Re: [osg-users] Need advice for performance tweaks
Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC wrote: Robert, Thanks for the quick reply. I haven't played with the LOD scale so I'll explore that. I also like your suggestion of some sort of adaptive setting. Is there a way to query the frame time of the previous frame? Look at the statistics (S key) feature of osgViewer and see how it does it. Thanks, -Shayne -- Chris 'Xenon' Hanson, omo sanza lettere Xenon AlphaPixel.com PixelSense Landsat processing now available! http://www.alphapixel.com/demos/ There is no Truth. There is only Perception. To Perceive is to Exist. - Xen ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Need advice for performance tweaks
All, I have a need to run my OSG app on some marginal hardware (single CPU with a GeForce 4800 for example) while still maintaining some decent frame rates (around 30fps). I want to use the same terrain database (built with VPB with the -terrain option) if possible. I've used the setSampleRatio() method in the osgTerrain class and culling backfaces to thin out the geometry with some success but I'm still not where I need to be. As a result, I'm wanting to optimize a bit more if possible. Does anyone have any suggestions for particular settings in the databasepager or pagedLOD that I could try to achieve better performance? I'm willing to sacrifice database fidelity to maintain decent frame rates if I must. Thanks for any suggestions in advance. Shayne smime.p7s Description: S/MIME cryptographic signature ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Need advice for performance tweaks
Hi Shayne, You can use the osgTerrain::Terrain::setSampleRatio(float) to cut down geometry complexity alone, and use osg::Camera::setLODScale(float) to make the selection of LOD's more aggressive. One thing you could do is implement an adaptive setting of LODScale/SampleRatio by looking at the frame time of the previous frame and it is looks close to breaking frame change the ratio's to reduce the overhead, this way you might be able to get away with better visuals when the hardware can cope such as looking downwards, and only go for low high res visuals when you are looking at a shallow angle to the horizontal when lots of tiles will be in view. Robert. On Fri, Nov 27, 2009 at 6:00 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: All, I have a need to run my OSG app on some marginal hardware (single CPU with a GeForce 4800 for example) while still maintaining some decent frame rates (around 30fps). I want to use the same terrain database (built with VPB with the -terrain option) if possible. I've used the setSampleRatio() method in the osgTerrain class and culling backfaces to thin out the geometry with some success but I'm still not where I need to be. As a result, I'm wanting to optimize a bit more if possible. Does anyone have any suggestions for particular settings in the databasepager or pagedLOD that I could try to achieve better performance? I'm willing to sacrifice database fidelity to maintain decent frame rates if I must. Thanks for any suggestions in advance. Shayne ___ 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
Re: [osg-users] Need advice for performance tweaks
Robert, Thanks for the quick reply. I haven't played with the LOD scale so I'll explore that. I also like your suggestion of some sort of adaptive setting. Is there a way to query the frame time of the previous frame? Thanks, -Shayne -Original Message- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield Sent: Friday, November 27, 2009 11:08 AM To: OpenSceneGraph Users Subject: Re: [osg-users] Need advice for performance tweaks Hi Shayne, You can use the osgTerrain::Terrain::setSampleRatio(float) to cut down geometry complexity alone, and use osg::Camera::setLODScale(float) to make the selection of LOD's more aggressive. One thing you could do is implement an adaptive setting of LODScale/SampleRatio by looking at the frame time of the previous frame and it is looks close to breaking frame change the ratio's to reduce the overhead, this way you might be able to get away with better visuals when the hardware can cope such as looking downwards, and only go for low high res visuals when you are looking at a shallow angle to the horizontal when lots of tiles will be in view. Robert. On Fri, Nov 27, 2009 at 6:00 PM, Tueller, Shayne R Civ USAF AFMC 519 SMXS/MXDEC shayne.tuel...@hill.af.mil wrote: All, I have a need to run my OSG app on some marginal hardware (single CPU with a GeForce 4800 for example) while still maintaining some decent frame rates (around 30fps). I want to use the same terrain database (built with VPB with the -terrain option) if possible. I've used the setSampleRatio() method in the osgTerrain class and culling backfaces to thin out the geometry with some success but I'm still not where I need to be. As a result, I'm wanting to optimize a bit more if possible. Does anyone have any suggestions for particular settings in the databasepager or pagedLOD that I could try to achieve better performance? I'm willing to sacrifice database fidelity to maintain decent frame rates if I must. Thanks for any suggestions in advance. Shayne ___ 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 smime.p7s Description: S/MIME cryptographic signature ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
