I need some help understanding and fixing the challenge with this 3D model please [-> citjsnClean_cput3d_25m-str_solid.json]
If I parse the file through val3dity and check the 3D primitives; my concern is the 303 NON_MANIFOLD_CASE error. Make sure to select **Validation options** and set Snap tolerance to 0.0001
If I look at the model (say: CityJSON ninja) and try to find which features are creating the issue it becomes clear these are objects that are connected ---that share vertices and edges.
a) Are the shell surfaces oriented consistently? Do their Normals point outward? ---Am I fixing the right problem?
b) Is there a ---hidden--- polygon (a duplicate surface where the individual models touch) that I am unaware of / can't see?
c) How will this error affect the usability of the model? What can I now NOT do with the model?