The Parametric Technology Research Of Three-dimensional Garment

With the rapid development of virtual reality technology, 3D garment CAD technology has been widely used in the field of clothing production and design.3D personalized human body model is the basis of 3D garment CAD system, which determines the efficiency and quality of its operation. With the rapid development of the CAD system, the accuracy and the individual requirement of the 3D human body model are more and more high. On the basis of previous research, this paper discusses how to process the 3D human model quickly, conveniently and accurately, so as to meet the requirements of 3D garment CAD and a new personalized human body model generating method and a new personalized human body deformation method are proposed, which provides the basis for the design of 3D garment. The body data of scanning is the initial data of 3D human body model.In this paper, the types of human body model are introduced, and the human body scanning principle and the optimization method of human body data are described.For example, The import method of OBJ and STL model file are introduced with the examples and the direction of a new improted human body model can be adjusted automatically. In the interactive operation of digital 3D garment design system, the user interacts with the system through the input device. Some basic operations such as object scaling, translation, rotation, viewing and so on need to be picked up to get the space object, Some functional operations such as marking the human characteristic curve or the feature points, the standard line of clothing and so on are also depended on the technology of picking up. Therefore, the technology of picking up is a basic operation and technology of the system. In this paper, a space curve modeling method is proposed, which is realized by SharpGL, and the result is satisfactory. The method lays the foundation for the other operation of the system and has great significance for the digital 3D garment design. An octree structure layered bounding box technology is introduced in the method, when picking up a ray from the picked point, we will find the ID number of the ray and the bounding box firstly, then the intersections can be obtained between the ray and the triangles, and the closest point of view will be screened out as the picked point by comparing the depth information of each intersection point, finally, the NURBS curve will be obtained with each picked up point by using the SharGL evaluator.The left and right profiles and the front and rear sections are the frame of the human body in the direction of left and right and the direction of front and back, which determines the human body deformation trend of the before and after direction and the left and right direction. Firstly, the realization method of the front and back sections is described, then, the left and right profiles are fitted with two surfaces and three surfaces respectively, which proves that the combination of the three surface and the two curved surface can fit the left and right surfaces. And the algorithm description of the front and back sections and the left and right profiles are given respectively. On line around the convex hull points sorting is the basis for the creation of parameterized human and human body deformation, the algorithm and sorting for convex hull for confining line set are introduced in the paper, the principle and implementation method of the horizontal section, the collar section and the oblique section are given, and the results are described.The realization of parameterized human model is the most important one of 3D garment CAD, and the deformation of parameterized human body trunk is the core of the deformation of parametric human model deformation. In this paper, a new method of deformation is proposed, parameterized human torso model consist of the contours of the horizontal section and the original human body section and the connecting line of adjacent line. The process of parameterized human body trunk deformation is the process of the contour deformation and the connection, the deformation algorithm is the key of deformation. The human torso model can be divided of neck, shoulder, back, chest, waist and hips by the height of the characteristic line and the characteristic point, and different parts of the contour of the deformation algorithm, the position height of the line is marked by its position. the intersection between the left and the right section and the contour line determines the direction of the lateral deformation, and the intersection of the front and back section and the surrounding line determines the direction of the before and after deformation, the intersection between the left and right profile and the front and back cross sections is the center point of the deformation. when deforming of the feature contour line of different parts, according to the difference between the contour of the template feature contour line and the feature contour line of the target, the corresponding algorithm is used to calculate the deformation size of the front, side and back of the characteristic line firstly, the deformation size of the point between them is obtained according to the angle interpolation. The same position of the contour line has the same deformation algorithm and the deformation parameters of the same position, the size of the deformation parameters of the line is obtained by the contour line and the position of the part's feature contour line.Finally, the theoretical methods of 3D garment design and modeling are discussed, the formation of 3D garment surface, the deformation mode of the driving garment and the method of 3D garment expansion are introduced. At last, the research is summarized, and the development prospects of the subject research are prospected.