This paper presents two geometric operations–constrained curve beautification and polygonal mesh scissoring–for a sketch-based Computer-Aided Design (CAD) tool for the configuration design of automobile instrument panels. Using the proposed sketch- based CAD, industrial designers and mechanical engineers can work together closely to perform the early-stage configuration design efficiently by drawing candidate sub- panel boundaries on the laser-digitized data of a clay model or a rough CAD model from design sketches.
The proposed system supports two geometric operations essential to the collaborative work between industrial designers and mechanical engineers: (1) the beautification of hand-drawn curves, and (2) the scissoring of the instrumental panel to partition it into a set of sub-panels. Although similar geometric operations are available in current commercial CAD packages, they are not targeted toward early-stage collaborative work and are cumbersome and time-consuming to use.
The proposed constrained beautification takes as input a free-hand sketch stroke and beautifies it by snapping the stroke to an existing geometric feature, an offset of the geometric feature, or a predefined geometry such as a line, circular arc, or elliptic arc. Once a set of beautified strokes is connected to form a loop, the inside of the loop can be cut out using the polygonal mesh scissoring operation. The effectiveness of the proposed sketch-based CAD is demonstrated by applying the system to several test cases.