Abstract:

Objective In order to solve the problem of ambiguity in the amount of front crotch bulge in men's underwear pattern and the problem of ill-fitting crotch of underwear, a surface simulation model of waist, hip and crotch of male human body was established by extracting point cloud data, and a well-fitting men's underwear pattern was generated based on the surface model to improve the comfort of wearing men's underwear by improving the underwear pattern, and also to broaden the new idea of fast access to the fit and body-fitting clothing pattern.

Method A 3-D body scanner was used to obtain the point cloud data of the waist, hip and crotch of the experimental subject, and the point cloud coordinate set was extracted from the point cloud data using reverse engineering software to describe the waist, hip and crotch morphology. NURBS curve and surface principle were used to construct the waist, hip and crotch surface model, the 3-D surface was developed into a 2-D plane in Solidworks software, and the developed plane was processed using ET software to generate a fitted digital underwear pattern.

Results Using the 3-D body scanner to obtain the point cloud data of the male mannequin, 7 feature sections characterizing the morphology of the waist, hip and crotch were selected, and 50 equidistant points of each feature section were extracted from the point cloud data to form a point cloud coordinate set as indicated in Fig. 2(b) for the point cloud coordinate set imported into Solidworks software. The male waist, hip and crotch were reasonably divided into 16 areas, and NURBS curves and surfaces were constructed based on the information of point coordinates in the point cloud coordinates set (Fig. 4). The waist, hip and crotch surface models were established in Solidworks software by using common connecting lines of adjacent surfaces, and the surface models were made to accurately describe the body surface morphology of the waist, hip and crotch. The surface flattening tool was used to flatten the three-dimensional surface into a two-dimensional plane, and the area error ≤1 cm² and the boundary length error ≤1 cm during the flattening process were within the acceptable range of dimensional error. The 2-D plane was exported into the ET software for 4 simple steps (Fig. 7): curve point optimization, plate alignment and shape docking, front and back crotch line adjustment and waist adjustment, and the final digital men's underwear pattern was generated. Based on the virtual fitting of 3-D scanned mannequins in CLO3D software and the actual garment fitting on the male mannequin, the fitting effect was verified for the underwear pattern. Using an air bag contact pressure tester, the pressure test was conducted on seven key parts of the underwear wear. The garment pressure generated by the underwear ranged from 0 to 2.4 kPa (Tab. 4), verifying that the digital underwear version met the garment pressure comfort requirements.

Conclusion For the study of fitted men's underwear patterns, a method is proposed to establish a surface model of the waist and hip crotch and generate a digital men's underwear pattern through the surface model, which solves the problem of ill-fitting men's underwear crotch and provides a new approach for the rapid generation of fitted men's underwear patterns. The digital pattern-making method can be applied to the acquisition of fitted and close-fitting garment patterns by establishing a simulated surface model of the human body form to generate a fitted garment pattern, and the structure of the garment pattern is more in line with the detailed morphological characteristics of the human body.

Key words: digital clothing pattern making, men's underwear pattern, surface model of male waist, hip and crotch, NURBS surface, surface flattening