Optimization On The Realism Of The Virtual PU Fabric’s Softness

Under the background of the development of graphics technology and the deepening of digital application,the key task of the development of clothing industry has gradually become digital and intelligent.The key problem of 3D display of virtual digital clothing lies in the realistic expression of fabric texture.Leather industry is an important people’s livelihood industry in our country,in recent years,under the background of national deepening reform,leather industry transformation and upgrading in our country made initial results,more and more research focuses on application of virtual simulation technology on leather fabric.However,the simulated reality of virtual leather fabric is not ideal,especially in terms of softness.Virtual leather is more rigid and stiff than real leather fabric,with poor flexibility.Therefore,based on Style 3D virtual fitting software,this study proposed an optimization model of PU fabric simulating soft and realistic,which could provide reference for optimizing PU fabric or further studying the simulation authenticity of leather fabric in virtual fitting software.The main contents and results of this study are as follows:1.Determination of softness evaluation method and construction of virtual softness test conditions.Based on the differences between virtual system and real environment,through literature research,the droplet method is adopted to test the softness of virtual and practical fabrics,and the same virtual sample test conditions are constructed according to the real sample test conditions.Forty-nine pieces of PU fabric were selected for real and virtual softness test in three Yarn directions,and 294 practical and virtual softness test images were obtained.MATLAB program was used to read the softness index data of the virtual and real softness test images,and then the regression analysis was carried out on the real softness index and Anti-bending length,and the regression model of the real softness index and Anti-bending length was built.2.The contribution rate of physical property parameters to the softness index of virtual fabric was studied.Based on the correlation analysis between the virtual softness index and the physical property parameters,it is concluded that the five physical property parameters of the Bending strength of weft yarn,Bending strength of warp yarn,Bending strength of twill yarn,gram weight and thickness are linearly correlated with the softness index.Then cluster analysis was conducted on the difference between virtual and real values,and the samples were divided into three categories.One fabric of each category was randomly selected for orthogonal experiment based on the physical property parameters linearly related to the softness index.The regression analysis of the experimental results showed that the contribution rate of curved weft yarn to the droplet area of the softness index was the largest,and that of curved skew yarn to the droplet width and height was the largest.3.The physical property optimization model of virtual PU fabric was constructed and verified.Based on the contribution rate of physical property parameters to the softness index of virtual fabric,the physical property of PU was optimized and adjusted by subjective evaluation.Then,the physical property parameters before and after adjustment were fitted by polynomial fitting method based on the least square method,and the physical property optimization model of virtual PU fabric was obtained.By means of subjective and objective evaluation,3 fabrics were randomly selected from 49 fabric samples for model verification.The experimental results show that the optimized model can significantly improve the sense of softness and authenticity of virtual PU fabrics.