Can anyone help me remember what the name of an infinity type shape that can be modeled but not manufactured? I know this sounds vague but I remember in years past we used a certain shape to test the performance of various 3D CAD programs. It's shaped similar to a twisting triangle or knot.

Maybe someone who used to do the SW demos might remember it. It has a specific name that I thought was common, not something we came up with on our own.

Thanks

Terry G.