It allows us to validate 3D primitives according to the international standard ISO19107. Think of it as PostGIS ST_IsValid, but for 3D primitives (PostGIS only validates 2D primitives).
In short, it verifies whether a 3D primitive respects the definition as given in ISO19107 and GML/CityGML. All the 3D primitives of GML are supported:
Unlike many other validation tools in 3D GIS, inner rings in polygons/surfaces are supported and so are cavities in solids (also called voids or inner shells). However, as is the case for CityGML, only planar and linear primitives are allowed: no curves or spheres or other parametrically-modelled primitives are supported. There is no plan to support these geometries, because val3dity is developed with 3D city models in focus.
val3dity accepts as input:
val3dity has a fairly extensive documentation.
If you encounter a bug, please report it on the issue page.
The source code of the validator is publicly available. The version used online is always the latest commit in master branch.
If you use val3dity for research-purposes and publish, please cite that scientific article (which contains all the details):