This section provides an overview of feedback received on the current version of the GeoSPARQL standard (version 1.1) regarding 3D usage. It helps to identify some of the barriers to use, and to outline requirements that have not been addressed that may encourage greater uptake.
GeoSPARQL should include ways to represent 3D data in a knowledge graph.
3D data should be included in common 3D formats and 3D data should be includable as a text literal and a file representation.
Some common formats which could be considered for inclusion are:
GeoSPARQL should include ways to define multi-component 3D geometries, whereas each component expresses its own semantics. For example, parts of a building could have different semantics according to the function of the building components and would be classified as such in an RDF graph.
GeoSPARQL should include ways to position 3D geometries in a 3D space. Commonly 3D geometries are rotated, translated and scaled using commonly defined operators in computer graphics. Similar operations are needed for the relative positioning of 3D objects in GeoSPARQL, as properties and potentially as functions.
GeoSPARQL 3D should be aligned to other vocabularies and standard which currently provide 3D support in different knowledge domains. Especially alignments to ifcOWL and the X3D vocabulary would position the GeoSPARQL vocabulary as a link between these different standards.
GeoSPARQL 3D should provide the opportunity to align a local coordinate system in which most 3D geometries are defined with a coordinate reference. While this work might only be partially done within the scope of GeoSPARQL itself, GeoSPARQL should be aligned with the emerging Ontology CRS developments of OGC and provide necessary functions or properties to create the link.
GeoSPARQL 3D should provide the opportunity to execute non-topological query functions on 2D and 3D geometries commonly used in geospatial databases. Proposed extensions include following functions:
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geometry extrusion to the specified line segment
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geometry extrusion to the specified height
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spatiotemporal geometry extrusion to the specified line segment with specific start and end time
This section describes what kind of geometry is available in IFC, and how that relates to (1) different modelling kernels, and (2) geoSPARQL and geospatial geometry engines.
@Thomas Krijnen, Alex Donkers, Pieter Pauwels == to write here please
This section describes in what other ways 3D geometry is currently handled in the Semantic Web, for example in BOT ontology, OMG and FOG ontologies, and few more.