(1Vienna Univ. of Technology, Vienna, Austria / 2Government of Lower Austria, Austria)

Outline: With terrestrial laser scanners can now be arbitrarily large amounts of data collected. On the software side the processing is limited by the large number of measurement points. Especially the visualization of 3D point clouds represents a particular challenge to the Software and the aim was to develop a software that allows, without limitation in size of the point cloud a representation of the whole 3D point cloud. The functionality will also allow editing of the data. Color jumps in the presentation should be avoided by the use of semi-transparent circle, so that the individual points fit geometric and by color into each other.

Abstract: Terrestrial laser scanners are used at many excavations for documentation and inventory. For the documentation of the excavation Amphitheatre 1 in Bad Altenburg, Austria the terrestrial laser scanner Riegl LMS Z420i was used. Overall, the entire excavation was covered by about 150 positions. With each scan position the amount of data recorded increases and this leads to performance problems in the visualization of the data. Due to the enormous number of points a consolidated representation of the entire point cloud is not possible with traditional software. The developed software Scanopy allows to present and edit huge amounts of scan points. Furthermore, it is possible to integrate polygonal models and integrate them with the point cloud in a scene together. This allows an exact documentation of large archaeological excavation. Another application is the visualization of polygonal models of different excavation levels. The simplest visualization of point clouds on the screen is a representation of the points as square rectangles. This, however, creates geometric inaccuracies, and colored point clouds are presented with sudden color changes.Presenting the points by using semi-transparent circles the 3D points pass over into each over and lead to more homogenous visual representation of the scanned object. Thus the visual impression of the point cloud will be upgraded considerably. The developed software is demonstrated on the excavation mentioned above.

Keywords: 3D Point Clouds, Visualization, Scanopy