Simulation Of Three-dimensional Scanned Garment Based On Geometric Modeling

From the generation to application,there was a complex process for 3D virtual garment.It had become an urgent proposition to tackle the problems including how to generate the 3D virtual garment quickly and conveniently and how to realize the reuse of the same garment under different 3D human body shapes and postures.In view of this,a 3D garment Simulation redressing method based on geometric reconstruction was proposed.Taking this as the basis,the generating algorithm of 3D scanning garment,the application of segmentation technology of 3D mesh,3D garment tailoring and seam lines generation,the accurate measurement technology of 3D human body,the 3D garment redressing method based on geometric reconstruction were studied.The main contents of this thesis include:Firstly,a rapid 3D scanning system was built.In this paper,a single-camera surround system based on offline point-cloud generation algorithm was established,which separated the collection of depth map and point-cloud generation algorithm.The speed of scanning was enhanced,and the interference of the rotation of camera on the quality of point-cloud was improved accordingly.Secondly,implementation of the free segmentation system of 3D mesh.In this paper,a free segmentation algorithm for 3D mesh was proposed for seamless editing of 3D primitive garments obtained from 3D scanning,which includes seven steps: 1).Build the triangular mesh with half-edge structure;2).Construct the cutting plane;3).Optimize and sort the cutting path and record the triangular mesh surface passed by the cutting path;4).Classify the passing triangle and split it,then record the generated separation edges simultaneously;5).Separate the triangles that include the separation edges,forming a separation boundary;6).Group and reconstruct the 3D mesh according to the separation boundary;7).Generate seam lines between groups.After multiple tests on the interactive tailoring,automatic tailoring and automatic segmentation of 3D human body,it is proved that the proposed method is an effective approach for mesh segmentation.Thirdly,study of the slicing loops algorithm for automatic garment positioning around human model.Automatic searching of the landmarks of 3D human body and 3D garment was the key to realize the automatic redressing of 3D garment.In order to locate the landmarks of 3D human body and 3D garment accurately,the slicing loops algorithm was investigated and improved in this paper.Besides,the types of loop connections were classified and analyzed to adapt to the morphological characteristics of 3D human body and 3D garment.Fourthly,the study of the automatic generation of 3D garment patch based on the landmarks of the garment.Automatic generation and ordering of garment patch were the fundamental requirement for various applications.Current methods usually took the 2D garment patches from CAD models,or obtained them from the flatten map of 3D human body,where tedious manual arrangement was inevitable.In this paper,the automated method of generating garment patch from 3D garment and the virtual sewing line was proposed.Based on this approach,the automatic garment patch positioning was solved according to the segmented parts of 3D human body.Fifthly,the study of the redressing way of 3D virtual garment based on geometry deformation.In the process of polymorphic reuse,the procedure of 3D garment redressing needs to achieve two target: fast and accurate while still maintain the natural form of folds and wrinkles.In the context of virtual dressing,a geometrically-based fast redressing method was proposed.Since this method demands no calculation steps like physical modeling and numerical integration,it can provide a fast and reliable solution for the online dressing system.Meanwhile,benefit from the nature of wrinkle conservation,it can also provide a good initial state for the pretreatment of the physical method,which is closer to the real dressing effect.The 3D garment redressing algorithm based on geometric reconstruction includes three steps: pose matching,geometric sewing of garment patches,and penetration compensation.Through iterative closest point algorithm(ICP),the posture synchronization of 3D garment patches and the corresponding parts of 3d human body was done in this paper.The 3D garment patches were sewn by the seam lines.In addition,the penetrating between the garment and the 3D human body,and among the garment itself were solved.The penetration was detected based on slicing loops.Furthermore,the position recovery was carried out for different kinds of penetration via the subdivision of the penetrated mesh,followed by the positive moving,synchronous moving and reverse moving of the corresponding meshes.In order to maintain the geometric size stability,mean value encoding/decoding algorithm based on Laplacian coordinates was used to adjust the neighborhood of penetration.