Knit topological shapes

It is possible to construct topological shape via knitting. In HK this may be done on circulars. One out of many tutorials may be found here, and the mathematical knitting is a very good, extensive resource.

A recent forum post on knitting such shapes on the machine led me to dig out an old sample of mine knit with brass wire and holding on the km flatbed; since I never actually determined an end use, the donut hole inner seam was never joined.
in this view the piece isĀ about 3 inches in height, and 8 inches across

a side view