Extending the GeoSPARQL ontology with full-featured 3D support

[FransKnibbe]

Contributed by Timo Homburg for the white paper "Benefits of Representing Spatial Data using Semantic and Graph Technologies":

GeoSPARQL currently only explicitly supports 2D geometries. However, work has already been done in defining ontologies for 3D geometries (e.g. https://github.com/w3c-geom-cg/geom or https://www.web3d.org/working-groups/x3d-semantic-web/charter). These ontologies should be checked and integrated into, or merged with, the GeoSPARQL ontology.

[situx]

Added to the tracker as part of http://ogc.standardstracker.org/show_request.cgi?id=628

[jabhay]

MoSCoW poll created

[omshinde]

Hello! Thank you for the great efforts and for including this feature extension in Milestone GeoSPARQL 2.0. I understood (from here) that the current functions would work in 2.5D, meaning the spatial relations would only be evaluated in 2D and the z attribute (height or depth) would be passed on as an attribute.

So, if I have two bounding volumes, V1 and V2, then I can check if they intersect in 2D space but I can not check till what elevation they do intersect (my bad for putting it naively). Is this correct?

Also, since it is planned out for Milestone GeoSPARQL 2.0, is there a way I can contribute? :see_no_evil:

[situx]

Hi!

You are correct, there are no GeoSPARQL functions with 3D support as of now and also not in the upcoming GeoSPARQL 1.1 release. If your literal format supports 3D geometries, then you can, of course, put them into the knowledge graph (e.g. a WKT Literal with a Polygon Z), but the functions such as intersects etc. will as you describe only consider the 2D X/Y coordinates for evaluation.

We are currently finishing up the GeoSPARQL 1.1 specification and once this specification goes into review at OGC we will begin work on GeoSPARQL 1.2/2.0. That is we will create a new folder for this in this repository and then any pull requests to extend the specification for 3D are welcome. We also have a bi-weekly call you could join if you are interested, also as a Non-OGC member. Please write to our mailing list if you are interested.

[omshinde]

Hi @situx!

Thank you very much. This is very helpful and I am able to store 3D geometry as Polygon Z. Also, thanks for sharing the info on biweekly meetings. I will write to the mailing list. :)

[pbuttigieg]

Very much needed - representation of volumes is key for deep-sea environments too

[omshinde]

We also have a bi-weekly call you could join if you are interested, also as a Non-OGC member. Please write to our mailing list if you are interested.

Hi @situx Can you please share the mailing list to join these calls? I just realized that I didn't take action to join the list. (better late than never though) :) I would love to contribute to this development. Thanks.

[situx]

Hi @omshinde we posted in in the README.md of this repository. geosparql.swg@lists.opengeospatial.org The next meeting is this evening 9pm CET if you are free.

[omshinde]

Thanks @situx ..Apologies, I couldn't yesterday as I had another meeting at the same time. I will attend the next meeting and onwards.