Hi Mathias, I'm afraid I have way too much work on my plate to go investigating user applications.
Robert. On Wed, Aug 5, 2009 at 2:44 PM, Mathias Buhr<[email protected]> wrote: > Thanks again Robert! I really appreciate it. > > I've build a small example which should help to demonstrate the problem. I > removed the post processing since it is not reallly helpful nor the problem. > I hope this helps > > Greetings > Mathias > > Am 05.08.09 14:49, schrieb Robert Osfield: >> >> Hi Mathias, >> >> I can't really give you any recommendation as you are already doing >> custom code w.r.t FBO which means there is too many unknowns for me to >> guess at. >> >> Robert. >> >> On Wed, Aug 5, 2009 at 1:31 PM, Mathias Buhr<[email protected]> wrote: >>> >>> Yes, thats exactly the plan but I need the images back in the FB to get >>> the >>> 3rd party stuff working. This means I have to call >>> glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0) before the call to >>> distortion-code or the function won't work. This assumes the image in >>> GL_BACK and GL_BACK has to be stored to the FBO afterwards. >>> How to do this? >>> >>> Greetings >>> MAthias >>> >>> Am 05.08.09 14:08, schrieb Robert Osfield: >>>> >>>> HI Mathias, >>>> >>>> Given your setup it's pretty clear that you'd need to not use the OSG >>>> in built stereo support (that is implemented internally using >>>> osgUtil::SceneView), and instead setup up two slave camera sets that >>>> do the render to texture/post render for each eye and in the final >>>> step do the checkboard stereo at the same time >>> >>> >>>> Robert. >>>> >>>> On Wed, Aug 5, 2009 at 12:34 PM, Mathias Buhr<[email protected]> >>>> wrote: >>>>> >>>>> Hi Robert, >>>>> >>>>> thank you for your answer. >>>>> I'll try to give some more details on the current setup: >>>>> - multiple physical displays/projectors which overlap to produce a >>>>> single >>>>> (flat-)screen >>>>> - alignment and blending of the displays is done with the 3rd-party >>>>> stuff >>>>> - the displays support checkerboard-stereo >>>>> >>>>> In mono-mode my integration of OSG and the 3rd party stuff works >>>>> perfectly >>>>> and all display do what they are supposed to do. The post-processing is >>>>> done >>>>> in the camera's postDrawCallback without any magic :) The problem >>>>> starts >>>>> when I enable OSGs checkerboard-stereo because the image-distortion in >>>>> the >>>>> postDrawCallback will result in an unusable checkerboard-frame. So >>>>> basically >>>>> I'm trying to get checkerboard-stereo to work. >>>>> Due to the described problem, I need access to the left and right >>>>> frames >>>>> to >>>>> distort them individually. Normally they are "blend together" via >>>>> stenciling >>>>> in osg::RenderStage::draw(). As far as I know, there is no direct >>>>> access >>>>> to >>>>> these frames. I could either implement some kind of callback into OSG >>>>> or >>>>> implement a variant of checkerboard-stereo myself. >>>>> Currently I'm trying to render both frames individually to an FBO and >>>>> putting them together afterwards. In this case I would have control of >>>>> both >>>>> frames and I would be able to manipulate them with the help of the >>>>> 3rd-party >>>>> code. osg::Camera::RenderTargetImplementation::FRAME_BUFFER_OBJECT >>>>> wasn't >>>>> able to do the trick since I've found no way to access the FBO OSG >>>>> utilizes. >>>>> Therefore I've tried my own implementation (currently on a single >>>>> display) >>>>> with the following setup and the given result in the post before (take >>>>> a >>>>> look at the attached picture). >>>>> >>>>> The current implementation is very similiar to the osgprerender example >>>>> (stereo is not enabled) except that I'm creating my own FBO in a >>>>> preDrawCallback of the PRE_RENDER cam. This FBO has an attached texture >>>>> and >>>>> is used as the rendertarget for the first (left) (RTT-)camera. >>>>> RenderTargetImplementation for this camera has not been explicitly set. >>>>> The >>>>> texture is attached to a rectangular geometry, which is itself a child >>>>> of >>>>> the osgViewers camera. Unfortunately the result of the RTT looks like >>>>> the >>>>> attached image. The image was saved in the postDrawCallback. I'm pretty >>>>> sure >>>>> I've messed something up or missed something. RTT with OSGs FBO works >>>>> fine >>>>> and I've looked at the code but I didn't find anything. >>>>> >>>>> Does someone have an idea? Or maybe another way to implement >>>>> checkerboard-stereo? It looks like some faces get culled away. If its >>>>> useful >>>>> I'll post some code. >>>>> >>>>> @Robert: I'm not using osgUtils low level stereo right now but I guess >>>>> some >>>>> of the code would later be useful to get the correct left and right >>>>> camera-position-setup. >>>>> >>>>> Nice greetings and thanks for any help or hint! >>>>> Mathias Buhr >>>>> >>>>> P.S.: I was already able to do the distortion with that implementation >>>>> (with >>>>> blitting the FBO-image back to the window-system provided FB to get the >>>>> 3rd >>>>> party stuff working). >>>>> >>>>> >>>>> >>>>> Am 04.08.09 19:14, schrieb Robert Osfield: >>>>>> >>>>>> Hi Mathias, >>>>>> >>>>>> You don't really provide enough info about your overall viewer setup >>>>>> to give a direct answer. It sounds like you are using the OSG's low >>>>>> level stereo support in osgUtil and combining this with a 3rd party >>>>>> code that does distortion correction or similar. Doing low level >>>>>> stereo and distortion correction is really going to work visually even >>>>>> if you got it to work code wise, as the low level stereo support in >>>>>> osgUtil assumes a flat display. >>>>>> >>>>>> Have a bash at explaining what your system is trying to do at a high >>>>>> level and then others will have a better chance of suggesting how to >>>>>> go about it. >>>>>> >>>>>> Robert. >>>>>> >>>>>> On Tue, Aug 4, 2009 at 4:10 PM, Mathias Buhr<[email protected]> >>>>>> wrote: >>>>>> >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> before going into the details of the problem, I'd like to explain >>>>>>> what >>>>>>> I'm >>>>>>> trying to do and what I have done until now. >>>>>>> I have a 3rd-party function/method which is out of my scope. It seems >>>>>>> to >>>>>>> read and write the window-system provided framebuffer and >>>>>>> manipulates/distorts the image. The first implementation was through >>>>>>> calling >>>>>>> this function in a postdraw-callback. Everything works fine this way. >>>>>>> Unfortunately this is not possible if the CHECKBOARD flag is set >>>>>>> because >>>>>>> the >>>>>>> postdraw-callback is called after the complete frame (including the >>>>>>> stenceling for the checkerboard) is rendered. The function would >>>>>>> distort >>>>>>> the >>>>>>> checkerboard. Hence, I have to apply this function for each "eye" >>>>>>> separately. >>>>>>> This seems possible with some changes to OSG itself but it also would >>>>>>> break >>>>>>> the possibilty to upgrade later. So I decided to take another >>>>>>> approach: >>>>>>> >>>>>>> I've tried rendering to an FBO (RTT, similar to osgprerender) but I >>>>>>> can't >>>>>>> apply the function anymore in the postdraw-callback (gives GL >>>>>>> errors). >>>>>>> Since >>>>>>> there is no access to the OSG-managed FBO (for bliting from FBO to >>>>>>> FB) >>>>>>> I >>>>>>> have implemented my own and rendered to that instead. I'll give you a >>>>>>> brief >>>>>>> overview for that: >>>>>>> >>>>>>> MainCamera >>>>>>> - addChild(QUAD_STRIP) //an osg:Geode with >>>>>>> an >>>>>>> osg::Texture2D >>>>>>> - addChild(LeftCamera) >>>>>>> - PreDrawCallback: >>>>>>> - if (!fbo) glGenFramebufferEXT >>>>>>> - glBindFramebufferEXT >>>>>>> - glFramebufferTexture2DEXT //attach the >>>>>>> osg::Texture2D >>>>>>> - PostDrawCallback: >>>>>>> - glBindFramebufferEXT(0) //bind window-system >>>>>>> fb >>>>>>> >>>>>>> LeftCamera is set to PRE_RENDER >>>>>>> >>>>>>> This approach gives me the result which is shown in this picture: >>>>>>> http://www.apparatus.de/test1.png >>>>>>> >>>>>>> Does someone have an idea what is going wrong or what I've missed? >>>>>>> I've >>>>>>> looked at the RenderStage code (and much more :-) ) but I haven't >>>>>>> found >>>>>>> something that might be the problem. >>>>>>> >>>>>>> Or maybe there is another (better) approach to this problem. Any >>>>>>> hints >>>>>>> for >>>>>>> that? >>>>>>> I would appreciate any help! Thank you very much for reading :-) >>>>>>> >>>>>>> Greetings >>>>>>> Mathias >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> osg-users mailing list >>>>>>> [email protected] >>>>>>> >>>>>>> >>>>>>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >>>>>>> >>>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> osg-users mailing list >>>>>> [email protected] >>>>>> >>>>>> >>>>>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> osg-users mailing list >>>>> [email protected] >>>>> >>>>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >>>>> >>>> _______________________________________________ >>>> osg-users mailing list >>>> [email protected] >>>> >>>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >>>> >>> >>> _______________________________________________ >>> osg-users mailing list >>> [email protected] >>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >>> >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
