The document describes 3D city models created automatically from open data sources for three areas: Gjakovë, Kosovo using CAD data; Liberec Region, Czechia using laser scan and land use data; and Riga Region, Latvia using elevation models, building footprints, and orthophoto images. The models were created to evaluate different data sources and approaches for automatic 3D city modeling and can be used for visualization, analysis, and crisis management, but not high-precision uses like cadastres. Computing models from laser scan or image data is more time consuming than from CAD data. Improvements could include better computing power, combining multiple data sources, and manual refinements.

1. Overview of Contributions
to:
3D model of buildings
automatically created from open
datasets
By:
Jan Macura
Pavel Hájek
Jakub Kočica
Irena Košková
Rinor Shala

2. Goal
• To create a 3D city map automatically from
source data
• For 3 areas of interest – different size of such
areas
• Have 3 different approaches to implement =>
using of different source data (CAD data,
Laser-scan data, images for photogrammetry)

3. Area of Gjakovë (Kosovo)
• CAD based model
• Used data:
– Data from local providers
– Own created data

4. Area of Gjakovë (Kosovo)
• CAD data containing the footprints of
buildings and contours representing DEM

5. Area of Liberec Region (CZE)
• Used data
– Open Land Use
– Registry Of Territorial Identification, Addresses
And Real Estate (RÚIAN)
– Data from the local authorities and providers

6. Area of Liberec Region (CZE)

7. Area of Liberec Region (CZE)
• Data from laser-scan used for creating DEM
and DSM
• Data about the borders of buildings and
forests were obtain and used for
differentiation of buildings and forests from
the point clouds
• Open Land Use was projected into the 2,5
representation to create a distinguished
terrain acording to categories of parcels

8. Area of Riga Region (LV)
• Used data
– Digital Elevation Model over Europe (EU-DEM)
– Buildings’ Footprints
– Data from Eurostat
– Ortophoto Images

9. Area of Riga Region (LV) I.

10. Area of Riga Region (LV) II.

11. Area of Riga Region (LV) III.

12. Area of Riga Region (LV)
I. Used raster calculations for resampling the
rasters representing DEM, buildings and hights
of buildings with the covering of the model with
the georeferenced ortophoto image
II. Comination of the previuos approach with the
polygon based models of buildings
III. Rasters of DEM and polygon of buildings with
the information about their hights were
converted into points and the 3D model was
created based on such points

13. Overview and evaluation
• The created models can be used mainly for:
– Presentations of models
– Using such models as source data for various kinds
of 3D analysis
• Visibilities
• Spatial relationships
• Crisis Management
• …
• But not for example for the purposes of 3D
cadastre – because the models of buildings
are to course for such a use

14. Overview and evaluation
• The advantage of using CAD data is in very
short time of computing such a 3D model
• The computing based on data from laser
scanning or from ortophoto images is very
time consuming and reaching the limitations
of computing capacity of standard PCs

15. Overview and evaluation
• Further improvement:
– Use better machines for computing models
– Improve the appearance of models of buildings by
applying data of higher density, or combining
different sources of data together or using
sophisticated cartographic rules for the
representation of models
– Use a manual work on models – but it is not an
automatic approach