Wonky shaded view after import from OBJ format

About 15 years ago I built a house model in FormZ. Recently I had an opportunity to convert it to OBJ format and import it into Rhino 6 (and Rhino 7 gives the same result).

I have tried for hours to clear up this aberration with no success.

Any ideas would be appreciated:

Wonky Shaded Display v01.3dm (42.8 KB)

Hi @MrPelican
I’m not at a computer right now, but it looks like welding. Try Unweld at 0° and then Weld at eg. 80°. Any better?
HTH, Jakob

I was not aware of “welding” but it seems to be the issue I am having. I will study this further… Thank you for your insight and direction.


why not MeshToNURB and MergeAllFaces
same steps and better editing