Re: [osg-users] Multiple viewers and one scene
Thanks a lot for your answer, now I understand a bit of what is going on... I will write the example for better understanding of what I am trying to do and look at the code you suggested. I'll derive it from the code in osgwindows (setting one camera for each window in an independent viewer) and post it here as soon as possible. Just in case you are curious about my case of use, I will try to explain a bit my intentions, if you consider that my approximation is not right please correct me. I am building a simulation framework aimed at multi-robot collaborative perception. I am going to implement this using a composite viewer with at least two views for the simulator user interface, plus a dynamic number of viewers, one for each simulated camera as I need to be able to set the frame rate of the cameras independently. The cameras of these viewers would render to a pbuffer each and have an image attached in order to send then to the artificial vision algorithms. I also need to share the scene across all the viewers. Thanks, Nicolas . 2008/2/24, Robert Osfield [EMAIL PROTECTED]: HI Nicolas, On Fri, Feb 22, 2008 at 7:11 PM, nicolas peña [EMAIL PROTECTED] wrote: I have done several tests and have reached to the conclusion that it is not possible to use two viewers at the same time from one process. Are you running the viewers single threaded? If so then the lazy setting of makeCurrent for each for the viewers will mean that after the first frame the makeCurrent won't be called as the viewer assumes that it already has the context current so can save the cost of the makeCurrent. Interleaving two viewers in the same thread would then cause one viewer's GraphicsWindow to be the one that is current and the other will never be updated. osgViewer hasn't been designed for this usage model - one that I haven't ever thought of as a combination in fact - its support may different combinations of viewer usage but just not this one I'm afraid. Potentially we could modify osgViewer::ViewerBase to allow you to use the viewer in this way i.e. have two viewers called from the same frame loop thread, this would require switching off the lazy makeCurrent mechanism - the method that does it is ViewerBase::makeCurrent(osg::GraphicsContext* gc) that you'll find in include/osgViewer/ViewerBase. Perhaps a bool flag in ViewerBase could be used to enable the lazy makeCurrent() for instance. This happens even when they do not share anything and even if I set-up the viewers from different threads. I have done the most simplistic code and even this fail. I'm using OSG 2.3.4 on Linux 2.6.22 with NVIDIA proprietary drivers. I would like to help to solve this if you confirm it as a bug and if it is possible. You usage model is rather unusually so you using osgViewer out of scope, so rather than bugs its most design limitations. The OSG is not a static object - it evolves over time in response to being pushed into new spheres and usage models, this sometimes requires big refactoring to open the news ways of using it, but often a little tweak here or there can deliver a lot. I haven't fully got my head around your usage model, so I'd suggest writing an example that could go in OpenSceneGraph/examples that illustrates what you are trying to do, but its failing. This example could then be used by others to see the problem first hand and then a solution could be found, but it a tweak to the example or a tweak to osgViewer itself. Robert. ___ 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] Multiple viewers and one scene
On Mon, Feb 25, 2008 at 8:49 AM, nicolas peña [EMAIL PROTECTED] wrote: Just in case you are curious about my case of use, I will try to explain a bit my intentions, if you consider that my approximation is not right please correct me. I am building a simulation framework aimed at multi-robot collaborative perception. I am going to implement this using a composite viewer with at least two views for the simulator user interface, plus a dynamic number of viewers, one for each simulated camera as I need to be able to set the frame rate of the cameras independently. The cameras of these viewers would render to a pbuffer each and have an image attached in order to send then to the artificial vision algorithms. I also need to share the scene across all the viewers. My guess is that this should probably be possible given separate threads for each of the viewers frame loops i.e. run them all in a background thread. Sharing of images is possible by using a frame buffer copy to osg::Image, or just having multiple FBO's all within one graphics context. If you can have the frames all done synchronously then perhaps you could have one frame loop and just disable the cameras that you don't need updating on each frame, i.e. main viewer runs at 60Hz, and the other RTT cameras run at 20Hrz so get update on frame in 3. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Multiple viewers and one scene
On Mon, Feb 25, 2008 at 9:22 AM, nicolas peña [EMAIL PROTECTED] wrote: Yes, I think I'll be OK with that. Sorry for my lack of knowledge but, can you tell me how can I deactivate/activate the cameras ?. I don't find the proper method. camera-setNodeMask(0x0); ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Multiple viewers and one scene
I'll work with this. Thanks a lot. Nicolas. 2008/2/25, Robert Osfield [EMAIL PROTECTED]: On Mon, Feb 25, 2008 at 9:22 AM, nicolas peña [EMAIL PROTECTED] wrote: Yes, I think I'll be OK with that. Sorry for my lack of knowledge but, can you tell me how can I deactivate/activate the cameras ?. I don't find the proper method. camera-setNodeMask(0x0); ___ 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] Multiple viewers and one scene
HI Nicolas, On Fri, Feb 22, 2008 at 7:11 PM, nicolas peña [EMAIL PROTECTED] wrote: I have done several tests and have reached to the conclusion that it is not possible to use two viewers at the same time from one process. Are you running the viewers single threaded? If so then the lazy setting of makeCurrent for each for the viewers will mean that after the first frame the makeCurrent won't be called as the viewer assumes that it already has the context current so can save the cost of the makeCurrent. Interleaving two viewers in the same thread would then cause one viewer's GraphicsWindow to be the one that is current and the other will never be updated. osgViewer hasn't been designed for this usage model - one that I haven't ever thought of as a combination in fact - its support may different combinations of viewer usage but just not this one I'm afraid. Potentially we could modify osgViewer::ViewerBase to allow you to use the viewer in this way i.e. have two viewers called from the same frame loop thread, this would require switching off the lazy makeCurrent mechanism - the method that does it is ViewerBase::makeCurrent(osg::GraphicsContext* gc) that you'll find in include/osgViewer/ViewerBase. Perhaps a bool flag in ViewerBase could be used to enable the lazy makeCurrent() for instance. This happens even when they do not share anything and even if I set-up the viewers from different threads. I have done the most simplistic code and even this fail. I'm using OSG 2.3.4 on Linux 2.6.22 with NVIDIA proprietary drivers. I would like to help to solve this if you confirm it as a bug and if it is possible. You usage model is rather unusually so you using osgViewer out of scope, so rather than bugs its most design limitations. The OSG is not a static object - it evolves over time in response to being pushed into new spheres and usage models, this sometimes requires big refactoring to open the news ways of using it, but often a little tweak here or there can deliver a lot. I haven't fully got my head around your usage model, so I'd suggest writing an example that could go in OpenSceneGraph/examples that illustrates what you are trying to do, but its failing. This example could then be used by others to see the problem first hand and then a solution could be found, but it a tweak to the example or a tweak to osgViewer itself. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Multiple viewers and one scene
I forgot to say that I was two instances of osgviewer::viewer. Thanks again, Nicolas. 2008/2/22, nicolas peña [EMAIL PROTECTED]: Hi Robert, I have done several tests and have reached to the conclusion that it is not possible to use two viewers at the same time from one process. This happens even when they do not share anything and even if I set-up the viewers from different threads. I have done the most simplistic code and even this fail. I'm using OSG 2.3.4 on Linux 2.6.22 with NVIDIA proprietary drivers. I would like to help to solve this if you confirm it as a bug and if it is possible. Thanks a lot, Nicolas. 2008/2/22, Robert Osfield [EMAIL PROTECTED]: Hi Nicolas, Its really hard to know whats going on at your end w.r.t application setup and flow control so advicing on it is easy. In general I can say that sharing a scene between View's is OK within on CompositeViewer as they will Views on the same scene will share the same FrameStamp i.e. there will be all at the same point in time. Sharing one scene between multiple Viewers will hit up against the problem that in one set of traversals the scene graph is one time and then the traversals from the other viewer will try to change the time back - and likely to cause a mess. This timing issue isn't likely to cause problems with high level rendering though - it should just mess up things like particle systems and sequences. Robert. On Thu, Feb 21, 2008 at 8:33 PM, nicolas peña [EMAIL PROTECTED] wrote: Hi all, As I need to control the frame rate of my cameras independently, I have set-up a viewer for each one. One camera has to draw in a window and accept user input, while the others should not appear in the screen at all (they have an image attached and send a copy of it to other process). To achieve this, the interactive camera's graphic context is set from a traits with pbuffer = false and the other one with pbuffer = true. The problem is that if a set up a loop that calls the frame method of both one renders over the other as if the rendering contexts were the same. Can I share the scene among different viewers? If yes what do I need to do to render properly? Please ask for the needed details... Thanks a lot, Nicolas. ___ 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
Re: [osg-users] Multiple viewers and one scene
Hi Robert, I have done several tests and have reached to the conclusion that it is not possible to use two viewers at the same time from one process. This happens even when they do not share anything and even if I set-up the viewers from different threads. I have done the most simplistic code and even this fail. I'm using OSG 2.3.4 on Linux 2.6.22 with NVIDIA proprietary drivers. I would like to help to solve this if you confirm it as a bug and if it is possible. Thanks a lot, Nicolas. 2008/2/22, Robert Osfield [EMAIL PROTECTED]: Hi Nicolas, Its really hard to know whats going on at your end w.r.t application setup and flow control so advicing on it is easy. In general I can say that sharing a scene between View's is OK within on CompositeViewer as they will Views on the same scene will share the same FrameStamp i.e. there will be all at the same point in time. Sharing one scene between multiple Viewers will hit up against the problem that in one set of traversals the scene graph is one time and then the traversals from the other viewer will try to change the time back - and likely to cause a mess. This timing issue isn't likely to cause problems with high level rendering though - it should just mess up things like particle systems and sequences. Robert. On Thu, Feb 21, 2008 at 8:33 PM, nicolas peña [EMAIL PROTECTED] wrote: Hi all, As I need to control the frame rate of my cameras independently, I have set-up a viewer for each one. One camera has to draw in a window and accept user input, while the others should not appear in the screen at all (they have an image attached and send a copy of it to other process). To achieve this, the interactive camera's graphic context is set from a traits with pbuffer = false and the other one with pbuffer = true. The problem is that if a set up a loop that calls the frame method of both one renders over the other as if the rendering contexts were the same. Can I share the scene among different viewers? If yes what do I need to do to render properly? Please ask for the needed details... Thanks a lot, Nicolas. ___ 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
