A constructive approach toward a parametric pattern-making model

Abstract

The made-to-measure technique is created to accommodate the requirement of mass customization. A parametric design in various made-to-measure techniques is considered as a significant solution, however, variant programming as a parametric design has its limitation in principle, scope and operation. This paper proposes a novel approach based on variable and geometric constraint to generate a parametric pattern-making model. In an interactive and graphical environment, at the same time that geometric entities are created, geometric constraints between entities are identified, constructed and added into a constraint graph which represents the sequence of construction and constraints, thus it also holds a set of rules and knowledge in pattern-making. To reduce the cost of time and space, the reversible graph of a constraint graph is introduced to represent a dimension-driven process. Parametric modeling of a pattern is illustrated with the rear panel of a women’s jacket in this paper. First of all, a constraint graph and reversible graph are expressed using an adjacent constraint list and an adjacent dimension-driven list respectively, then pattern-making process is stored in an adjacent constraint list, when a set of specific values of variables or the properties of an entity is altered, the properties of the relatively constrained entities are recalculated and updated by using an adjacent dimension-driven list and constraint solving algorithm. The experiments show that the approach has the advantage of the interactive construction of a pattern and convenient operation similar to conventional garment CAD, and the implementation of the dimension-driven process and entity-edited function of parametric pattern model.