I have a problem regarding the volume-calculation in a specific 3D Dataset. The data consists of 3D multipatches that represent buildings.
One building consists of one or more non- closed multi-polygons that are open from the inside. (E.g. initially polygons forming a building were closed geometries and overlapped – in the data preparation process the inner-walls had been cut away). As a main drawback volume-calculations with use of the typical functions in postgis is not possible (neither for one part of the building nor for the whole building). The dataset I’m talking about can be found under https://shop.swisstopo.admin.ch/en/products/landscape/build3D2 (additional information/ sample data/ LV03)
In ArcGIS I tried to approximate the volumes with a convex/concave hull (minimum-bounding-volume) neither one did lead to useful results since the deviations from actual volumes were too high. 3D-union could be a possible remedy but since the multi-polygons do no more overlap, the function cannot be applied.
Are there any solutions towards a more accurate approximation of the buildings volumes? (any software tools welcome)