The problem here is the clash of two different mindsets, computer graphics people versus knowledge engineering people. The first prefer scene graphs, which are well understood as Braden pointed out, and are good for rendering. The second prefer semantic descriptions of objects and their relationships, which is slightly less well understood. Striving for a mix of both bears the potential for disaster, or at least to bad compromises as you pointed out.
That said, I'm actually quite happy with the current VOS model. The flexible typing allows a vobject to be both a semantic and geometric entity. It can be a misc:Avatar with descriptive properties, and a a3dl:Cone heading a scene graph structure. There are even child vobjects which are useful to both aspects, e.g. a3dl:position & friends. So far, this approach has worked out nicely, right? What I'd like to do is improve this model in a few places, from a semantics point of view. For example, an a3dl:bounds child specifying the rough size and shape of a 3D entity would be helpful. It could give non-visual clients a better understanding of a scene, without requiring them to understand the actual scene graph data in order to compute this information. Another point is the relation between the sector and its contents. So far, the relations only specify generic membership, as a set of conceptually unsorted and arbitrarily chosen contextual names. This does not mean anything to anybody, neither from a semantic nor scene graph view. I'd like to see a more structured approach here, using proper "role" names instead. For example, "m:avatar" for user avatars, "m:scenery" for (static) background entities, and so on. This makes it much easier for a client to select child vobjects of interest for inspection and caching. Regards, Karsten Otto (kao) _______________________________________________ vos-d mailing list vos-d@interreality.org http://www.interreality.org/cgi-bin/mailman/listinfo/vos-d
