Stitching Simulation Of 3D Virtual Garments

Currently,3D garments are mainly created by stitching 2D garment patterns on 3D human models. Its general process is as follows:Firstly,2D patterns are discretized into rectangular or triangular meshes; secondly 2D patterns are interactively positioned near the 3D human bodies; thirdly, the stitching pairs are set among the 2D patterns; finally, patterns are stitched together on the 3D human models to form realistic 3D garment models based on physics. This thesis studied several important problems in the 3D garment modeling and proposed corresponding solutions, which are detailed as follows.(1) In order to simulation different kinds of stitching, such as the tightening effect of the elastic belt, the 2D patterns should be triangulated properly, which is difficult to most existing 3D garment modeling systems. In this thesis, the stitching requirements are converted into various geometric constraints in 2D pattern triangulation. Using such triangulated 2D patterns, a lot of stitching effects can be simulated based on physics.(2) To stitch the patterns into a garment, the patterns should be positioned properly around the human body. Usually, it is realized by directly dragging 2D patterns in 3D space, which however is not easy to operate. In this thesis, a 3D-2D operation mapping has been set, thus the 3D positioning of 2D patterns can be achieved by 2D operations.To tackle with the interference between patterns and the human body or interference among patterns, two interactive methods have been proposed. One is the enveloping method based on 3D feature points; the other is dragging method based on 3D coordinate ball. With these two methods, the positions of patterns can be fine tuned, which is useful to remove the interference.(3) In modeling complicated garments, the number of stitching pairs is usually more than tens or even more. In most existing systems, stitching pairs are set up manually, which greatly restricts the garment modeling efficiency. In this thesis, a bottom-up method for setting stitching information based on the multi-layer feature is proposed, which can automatically solve the problem of equal-length suture between the patterns. Thus automation degree of garment stitching process is improved.Based on the above research, a 3D garment stitching system was developed. The system has following functions:1) Triangulating 2D patterns with constraints to meet the requirements of garment sewing; 2) Positioning or editing patterns in 3D space conveniently by 2D operations; 3) Setting stitching information intelligently; 4) Stitching and draping simulation based on Physics.