Hi Julian, Have you tried using osg::LightModel to turn on GL_LIGHT_MODEL_LOCAL_VIEWER? It's often necessary in multi-wall setups.... -- Terry Welsh / mogumbo 'at' gmail.com www.reallyslick.com / www.mogumbo.com
> > Message: 3 > Date: Mon, 06 Jul 2009 16:28:10 +1200 > From: Julian Looser <li...@roarmot.co.nz> > Subject: [osg-users] Consistent lighting across different cameras > To: OpenSceneGraph Users <osg-users@lists.openscenegraph.org> > Message-ID: <4a517d5a.5060...@roarmot.co.nz> > Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" > > Hi, > > I am using OSG in a multi-wall stereo rendering environment. We have > three walls, and we render both a left and right eye view for each wall. > To do this, in my application I create six osg::Cameras and update their > projection and view matrices each frame based on head-tracking. I add > the same subgraph under each camera, and I get a seamless 3D scene > across the three walls. So far so good. > > My problem is with lighting. Although the 3D geometry is rendered in the > right place, it isn't lit correctly. For example, sometimes the left > view might be much brighter than the center view, which in turn is > brighter than the right view. This has me confused because all six > cameras are rendering the exact same scene, and the light is part of the > scene (rather than a head-light of the viewer for example). > > My scene graph is set up basically like this (just showing three rather > than six cameras). The cameras all share the same child subgraph, and > just render to viewports next to each other across a window. > > root > -- camera (mv & proj for left wall) > --- model > --- lightsource > -- camera (mv & proj for center wall) > --- model > --- lightsource > -- camera (mv & proj for right wall) > --- model > --- lightsource > > I've attached a picture of the effect I'm getting. What I expected would > be that the object (just a long red box) would be smoothly lit along its > length. However, when it spans across my three views, you can see it's > darker or lighter in each view, suggesting that the lightsource isn't in > the same place within each rendering. > > Am I putting my lightsource in the wrong place in the scene graph? I > thought it should be a sibling to what you want lit? Even though the > projection and view matrices are different for each camera, the lighting > should be consistent, right? > > I'm using a composite viewer, and each view I create I've set the > lighting mode to NO_LIGHT, so I don't think it's a default light causing > any trouble. The only light should be the one in my scene. > > If you have any ideas why this is happening I would really appreciate > hearing them! :-) > Thanks, > Julian. > >
_______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
