https://r1132100503382-eu1-3dswym.3dexperience.3ds.com/#community:SNKdMgXCR8SJqa8lpbe7IQ/post:H-0KrNiAQZ6JnaIL-Ogh4g
This is a link to a post for detail on the modeling and the related 3dxml.
following my post on Doyle spiral, when you apply mobius transformation to it, you can get a double spiral like below.
the pictures are rendered with CATIA Live rendering. green is leather and beige is wood.
