How is Kokichi Sugihara' rounding square made? I have no idea, but I made this clone by intersecting an extruded square and cylinder together at a 90 degree angle to one another.

Please consider supporting the professor himself: https://www.seomagic-usa.com/product_info.php/products_id/2446 I do not claim in any way this is my idea

If he finds this model and would prefer me take it down I will. I took it as a challenge to replicate it as best I could, and it's not perfect, his is of course much better and has a stronger illusion, but I think my version gets 90% there.

This model is intended to be used as a teaching aid to help in the understanding of the illusion. To fully complete the model two must be made and then glued together so that the wave is consistent along all sides.