Celtic knot patterned doorknob and backplate for MY4777 3D printing class. Knots came out looking like pretzels, but that could just be attributed to being German. ;) For the Celtic knot pattern I utilized an OpenScad tile library found here: https://github.com/beanz/celtic-knot-scad All credit for the Celtic Knot library files goes to user "beanz"- thanks for making it publicly available, as it was a large help.