Re: [osg-users] OSG and HMD
Thanks all for the replies. So what would you do: A: use OSG and add advanced graphics features to improve picture quality? B: use prof. engine that already supports HMD and try to minimize latency? I really like to read your opinions on this! -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=55728#55728 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] OSG and HMD
Hi CJ, We've been using OSG with either CAVELib or Mike Weiblen's osgVRPN with Will Hollingsworth's additions: https://github.com/VirtualMe/osgvrpn/tree/master/trunk We've tested it with an old serial Flock of Birds, and a couple Intersense devices, including one mounted to an iGlasses HMD. I still haven't checked out a Rift, but latency isn't an issue with our simple scenes. CJ wrote: > Hi, > > I'm looking for a graphics engine for a flight simulator using a HMD like the > Oculus Rift. > Because of the HMD I need a very low latency. But I also would like very high > graphics quality. > > Which of the following two approaches would be best? > A. > Use some high quality game engine and switching off all features that result > in high latency. Thus lowering the latency. I do not know if there will still > be high enough quality graphics left. > B. > Use OSG and add features for higher quality graphics witout adding to much > latency. I do not know if that is doable. > > I think the big advantage of B (using OSG) is that I have full controll of > the rendering. So low latency may be easier to get. But how difficult wil it > be to add features to get high quality graphics? > > I hope you guys can give some usefull comments on this. > Thank you! > > Cor -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=55743#55743 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] OSG and HMD
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hello Robert, Cor On 08/02/2013 12:00 PM, Robert Osfield wrote: > Hi Cor, > ... > > W.r.t latency you'll need to avoid SLI/Multicard altenate frame > rending by the driver if you are using two cards as this will screw > up latency big time. You will also want to avoid stuffing too > many frames down to the grpahics card so use of sync barrier might > be appropriate. In immerisve work you'll want low latency and > also constist frame rate, this trumps visual effects as if you > compromise either of these the user will loose their feeling of > immerision and likely feel sick. Actually, one *has to* use sync barrier (vsync) with Oculus Rift - don't even think to work without. The display cannot do more than 60Hz anyway, so the extra frames are wasted time, but what is worse, the tearing gets massively magnified by the lenses and is extremely disturbing, because it is constantly right in front of your eyes. The low latency on the Rift is important, but there is no need to go overboard - as I said, the display is limited to 60Hz and is quite slow, so you will get smearing/motion blur with fast movements anyway. Any reasonable 3D engine should be able to hit 60fps with ease if you keep your geometry load sane and use graphic card that is up to the task (i.e. not some integrated low end one). Another trick that helps a lot with image quality in the Rift is anti-aliasing - at least 4x helps a lot to mitigate the infamous "screen-door" effect (visible pixel raster of the display). Re: > > Which of the following two approaches would be best? A. Use some > high quality game engine and switching off all features that result > in high latency. Thus lowering the latency. I do not know if there > will still be high enough quality graphics left. In fact, you will have major difficulties adapting a random game engine to support the Rift unless it is supported by the game engine vendor already (Unity Pro or Unreal) and/or you have the source code. The Rift requires rather special rendering code (off-screen rendering with pre-distortion), that may not be straightforward to integrate. If you want to use OSG with the Rift, there is an example here: https://github.com/bjornblissing/osgoculusviewer Regards, Jan -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iD8DBQFR+6D7n11XseNj94gRAuc9AKCsLGn45svMi0X8dqKblBatojDKEgCfYSTZ Od9/+Iib2XBXzEM7tu3QmOY= =Fuaz -END PGP SIGNATURE- ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] OSG and HMD
Hi Cor, The OSG is better engineered for muli-threaded multi-context work as it's heritage is in vis-sim and VR, so very much the type of use that one would use with a HMD. Members of the community are alreayd experiementing with Oculus Rift support so do some searches to see the latest of this development. As for performance, you really have to cut your cloth to the cloth you have, if you are rendering to two displays that you have twice as much geometry work to do, but if the display is lower res than a typical desktop then pixel load might be lower. There is no reason why you should be able to achieve good graphics quality with modern graphics card on a HMD but you'll just need to balance the complexity of the scene you render to the performance metrics you are after. W.r.t latency you'll need to avoid SLI/Multicard altenate frame rending by the driver if you are using two cards as this will screw up latency big time. You will also want to avoid stuffing too many frames down to the grpahics card so use of sync barrier might be appropriate. In immerisve work you'll want low latency and also constist frame rate, this trumps visual effects as if you compromise either of these the user will loose their feeling of immerision and likely feel sick. Robert. On 15 July 2013 10:46, Cor Jansen wrote: > Hi, > > I'm looking for a graphics engine for a flight simulator using a HMD like the > Oculus Rift. > Because of the HMD I need a very low latency. But I also would like very high > graphics quality. > > Which of the following two approaches would be best? > A. > Use some high quality game engine and switching off all features that result > in high latency. Thus lowering the latency. I do not know if there will still > be high enough quality graphics left. > B. > Use OSG and add features for higher quality graphics witout adding to much > latency. I do not know if that is doable. > > I think the big advantage of B (using OSG) is that I have full controll of > the rendering. So low latency may be easier to get. But how difficult wil it > be to add features to get high quality graphics? > > I hope you guys can give some usefull comments on this. > Thank you! > > Cor > > -- > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=55216#55216 > > > > > > ___ > 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] OSG and HMD
Hi, I'm looking for a graphics engine for a flight simulator using a HMD like the Oculus Rift. Because of the HMD I need a very low latency. But I also would like very high graphics quality. Which of the following two approaches would be best? A. Use some high quality game engine and switching off all features that result in high latency. Thus lowering the latency. I do not know if there will still be high enough quality graphics left. B. Use OSG and add features for higher quality graphics witout adding to much latency. I do not know if that is doable. I think the big advantage of B (using OSG) is that I have full controll of the rendering. So low latency may be easier to get. But how difficult wil it be to add features to get high quality graphics? I hope you guys can give some usefull comments on this. Thank you! Cor -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=55216#55216 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
