Inappropriate combination? Bridge, Water and a bad 3D mesh

Saltcity · June 8, 2021, 7:02am

Hello everyone,

i know that water can cause big problems in photogrammetry - but maybe someone has a good tip for me.
In my project (bridge over water reservoir) is the calculated point cloud of the structure work very blurry- probably because of reflections.

I have set the calculating area above sea-level and edited the point cloud in the ray cloud and turned some areas as “disabled”.
The problems:

The edges of the bridge are very blurry and there are no clear borders in the orthophoto.
In the 3D-Mesh are the bridge pillars disappearing (photo), which is an no-go for the model.

Has anyone a good workflow for modelling bridges (over water)?

bridge_3D-Multi_report.pdf (1.2 MB)

Thanks!

Blaz · July 9, 2021, 9:36am

Hi @Saltcity,

Editing the dense point cloud by assigning points to the disabled group is recommended as those points are not taken into account for the 3D textured mesh generation.

If the results are still not satisfactory, then you could also consider the following:

Add surfaces as constraints to keep the edges sharer.
Change the processing options for the mesh generation, by increasing the Octree Depth.

Often it also helps to limit the area of the reconstruction. I would suggest you to use the processing area to define where the mesh should be generated.

Hope this helps,