I'm not sure if this answers your question, but... the only portable way to get a floating point depth buffer is with an FBO; you can't attach one to the frame buffer associated with the main display. So the example renders the geometry to an FBO attached to a slave, then displays the results as a texture in the main camera.
Tim On Sun, Jun 3, 2012 at 12:13 AM, Joel Graff <pair_o_gra...@comcast.net> wrote: > Hello, > > I'm trying to learn the intracacies of rendering to textures using osg, and > I've dissected the osgfpdepth example to do it. I've been largely successful > at resolving the code into a much simpler example for rendering using the > color buffer only. > > Anyway, my goal was to have both the main camera and the RTT camera rendering > the same geometry. The RTT camera, of course, would have different state in > it's path that would create a different effect on the geometry. > > However, it seems the osgfpdepth example isn't set up to do this. That is, > depth buffering is enabled on the root node with the code: > > > Code: > > osg::Depth* depth = new osg::Depth( osg::Depth::GEQUAL, 1.0, 0.0); > sceneSS->setAttributeAndModes(depth,(osg::StateAttribute::ON > | osg::StateAttribute::OVERRIDE)); > > > > > Why depth buffering has to be enabled for the slave camera to > render-to-texture I'm not sure, but I do know that doing so means the > geometry isn't rendered by the main camera view. That is, either the main > camera or the RTT camera renders the geometry, but not both. Thus the need > to create a second texture slave camera to render the RTT output to the > screen. > > Given that I'm new to render-to-texture methods and techniques, I've no doubt > there's some obvious reasoning that I've missed. Nevertheless, I'd > appreciate any comments that might illuminate the issue. > > Thanks, > > Joel > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=48005#48005 > > > > > > _______________________________________________ > 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
