Automated Generation of Knit Patterns for Non-developable Surfaces

Abstract

Knitting offers the possibility of creating 3D geometries, including non-developable surfaces, within a single piece of fabric without the necessity of tailoring or stitching. To create a CNC-knitted fabric, a knitting pattern is needed in the form of 2D line-by-line instructions. Currently, these knitting patterns are designed directly in 2D based on developed surfaces, primitives or rationalised schemes for non-developable geometries. Creating such patterns is time-consuming and very difficult for geometries not based on known primitives. This paper presents an approach for the automated generation of knitting patterns for a given 3D geometry. Starting from a 3D mesh, the user defines a knitting direction and the desired loop parameters corresponding to a given machine. The mesh geometry is contoured and subsequently sampled using the defined loop height. Based on the sampling of the contours the corresponding courses are generated and the so-called short-rows are included. The courses are then sampled with the defined loop width for creating the final topology. This is turned into a 2D knitting pattern in the form of squares representing loops course by course. The paper shows two examples of the approach applied to non-developable surfaces: a quarter sphere and a four-valent node.