Here's a star/heart that's the same idea: https://www.myminifactory.com/object/3d-print-ambiguous-star-to-heart-illusion-210605 https://www.myminifactory.com/ob

Here's a star/heart that's the same idea: https://www.myminifactory.com/object/3d-print-ambiguous-star-to-heart-illusion-210605 https://www.myminifactory.com/object/3d-print-ambiguous-star... I've printed it and physically fiddling with it made it much more clear how it worked. I haven't seen a print for that dog, though. In theory, I think you could use Sugihara's approach to automatically generate such a model for most closed curves. That'd be a cool little program that I don't know how to write.