Surfaces

Harris Matrix-Editor

Visualization of tunnel cracks.

Visualization as point clouds.

"Fresh data" of a tunnel as a point cloud.

Visualisation and visual analysis of high-resolution surface reconstructions for different application areas.

This multi-firm project addresses requirements of twosurveying companies, Dibit and Linsinger ZT and the new media company Imagination. In various application areas surfaces are scanned with an unprecedented accuracy, reaching the sub-millimetre range. The digital representations allow to investigate very small details and observe changes over time from previous scans. This helps to detect damages and decide where and when repairs are necessary. In archaeology surfaces are scanned during an excavation to digitally preserve removed structures which is important for the analysis.

For Dibit we research on a monitoring system that allows to detect cracks in tunnel walls and track their changes over time. It also visualizes forces acting on the surface and the deformation they cause. Visual analysis is complemented by interactive measurement tools working directly on the 3D geometry, adjustable cutting planes and collision detection of profiles running along the tunnel axis.

Linsinger ZT specializes in the survey of cultural heritage sites such as the cathedral of Cologne. To be able to predict and measure potential weak spots due to weathering, we reconstruct geometric surface detail and generate 3D models of the façade from multi-spectral sensors. Photometric stereo methods generate enough detail to detect even changes in surface roughness. Long-term measurements allow the automatic comparison of changes in critical areas, resulting in an early warning system for the renovation planning.

The Harris Matrix is the de-facto standard method for the documentation of excavation projects. The company Imagination offers the Harris Matrix Composer, - a software tool to create and manage Harris Matrices. Temporal aspects are also very important for the archaeological analysis but missing in this tool. Thus, ourresearch addresses this problem by conceiving a combined visualisation of stratigraphic and temporal relations. This enables the dating of finds assigned to stratigraphic layers of the excavation and spatiotemporal reasoning. Furthermore, an interface to a GIS and an interactive 3D viewer will be established to enable linked views between 2D and 3D, which allows a comprehensive scientific analysis.