. Introduction Garment CAD technology is the use of computer technology to assist the design of garment product. Compared to other mechanical product, garment CAD has to address some special issues. Firstly, it models soft material with low bending stiffness rather than rigid solid objects
Secondly, garment components such as collar and sleeve, are assembled together following specific pattern-making rules which are totally different from the conventional assembly methods. Thirdly, while the garment is constructed from 2D patterns, the quality of fit is evaluated on 3D human models. Based on these observations, garment CAD is a unique research area that has attracted considerable attentions. Early garment CAD focused on 2D pattern drafting and modification. The pattern-making techniques in 2D CAD systems mainly consist of two parts : (1) individual pattern generation based on parametric design; (2) individual pattern altering based on grading rules. Since garment is more flexible than other industrial products, the constraint types used in both parametric design and the grading rules depend on pattern makers’ experience which is case-sensitive: for example, different experiences are needed for different apparel patterns such as suit, jean and shirt. The well recognized flowchart of 2D garment CAD systems go through the phases of fashion style design, pattern design, pattern grading and marker making. Some typical commercial softwares of 2D garment CAD include Toray-Acs in Japan , Gerber in United States , Investronica in Spain , Lectra in France . To release the heavy dependencies on pattern-masters’ experience in 2D systems, 3D garment CAD methods with the technologies of human body measurement are studied and proposed as an alternative solution to non-expert users. The key techniques include 3D human body measurement and modeling, 3D garment design on digital human models, 3D draping simulation, and 2D pattern generation from 3D space. Two well known commercial softwares of 3D garment systems are AssystBullmer in German  and Dessingsim in Japan . Garment design and simulation are intensively studied in the fields of both computer graphics and computer-aided design. In this paper we present a detailed survey on CAD methods in 3D garment design, showing their promising characteristics and their relationship to 2D CAD methods. For the state-of-the-art techniques in garment animation and rendering, the reader is referred to the monographs [47,100] and the excellent survey work in [22,97]. This survey is partially based on the authors’ experience on building the 3D garment CAD system developed at the Hong Kong University of Science and Technology. The second author also co-organized the ACM SIGGRAPH’۰۵ Course Notes , from which some material presented here comes. The overall structure of this paper is aimed at presenting a systematic view of development of the 3D garment CAD platform. This paper is organized as follows. Section 1 covers the introduction of 2D and 3D Garment CAD platforms. Section 2 presents the basic approaches. Section 3 describes the human modeling and Section 4 covers the garment models. Section 5 details the draping methods and Section 6 outlines the 3D to 2D pattern transformation. Section 7 reviews the geometric detail modeling approaches and Section 8 summarizes the parallel computation and GPU acceleration techniques. Section 9 provides a perspective for future directions and Section 10 concludes the review. 2. Basic approaches In this section, we outline the basic approaches in 3D garment design. Based on this foundation, in subsequence sections, we will review incremental progresses towards some more advanced CAD methods in garment design.
Scelerisque ullamcorper non
Maecenas hac vestibulum a hac cras nam a ullam corper integer adipiscing aliquam ornare sed ullamcorper placerat cras cras fringilla condimentum quis potenti sodales primis fames accumsan a quis justo. Condimentum a a viverra suspendisse libero vestibulum amet suspendisse a tincidunt curabitur himenaeos elementum odio placerat ultricies. Urna risus adipiscing curae condimentum blandit aliquet hac potenti mus.