Study On 3D Computer Simulation In The Fabric Structure Of Knitted Sweater And Fitting

The purpose of this paper is designing a software on pattern preparation system of knitted sweater computer aided design for domestic hand-knitting plat machine .The computerized flat knitting machine in external usually equits with a well-developed pattern preparation system, including fabric structure simulation, knitted sweater pieces simulation, fitting simulation and so on. But these pattern preparation systems normally need the special computer and special knitting machine, and they are often sold together with the machine. But the internal software on this side is very little, and not well developed. Due to this situation, this subject has done some research on the field, and developed application software possessing the function of knitted sweater structure simulation, clothing pieces simulation and fitting simulation.The software uses APP wizard to build a application based on the dialog box by the strong 3D graphics drawing function of OpenGL's graphics database on the environment of Visual C++ program language.The part of knitted sweater structure 3D simulation can show the three dimensional effect of several basic structures, such as plain, rib, cable, aran and jacquard. First, according to space geometry configuration of plain fabric, a basic 3D weft knitted loop modal has been built on the base of Pierce's 2D loop modal. Based on the loop modal, different loop modal for different structure also need to be built. Then every modal can be implemented by OpenGL, and using the translating function in OpenGL to arrange different loops by rule, different fabric structure can be got. At last, through a series of coordinate transform using the light function in OpenGL, the simulated fabric structure with 3D effect is showed on the computer screen.The parts of clothing pieces simulation can simulate some style consisting of several basic shoulder style, sleeve style and collar style. First, the 2D modal of every kind of basic style should be built, and then every modal was implemented by the manner of drawing polygon in OpenGL. The fabric structure's simulated picture has been stored in the computer by the format of bitmap file. Choosing different structure can get the corresponding simulated picture. And mapping the simulated picture to the clothing pieces modal by using the texture mapping function in OpenGL can implement the simulation of knitted sweater pieces.The part of fitting simulation can simulate the effect picture wearing on body. Storing the clothing pieces simulated picture in the computer by bitmap format and importing the chosen model to the program by the resource of bitmap the simple fitting effect can be simulated in the use of image synthesis technology of Visual C++.The software completes some basic simulation function in pattern preparation system of knitted sweater CAD. By the research work, the development of internal knitted sweater CAD about structure simulation and fitting simulation will be advanced. With the development of knitted sweater CAD system, a new system with more function must be made out to improve the software situation recently.