Re: OGC standards for 3d geometries?

Hi Bill,

The most comprehensive standard for representing city data is CityGML (http://www.opengeospatial.org/standards/citygml <http://www.opengeospatial.org/standards/citygml> and https://www.citygml.org/ <https://www.citygml.org/>). The standard can represent all that you have described and can do so in different levels of detail, so everything from roofs or footprints to very detailed 3D models of everything in a building.

Best Regards,
Scott
> On Oct 24, 2017, at 11:41 AM, Bill Roberts <bill@swirrl.com> wrote:
> 
> Dear spatial data friends
> 
> Just thinking about some spatial data in a city context and looking for pointers to the recommended approach or state of the art for representing 3D geometries in the spectrum of OGC standards?  Presumably you can define a surface representing the 'top' of buildings, and another surface defining the 'ground'. What do you do if you want something more complex? Perhaps floors within a building, or surface, tunnels, flyovers etc?
> 
> Thanks in advance for any good links or advice
> 
> Best regards
> 
> Bill