Re: [osg-users] left/right alternating stereo
Hi, I have a NVidia Quadro video card and I have resolved using Quad Buffer after configuring NVidia Control Panel correctly for stereo visualization. Thank you! Cheers, Francesco Francesco Argese -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=62456#62456 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] left/right alternating stereo
Hi Guys, I haven't ever worked with alternating stereo - all my work has been with side-by-side, quad buffer and HMD's. There is chance that the driver+graphics hardware might support alternating stereo, I'd expect something like you app sets up quad buffer stereo and the hardware coordinates sending the appropriate left/right buffer out. The spanner in the works is that NVidia has restricted quad buffer stereo support to their Quadro line. Perhaps others will have experience on this side. Another approach, and entirely OSG side one, would be to set up the stereo using an osgViewer slave Camera configuration where you have a left and right slave Camera that share the same graphics context, viewport and subgraph but have their NodeMask toggled on/off on alternate frames so there is only one Camera actually drawing to the current frame. The next bit is the awkward part - you need to sync the frame rate to 120hz and to sync the left/right toggle so that the appropriate Camera is toggled for the correct frame, if you get it wrong then they'd get out sync. You'd need make sure that you app hits 120hz every frame otherwise it'll get out sync. In svn/trunk and OSG-3.2.x there is a osgViewer/config collection to provide examples of different slave Camera configurations, and stereo is set up for them in src/osgViewer/View.cpp, have a look at the assignStereoCamera(..) as this will flesh out how one sets up slave Camera's to do stereo for you. A refinement of the above approach might be to create your own quad buffer style buffer that you render to - i.e. a side by side offscreeen graphics context (pbuffer) with two side-by viewports that is also double buffered in some way, and then have another shared context that reads from the side by by side pbuffer when rendering. The first context would run at it's own frame rate, when the second one that actually renders to the display would be locked at 120hrz. I really don't know if this could be made to work, in effect it'd be replicating quad buffer stereo. The sync with the display is something you'd want to look at, if the video players you've looked are open source then looking the code would be helpful. Robert ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] left/right alternating stereo
Hi Guys, I haven't ever worked with alternating stereo - all my work has been with side-by-side, quad buffer and HMD's. There is chance that the driver+graphics hardware might support alternating stereo, I'd expect something like you app sets up quad buffer stereo and the hardware coordinates sending the appropriate left/right buffer out. The spanner in the works is that NVidia has restricted quad buffer stereo support to their Quadro line. Perhaps others will have experience on this side. I tinkered around for a bit a while ago. Assuming your on Linux Nominally you'd use the 'Xorg.conf' to define which stereo mode you are using when rendering quad buffer output. This is obviously the best method as it offloads the L/R frame switching to the GFX card, and thus doesn't really matter if your application can't keep up. See 'Option Stereo integer' http://us.download.nvidia.com/XFree86/Linux-x86/173.14.12/README/appendix-b.html If you don't have a quad buffer capable card there is a LD_PRELOAD/shim which you might like to try: https://code.google.com/p/stereowrap/ This requires a nice fast computer to actually achieve target frame rate (120Hz for DLP stereo projection). If you are looking to recompile, then you might even linking against 'libgls' which also fakes up the quadbuffer. http://libgls.sourceforge.net/ This lib also includes some signalling code, which uses the first line of display to trigger display to automatically go into 3D mode. Cheers, Simon. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] left/right alternating stereo
Hi, i have the same problem I have a system where graphic board (nvidia K5000) must be setted to 60Hz, and a projector able to go to 120Hz (between graphic card and projector there are 2 devices that work only to 60 Hz). To visualize stereo 3D, this system uses a player like butterfly3D (or BINO, http://bino3d.org/doc/bino.html#Overview-1). It loads a syde-by-syde left-right movie (60 Hz) and sends an alternating left-right (60Hz) to projector. The projector (Vivitek D5380U), receives a 60Hz input signal and visualizes a type of stereo (like quad buffer) at 120Hz. It seems to duplicates the frequency. Using Bino, stereo works (quite correctly). I would like to visualize OSG application in stereo mode (using the same approach), on this system. My question is : If i use quadbuffer stereo forcing frequency to 60 Hz, do i get the same result? This becouse i have no side by side source. So i suppose that with a slow quad buffer, i can simulate the alternating output to projector. Is it possible to force quadbuffer to 60Hz? On a common workstation with nvidia quadro 600, using a 60Hz monitor and use quadbuffer stereo, i see the alternating frames slower than on 120 Hz monitor. This is the reason for forcing the quadbuffer to 60Hz. I try to direct execute quadbuffer on the system with openscenegraph application, but i don't see the alternating images (i get also an error : detect OpenGL error 'invalid operation' at after RenderBin::draw(...). I see a single image (like mono view). Thank you! Cheers, Andrea -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=62389#62389 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] left/right alternating stereo
Hi, does OpenSceneGraph supports left/right alternating stereo as output? I'm working on a system where I need to set this type of stereo because side by side stereo doesn't work on it but I have found working this type of stereo that is available on Bino open source video player. This type of stereo is described at the following link among supported output techniques: http://bino3d.org/doc/bino.html#Output-Techniques Does exist in OpenSceneGraph a similar type of stereo? Thank you! Cheers, Francesco Francesco Argese -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=62373#62373 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
