3D Space

How to represent 3D space?

What data structure(s) ?

Need both metadata (semantic info) & 3D geometry (this is why CityGML is a good fit).

 (Why do we need 3D space?)

* need to provide spatial information via audio cues (how big a space is, reflected sounds, echos) -- requires coarse but variable height

* need to represent multiple stories/floors -- doesn't require variable height; floors could be separate entities.

    For the coming user study, we don't need "true 3D," because we may not emulate advanced aural feedback--it is likely that our study will be with sighted persons, who probably can't take advantage of this. We will use OpenAL to generate basic 3D sound, neglecting echos, etc. This is to save time.

However, we have to parse the CityGML anyway, and we might as well store all the information; if we don't use it now, we'll want it later.

    So how do we concisely and simply represent our 3D space? Most relevant studies are concerned with 2D floorplans.