Abstract:
Generating point clouds or orthomosaics from photographs can be a very affordable and easy
way of access to valuable information of an object or a surface. Close range photographs,
good acquisition geometry, allows that one can achieve high quality point clouds and
othomosaics, sometimes reaching sub-millimetre accuracy. The authors of this paper, the
three working in the National Laboratory for Civil Engineering of Portugal, are identifying
within the Laboratory, applications where point clouds and orthomosaics can be useful to
studies performed by their colleagues, being that this paper presents the first results.
The “objects” that were under study, and here presented, are: a sample of a rock joint, where
the point clouds will help to characterize the surface roughness and the orthomosaic will
support the studies or the variation of the colour of the surface of the specimen during shear
tests; a scaled model of a breakwater, where point clouds will be used to support the
evaluation of the stability of the structure to the impact of waves; walls of concrete dams, as a
support to visual inspections; a timber beam under stress, where photos can be used to
measure the displacements.
