3D polygon geometry repair problem

[JozefBogľarský]

Hello,

I´m trying to do geometry repair for a 3D model of a city. After geometry check, I´ve got many self-intersecting polygon errors, but when I apply repair tool, polygons that represent walls disappear and only polygons of roofs are left. In attribute table, everything is still there, I just can´t see walls on the buildings anymore. 

I looked at this thread repair geometry - self intersections but it didn´t help. 

I´m new to this, so maybe I´m missing some fundamental step in the process, that I´m not aware of. I´ll appreciate any advice. Thanks. 

[DanPatterson_Retired]

Self intersections—The areas of overlap in a polygon will be dissolved.

Looks like that is what happened.  How was the geometry created? Where did it come from?

[JozefBogľarský]

Data were provided by private company, created using photogrammetry software (i think it was Microstation). It was given to me in .dgn format, so I put it into .shp and .gdb. 

[DanPatterson_Retired]

Often other software breaks the rules for self-intersection,  Don't have any recommendations other than trying to ensure that your roof data doesn't have the same attributes as your walls.  A shared line with the same attribute might be the issue