HI Guys, What are you all doing with your RTT Camera's? Are you just doing render to texture, or are you doing a copy to Image/glReadPixels as well? The later will throw a big slow down as it requires a round trip to the graphics card and an associated finish of the all OpenGL prior to the glReadPixels.
Robert. On Fri, Sep 5, 2008 at 6:38 PM, Harash Sharma <[EMAIL PROTECTED]> wrote: > Hi Steffen, Guay and Robert, > > In the same regard I would like to mention something. We have also > developed an application that uses multiple RTT cameras. However only one > camera is active at a time ( the rest are masked using node mask). All > cameras differ only in the resolution of the texture, they are viewing > exactly the same scene and have identical fields of view. We too have found > that the frame rate has a lot of dependence on the texture size. 256 x256 > texture gives a fairly high frame rate(30+ frames/second), 512x512 slows it > down considerably (to around 8 frames / second) and 1024x1024 slows it even > further (~ 1 fps). All these figures are in release mode build. > > My machine specifications > Processor: Xeon 5160 > RAM: 4 GB Fully Buffered DDR2 > Graphics: nVidia Quadro FX4500 (512MB) > > I would be highly obliged if a way out can be suggested. > > Regards > > Harash > ----- Original Message ---- > From: Steffen Kim <[EMAIL PROTECTED]> > To: osg-users@lists.openscenegraph.org > Sent: Friday, September 5, 2008 10:04:25 PM > Subject: Re: [osg-users] performance issues with RTT > > Thanks for the hints so far... > > I gave you wrong information since I forgot that I take care of the > NPOT-stuff myself. > The API I use later on needs POT-textures so I make sure that only > POT-textures are rendered. So in fact my textures are normally 2048x1024. > > I know that the performance issues are most certain a problem of the texture > rendering since we have parts of the application where even huger amounts of > (normal render-to-view) cameras are involved without slowing down everything > as much. The scene is pretty simple too and runs smoothly without the > RTT-cameras. > Back on Monday I will try to get some FPS-values for exactly the same > camera-setup with and without RTT for different scene complexities (here in > Germany the weekend begins now ;)). > > What I just found out is that the texture sizes make a huge difference in > rendering performance. With 256x256-textures my cameras hardly slow down the > viewer at all. That's also an evidence that the problem has to be somewhere > in the texture-creation-part. > If this cannot be enhanced then I probably have to find a good balance > between quality and speed. > But I still have hopes that there are better ways to improve my performance > without having to sacrifice too much resolution-wise. > > BTW: I'm running my stuff on a Xeon 5160 at 3GHz and 2GB RAM with a Radeon > X1900 card. > > Have a nice weekend, > Steffen > > > > _______________________________________________________________________ > Jetzt neu! Schützen Sie Ihren PC mit McAfee und WEB.DE. 30 Tage > kostenlos testen. http://www.pc-sicherheit.web.de/startseite/?mc=022220 > > _______________________________________________ > 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 > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
