Robert Osfield wrote: > On Fri, May 15, 2009 at 10:41 AM, Joe L <[email protected]> wrote: >> In our plan, the TDW will have around 30 displays. > > OK, you'll definitely need a cluster for this. >
> > There is a third possible solution would require mods to the core OSG, > or at least subclasses from it, and is something I've been wondering > about for a while. The approach would be to do a distributed render > graph, where you do a cull traversal (or several cull traversal) on > the master for the whole view frustum that gives you a list of > drawables, modelview+projection matrices and state inheritance graph, > then you broad cast this list to slaves on the cluster. These then > traverse this rendering graph and cull out what leaves aren't in their > local view frustum. On each slave you'd cache the state and geometry > and update this only when the master changes their value, to avoid > having to dispatch all this data on each new frame. > I've been thinking about this too, but without the global cull. Are you trying to avoid having a real scene graph on the local nodes and keep lists of drawables and StateSets instead? I would think that broadcasting the dynamic changes to the scene graph would result in less network traffic than broadcasting lists of drawables, but I suppose it depends very much on the application. > The distributed render graph proposal above sits between the low level > distributed GL approach and the high level distributed application > approach like done with Equalizer. The distributed GL approach > requires more network and CPU bandwidth, most doesn't require any > application modifications to do the cluster, while the distributed > application approach minimizes network bandwidth but does require you > to design your application with the cluster in mind. The later > approach is more work, but provides better scalability. > > The distributed render graph approach has the potentially of scaling > reasonable well, while at the same time need little more than a > cluster specific cluster configuration being used in the viewer, so > once you have this inbuilt capability it's would be easy to move from > a single desktop display to a cluster by just changing a viewer > configuration file. > > Robert. Tim _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
