Hi, I've exhausted what references I could find without really coming up with a good way of doing this, so I am hoping someone can advise me on an efficient method of achieving the following outcome in OSG.
I have an arbitrary, large number of nodes scene that I don't control the contents of before it's loaded. (eg, assume a giant world scene that is created by an artist) I would like to render the same scene in two views, without duplicating the nodes or assets (memory constraints). Lets say View A renders the scene as normal, View B renders the scene in an alternate mode (lets say, changes the output pixel from colour to greyscale for discussion purposes). The current method uses a bool Uniform that is set on each camera and the fragment shader checks the bool to tell which view it is rendering in and changes the output pixel accordingly. This seems "bad" to me. It works, but surely there's got to be a better way than doing a branch (or multiple branches) in the fragment shader. Ideally I would create two statesets (with optimal shaders etc), and switch between them at render time. So I was thinking I might be able to use one of the various callback methods. Eg, I could attach an update callback to each model in the scene that checks "something" unique to each view, and sets the state as appropriate. However, I'm not sure if the update callback is called once for each view, or only once per frame etc. If the update callback is called per view, what's a fast way to check which view is the current render pass etc? Would a better method be to use the draw callback on Drawables perhaps? Thank for any help/advice you can give me. Cheers, Damian ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=63246#63246 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
