3.0.0-draft.2021.12.01.1

This is a new release of the draft OGC CityGML 3.0 GML Encodings.

The XML schemas and example datasets available from here reflect the CityGML 3.0 Conceptual Model as published in the 3.0.0-final.2021.02.23 release of the Conceputal Model and in OGC standard No. 20-010 OGC City Geography Markup Language (CityGML) Part 1: Conceptual Model Standard.

Changes to the previous release:

• The XML schemas represent the final consensus regarding the inline/byReference definitions for the associations. The attached PDF illustrates these definitions.
• The file cityGMLBase.xsd was renamed to core.xsd.
• A profile file CityGML.xsd that imports the XML schemas of all CityGML modules was added.
• More example datasets were added. All datasets validate against the XML schemas.
• Rules for the use of CityObjectRelation and XLink for linking geometries and features that are shared by multiple (top-level) features were specified, see attached PDF.
• Rules for how to deal with association classes in the GML encoding were defined, see attached PDF. The XML schemas in this release were derived based on the rule of creating an Implementation Model that converts the association classes CityObjectRelation and Role into intermediate classes, allowing in this way for the desired encoding of these association classes.