I have few vertical polygons (PolyZM building facades). Now customer asking to merge all adjacent polygons where the angle between two polygons is < 1° or >1°.
I tried with ITopologicaloperator.union function, but after union polygons disappearing.
Kindly help me how to merge these polygons either python or .net.
The topology engine isn't going to directly help you as its 2D, planar, or works from the top down. Since your polygons don't have depth, you'll get some wild results.
One off the wall idea in code is to take the three polygons and create new geometries, transposing the Z to Y coordinates, so you're laying them flat. You can then run the union to get a single flat geometry then reverse the Y to Z to stand it upright. The only concern would be rounding.
Sean... sort-of works, until the geometry is checked again, then any shared geometries (by more than 1 point) in the x,y or z plane get dissolved ... at least in the geometries used in Map or Pro