Oloid developable surface mathematical sculpture

Have you ever seen an object that is not a ball but can roll? Today I will take you to see these interesting and strange shapes. Oloid is the name of a three-dimensional surface. It was invented by German architect and mechanical engineer Paul Schatz in 1929. Speaking of the name Oloid, there is an interesting story. At first, Schatz named it polysomatoloid, but then he decided no one could pronounce it, so he simply shortened the word to Oloid. Oloid is composed of 2 mutually perpendicular circles. It has very peculiar geometric properties. First, unlike a cube, it has no corners. Can be fully expanded into a flat surface. Display unique mathematical properties Oloid can be flattened. Its shape after being flattened is like this - After playing with Oloid for a while, you may find that after the Oloid rolls for a week, the area it draws on the plane is exactly the shape it flattens out. In other words, when scrolling, every point on its surface will come into contact with the table at some point. This is still very different from the way cylinders and spheres roll. “If the distance of two centers of disk is equal to the radius, then the convex hull produces another figure that rolls smoothly and is known as the oloid. ” — (PAUL SCHATZ, 1975)