all this time I thought it was because I made him upset. ;)
On a side note... I really really really... hope that the client code will not have to break up the rendering into subsections like suggested in the threaded building blocks document from intel. ----- Original Message ----- From: Cedric Pinson To: OpenSceneGraph Users Sent: Thursday, June 26, 2008 4:33 PM Subject: Re: [osg-users] multi threaded with slave camera and fbo Your mails are black so i need to select the test to read it. Anyway i am interested by all result you have. If you can post them Cedric James Killian wrote: > > I too find some interesting issues with this thread. :) > > Robert, > This proposal you mention for 2.6 will it help balance the cpu > workload against the gpu I/O bottleneck? > > I've been doing some osg performance benchmark research on thread > synchronization using the Intel Threaded compiler, and so far the > results are looking really good except for a 26% over-utilization due > to sleeping. I do want to say awesome job to those responsible for > threading, the amount of critical section use looked very good! All > the worker threads also had good profiling results. > > The ultimate test I want to try today deals with an intentional GPU > bottleneck... where I have a quadcore that pipes graphics out a PCI > graphics card. If anyone is interested I'll post these test results. > I know now that using a quad core there is lack of parallelization > (e.g. 25% 85% 15% 15%), but that is a different battle for a different > time. > > I do want to get to the bottom of the profiling and determine how well > the workload is balanced against the gpu i/o, and see if there is some > opportunity for optimization here. > > > > ----- Original Message ----- > *From:* Robert Osfield <mailto:[EMAIL PROTECTED]> > *To:* OpenSceneGraph Users > <mailto:[email protected]> > *Sent:* Thursday, June 26, 2008 7:06 AM > *Subject:* Re: [osg-users] multi threaded with slave camera and fbo > > Hi Guys, > > I've just skimmed through this thread. Interesting issues :-) > > Wojtek explanations of the double buffered SceneView is spot on, in > this case leading to two FBO's, Creation of two FBO's for RTT is > something I've been aware of since the inception of the > DrawThreadPerContext/CullThreadPerCameraDrawThreadPerContext, but as > yet haven't had the opportunity to refactor the code to avoid it. > > The problem actually stems from the reuse of SceneView to do something > that it was never intended to handle, and in terms of osgViewer > implementation SceneView was used simply because it was the line of > least resistance i.e. it worked and code be adapted to help speed up > the implementation of osgViewer, and mostly it's actually worked out > ok, the stop gap has worked out pretty well. > > However, it has always been my plan to rewrite the osgViewer::Renderer > so that it doesn't use SceneView at all, let alone double buffering > them, instead it's my plan to use a single CullVisitor which > alternately populates double buffered RenderStage. This approach > would be far leaner and less obfusticated, and we should be able to > clean up some of the artefacts as well. The downside is by not using > SceneView we'll loose all the stereo rendering support, so instead > we'll need to refactor osgViewer so that stereo rendering is done at > the viewer level i.e. using slave cameras - this means more coding > work, but the actually end result would be far better both design wise > as well as in flexibility and performance. > > I just need to time to go off and do this work, I might be able to get > it done for 2.6, but spare time certainly isn't something that I'm > blessed with right now. > > Robert. > _______________________________________________ > osg-users mailing list > [email protected] > <mailto:[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 > -- +33 (0) 6 63 20 03 56 Cedric Pinson mailto:[EMAIL PROTECTED] http://www.plopbyte.net _______________________________________________ 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
