And here's what it looks like imported into Cinema4D.

If there's a shading glitch, you're going to need to help me find it, as far as I can tell it is completely glitch free:





And rendered:



I've also attached the OBJ file if you want to test it yourself.


I think you were getting confused about some rough low poly artifacts, when you have a rougher amount of polygons, with triangles connecting from the outer edges to a center point with different shading at each of those points, that looks like what you were thinking was "crossing polygons".

They were not crossing, you were just seeing too much difference in the shading of those vertices being spread across a long polygon.

- Michael