Re: [Flightgear-users] Scene graph
On Mittwoch 30 November 2005 05:41, [EMAIL PROTECTED] wrote: 3. Code optimization is the hardest, Talking completely out of my butt here . . .but I remember Matthias Froelich's plib changes that bought us a lot of performance in this regard; that certainly suggests that there may still be ground to be gained that way. There is. I already know something which would help further. But I also remember some discussion in -devel that a better route may be to switch to OpenSceneGraph from plib's SSG. I don't doubt that that's a very non-trivial route to go. I guess I'm just wondering what the people who actually know something about OpenGL coding see as our possible courses in this regard for the future . . . Yes, this is indeed the reason I do not just start implementing further improovements in ssg. I also believe that we could benefit from OpenSceneGraph (from now called shorter osg), but this is also a huge thing which would require some well thought steps. Several steps must be done before we can think about - I know that the ac3d loader is very slow. That would require some prework. We should also double check the other loaders we will use much. - We would need a loader for the flightgear scenery. Not too hard, but somebody needs to do. - We should get rid of further scenegraph dependencies like the sgVec* stuff. For that step I already have something prepared on my local disc which would: Interface well with ssg, interface well with osg and is more intuitive to use than the sg* stuff. - Factor out an own very thin layer which hides acces to the scenegraph. Propably with typedefs or small inlined proxy classes. - Switch that layer to osg and start thinking if it might be beneficial to keep that layer or better remove again it past that step. I believe that this could be done without disturbing other development too much. But I also believe that this is not a one man job. And excuse me for bringing up this on flightgear-users, it just fits that thread even if it should better happen on -devel :) Greetings Mathias -- Mathias Fröhlich, email: [EMAIL PROTECTED] ___ Flightgear-users mailing list Flightgear-users@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-users] scene graph
--- Hemalatha Sharma wrote: Hi, I am using flightgear-0.9.4. Any particular reason why you are using 0.9.4 ? The following comments apply to 0.9.8 and 0.9.9, so I don't know if they work with 0.9.4. I am having 3 views, center view(pilot view), rigth view ,left view.At present i am getting frame rate less than 20 fps, due to this there is no smooth movement on flight.To increase the frame rate i thougth of splitting the process - preparing the scene graph - culling and rendering . because preparing the scenegraph is common for all three.so scenegraph preparation is done in only one system(a seperate pc) and it can send the scene graph structure(thru ethernet) to remaining 3 systems where rendering will be done in individual systems. I doubt it would be fast enough (but I don't know). The general approach people use for multiple views is to have a single computer running the FDM (and possibly one view), then outputting the FDM/state information to other slave machines for the other views over a socket. FG is already set up for this. Have a look at README.IO for details - the native interface is the one you want I think. Instead of splitting up the rendering, it just off-loads the rendering entirely to each machine. Hope this helps. Regards, Stuart ___ Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail http://uk.messenger.yahoo.com ___ Flightgear-users mailing list Flightgear-users@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-users] Scene graph
Hemalatha Sharma wrote: Hi, Thanks for U reply. I have come to know that it is not possible to send entire data of the scene graph. we have thought of one more thing Can we send the frustums data (Data for current frame)to other pc's. But the problem is how to identify that the current data for the particular view (center view ,left,or right). Plz suggest me some ideas regarding this or how to increase the frame rate. There are three primary ways I can think of right now to increase frame rates. 1. Buy faster hardware. 2. Draw a simpler, smaller scene. 3. Optimize the code. I realize there is probably a bit of a language barrier here, but I don't really understand your proposal for improving frame rates (or how the things you mention might apply to improving frame rates.) 1. Is probably the most effective solution, but may not be possible for everyone. 2. In flight gear it's really easy to lower the visibility, or choose to fly in a flatter simpler area. 3. Code optimization is the hardest, and in all honesty, I think you are barking up the wrong tree here with trying to divide up the rendering, but I'm not a computer graphics guru, I tend to stick to the simpler stuff that I can understand. Regards, Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-users mailing list Flightgear-users@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-users] Scene graph
3. Code optimization is the hardest, Talking completely out of my butt here . . .but I remember Matthias Froelich's plib changes that bought us a lot of performance in this regard; that certainly suggests that there may still be ground to be gained that way. But I also remember some discussion in -devel that a better route may be to switch to OpenSceneGraph from plib's SSG. I don't doubt that that's a very non-trivial route to go. I guess I'm just wondering what the people who actually know something about OpenGL coding see as our possible courses in this regard for the future . . . -c ___ Flightgear-users mailing list Flightgear-users@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-users] scene graph
Hi, On Dienstag 29 November 2005 17:57, Curtis L. Olson wrote: I am using flightgear-0.9.4. I am having 3 views, center view(pilot view), rigth view ,left view.At present i am getting frame rate less than 20 fps, due to this there is no smooth movement on flight.To increase the frame rate i thougth of splitting the process - preparing the scene graph - culling and rendering . because preparing the scenegraph is common for all three.so scenegraph preparation is done in only one system(a seperate pc) and it can send the scene graph structure(thru ethernet) to remaining 3 systems where rendering will be done in individual systems. please give ur views ,i want to know whether this one can be implemented. It might be easier to port FG to a scene graph that supports this sort of task division rather than trying to add it to plib's scene graph (which is what flightgear uses.) I doubt there would be advantages to sending the culled scene graph across the network. I suspect the size of the structures would just be too big to do this efficiently. Look into the docs to OpenScenegGraph. There is somebody thinking about piplined rendering on SMP machines together with the Producer which seems the way to go if you would do something like that. OpenSceneGraph as well as the Produces is prepared to do such things. Also if you still need to transfer parts or the whole scenegraph over a network socket, openscenegraph already has a solution ... Greetings Mathias -- Mathias Fröhlich, email: [EMAIL PROTECTED] ___ Flightgear-users mailing list Flightgear-users@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
