Anamorphosis, or variable geometry, it the art of creating a work that must be viewed from specific vantage points to see an intended form. Georges Rousse is one of the major practitioners of the form.
![](https://i0.wp.com/boingboing.net/wp-content/uploads/2020/08/george-rousse-01.jpg?resize=826%2C459&ssl=1)
Here's are nice overviews of some of his finished works:
Image: YouTube / Musée de l'Homme