Unusual Surface

I downloaded the attached file from some educational website. The file has a rectangular surface in it which seems quite normal when you look at it. But trying to divide it via isotrim or doing any kind of paneling on it gives very unusual results. Even populating it with points gives different density of points in different areas.

I’d like to know what’s wrong with this surface and how one can create such surfaces because I do see some utility in it.

folding1.3dm (307.0 KB)


If you turn on isocurves you can see the underlying structure is far from straight
Turn on the controlpoints and you will see how these points are all folded over eachother.