Validation of 3D primitives according to the international standard ISO19107
C++ Python CMake Shell
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README.md

val3dity

val3dity---pronounced 'val-three-dity'---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:

  • <gml:MultiSurface>
  • <gml:CompositeSurface>
  • <gml:Solid>
  • <gml:MultiSolid>
  • <gml:CompositeSolid>

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:

Installation of the command-line tool

We provide the source code that you need to compile with CMake. This is relatively easy under Mac and Linux.

For Windows, we offer an executable, although it's also possible to compile val3dity yourself.

To compile val3dity yourself, you first need to install the following free libraries:

  1. CGAL v4.10+ (<v4.10 will compile and run, but wrong results for one test (error 405))
  2. (CGAL needs to be compiled with the Eigen library)
  3. GEOS
  4. CMake

Under macOS, it's super easy, we suggest using Homebrew:

$ brew install cgal --with-eigen
$ brew install cmake
$ brew install geos

Under Linux (at least Ubuntu), CGAL has to be compiled because apt-get doesn't give you a version with Eigen. Thus, in a nutshell,

  1. download latest CGAL code
  2. install Eigen library: $ sudo apt-get install libeigen3-dev
  3. compile CGAL by first activating the Eigen option in the CMake ($ cmake . -DWITH_Eigen3=ON), or use cmake-gui and activate it (option is called WITH_Eigen3)
  4. export CGAL_DIR=/path/to/CGAL-4.1x which will tell your shell to use that version of CGAL (thus more version of CGAL can be installed on the same computer; see that handy manual)

To compile and run val3dity (from the val3dity folder):

$ mkdir build
$ cd build
$ cmake ..
$ make
$ ./val3dity ../data/cityjson/cube.json

The summary of the validation is reported, and you should see that cube.json contains one valid primitive.

To verify that everything went fine during the compilation, run the unit tests (from the root folder of val3dity; must use Python3):

$ python3 -m pytest --runfull

You shouldn't get any errors

Finally, to see all the options possible:

$ ./val3dity --help

Vagrant development environment

If you are eager to contribute but do not want to fiddle with setting up the required libraries, Vagrant can take care of that. It creates a development environment in a virtual machine, which you can use to compile and run val3dity. For details see VAGRANT.md

Web application

If you don't want to go through the troubles of compiling and/or installing val3dity, we suggest you use the web application. Simply upload your file to our server and get a validation report back. We delete the file as soon as it has been validated (promised!). However, a file is limited to 50MB.

Documentation and help

Read the full documentation at http://geovalidation.bk.tudelft.nl/val3dity/docs/.

The primary channel to communicate with the developers is the Issues section.

If you have a question or came across a bug, please submit an issue there. However we ask you check first whether your problem has already been solved by someone else.