Prague—Three-Dimensional Digital Model of Buildings

These views show three-dimensional data in Prague including terrain with buildings, trees, and bridges. This work began in 2001, and by the end of 2003, more than 120,000 three-dimensional buildings were created covering more than 160 square kilometers.

Aerial photos at 1:7,000 scale were processed using MicroStation/J, and final files were converted into three-dimensional shapefile format. Three-dimensional building layers were created from two-dimensional building layers, which are components of the Digital Reference Maps of Prague.

All objects of the three-dimensional layer obtained the corresponding unique identifiers from the two-dimensional layer and were classified into categories including vertical building walls, flat roofs, inclined roofs, extensions and dormers, chimneys, towers, ventilators, and air conditioners. Roofs were constructed from measured rooflines and ridges by using auxiliary triangles with minimal impact to the viewshed.

Only notable towers on the roofs were included. Dormers, chimneys, and protrusions less than two meters wide and one square meter in area were ignored. Bridges were created according to the aerial photographs. Trees were developed schematically for parklands, avenues with trees four meters in height, and solitary trees.