Evaluation And Simulation Of Female Breast Deformation In BRA

In recent years, the concept of Electronic Made to Measure (EMTM) is accecpted widely. And the three-dimensional human virtual modeling is one of the keys to the implementation of EMTM. And its shape determines the final effect of custom clothing. However, the three-dimensional human virtual model should not only be based on the correct description of naked human body measurement, but also the deformation effect of the body wearing underwear (such as bra). What is more, it would be the basis of clothing customization and vitual showing.Changing the research ideas from measuring and analysising the shape of human body in a single state, the pupose of the paper is to connect the characteristics of naked body to the breast shape in bra. Generally, the final effect in bra is affected by both of body shape and structcure of bra. However, bra always is designed based on body shape, and the styles are various and develping. So through applying a fixed base bra to experiment, the paper focuses on the breast deformable abilities of different kinds of body shape, to find the method to predict and evaluate the deformable effect of breast in bra. The main works and approach in the study can be outlined as follows:1) Deformable characteristics of female breast shape in braComparative experiments of female breast shape before and after wearing bra was designed based on three-dimensional measurement technique. By paired sample T test,19measurments of breast deformation were screened, which were closely related to the pattern making and the final effect of clothing. After screening out4measurements whose t-test significance probabilities P were larger than0.005,15measurments of breast deformation were selected as the characteristic parameters.By the factor anlaysis, they were divided into four groups, to reflect the bust section, stiffness, chubbiness and gathering of breast deformation respectively.2) Entropy-based evaluation model of breast deformationThis paper introduced the entropy theory to objectively evaluate the effect of breast deformation. The15characteristic parameters were selected to evaluate the effect of breast deformation. With the experimental samples, the evaluation index system was established. Through calculating entropy weights and composite scores, the comprehensive evaluation models were established based on the entropy for the breast deformation of cross-section shape, stiffness, chubbiness, and gather respectively. From each aspect, the effect of breast deformation was devided into3categories, weak, moderate and strong. Therefore a total of81categroies was achieved, of which there existed37categories. It was proved that evaluation models can be implemented efficiently, and the classification is effective. Four variables were extracted as the key parameters reflecting the breast deformation. And the linear regression models of the related the characteristic parameters of breast deformation were established finally.3) Prediction model of breast deformable ability based on improved neural network ensemble argrithmThrough the Spearman correlation analysis, the characteristic parameters of naked body shape were extracted, which were correlated significantly to the evaluation scores of4aspects of breast deformation.Then a prediction model of breast deformable ability was constructed with4parallel ensemble neural networks. In this paper, a new method based on K-means cluster analysis was put forwards for achieving the training subsets of component ANNs. Also, the outputs of component ANNs were combined via a Dymaic Weight Distribution Method. It was shown that this approach improved the ensemble generalization abitlity. The proper structure of hidden layer for each of component ANN was determined by Remove Method. Finally, the effects of breast deformation of test samples were simulated, through which the accuracy of model prediction was validated. Especially, the mean correct rates for predicting the deformable effect of cross-section shape, stiffness and chubbiness were above85%.4) Development of the evaluation and prediction software system of breast deformation in braUsing the visualization technology, the intelligent prediction software was programmed with the achievements in the entropy-based evaluation model of breast deformation, ensemble ANNs for breast deformable ability prediction, and the description of the classifications. This software could directly make the qualitative and quantitative evaluation of breast deformation objectively by loading the measurements of body shape before and after wearing bra. In addition, it could predict the4items of breast deformable ablitity for an individual, by inputting the characteristic parameters, and output the quantitative estimate of the four key parameters for the breast deformation in normal bra.This system could be connected with the digital systems used in EMTM, such as three-dimensional body scanner, or the virtual-try-on system. It would be helpful to improve the operational efficiency of EMTM.5) Development of the3-dimensional virtual model for individual breast deformation3-dimensional body shape model for an individual is the basis of pattern making and virtual try-on. However, the breast shape is easily to be affected by bra, which causes the large difference between the measurements before and after wearing bra. What is more, the deformation varies in different body shape. In this research, an innovative implementation was applied to virtualize the breast deformation by controlling the four key parameters. Firstly, the individual breast was modeled on the basis of3D scan data and surface modeling technology. Then SDD (Skeleton Driven Deformation) was applied to transfer an individual naked breast model to the deformated breat in bra, while the expected measurements of the key parmaters were satisfied. In conclusion, the breast deformation in bra was analysized in this research, which plays important roll in fashion design, pattern making and virtual-try-on. The individuals were classificated and evaluated by their breast deformable abilities. On the basis of it, the virtual breast deformation model by parametic controlling was explored. The achievement of this research filled up the blank of female breast deformation analysis and the related virtual simulation, with great value and pratical significance.