I'm not sure if it helps, but for my "offscreen" FBO rendering I created 1 pixel size window using the windows API and set it's handle as the output of the viewer. the RTT was fine rendering texture size images.
I also tried making the window invisible and 0 pixels size but I don't remember what were the results :) (I guess it didn't work) Guy. ----- Original Message ----- From: "Robert Osfield" <[EMAIL PROTECTED]> To: "OpenSceneGraph Users" <osg-users@lists.openscenegraph.org> Sent: Monday, November 26, 2007 2:51 PM Subject: Re: [osg-users] Offscreen rendering without visible window > Hi Himar, > > Pbuffer is the normal way to render off screen without a window. FBO > requirs an already createdd graphics context to work, they aren't a > replacement of Pbuffer, just the render to texture support that FBO > supplies. FBO's are just part of an OpenGL graphics context state, > they don't have any window creation support themselves. > > Robert. > > On Nov 26, 2007 11:41 AM, Himar Carmona <[EMAIL PROTECTED]> wrote: > > > > > > > > Hi, > > > > i have some questions regarding Pbuffers, FBO, and offscreen rendering. I'm > > not showing the final render on a window but retrieving it with glReadPixels > > for CPU processing. > > > > 1) is there any method to create a Graphics Context without any visible > > window other than using pbuffer = true in traits (on Windows XP)? > > > > I have read that Frame Buffer Object (FBO) replaces much of the > > functionality of PBuffers (Simon Green slides about FBO) and that they have > > better performance. > > > > 2) Can FBO's be used without using PBuffer to establish the > > GraphicsContext? Since they need one, how? > > > > Since FBO's are established at camera objects, is there any method to read > > back the rendered pixels (other than doing it myself with glReadPixels)? Is > > perhaps Image the correct path? > > > > 3) If the desired size of the rendered result changes, i have to recreate > > the pbuffer manually creating a new graphics context with the new size. If i > > use FBO, will i > > have to manually resize it, or it is done by the camera? > > > > I have already achieved doing it with pbuffers, but i will do the rendering > > with FBO also and compare both methods (until replies, using pbuffer to > > create de GC). > > > > > > Thanks a lot. > > > > PD: StatsHandler fails to create the HUD camera if the main camera's > > graphics context is PixelBufferWin32 instead of GraphicsWindowWin32. It > > doesn't found a correct GraphicsContext. > > Is this perhaps a bug? > > > > PPD: Any ideas when will the programming guide book be available ? > > _______________________________________________ > > 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
