PCJohn wrote on 2010-03-19: > Hi Bryan, >> osg::Light is a StateAttribute and osg::LightSource is a Group, so > Light represents the OpenGL state (like the light ID) for a light in > the scene, and LightSource represents the location of that light (note > that LightSource has a Light). >> > And why there is LightSource? What is meaning of it? I think, I can live > just with osg::Light. And really, I used only osg::Light in my > application. Is there any reason for me or anyone else to use > osg::LightSource?
You place the LightSource in the scene graph where you want the light to be positioned. I don't think it is necessary for directional lights (they are infinitely far away, so don't have a position), but say you want a spotlight attached to a train locomotive. You could update osg::Light's position every time the locomotive moves, or you could attach a LightSource to the locomotive's scene graph and have the light placed correctly automatically. HTH, -- Bryan Thrall FlightSafety International [email protected] _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
