Research And Application Of 3D Last Processing Technology Based On Feature Information

Lasts are important in the shoemaking industry, and are the benchmark of shoe style in the shoemaking technology. The last digital processing technology is required while the computer aided shoemaking technology is spreading all over the world. Pointing to the contradiction of quality and amount of the last data, and based on the analysis of existing data forms, a new form that consists of feature information and simplified mesh was advanced, and correlated technologies were developed.PCA was introduced to adjust the last position automatically. To distill the feature information of last, feature points were classified into three categories and methods were devised for each category. Then feature sizes were calculated.Last mesh simplification is the keystone. Hoppe抯energy function was improved to ensure that last mesh was deformed less where it was nearer to the feature points or there were more feature points around.Using the feature information, feature sizes could be edited on the simplified mesh. Combining of height, width and girth editing, and referring to the national standard of last size, the last was graded and then smoothed.Before manufacturing, the last model must be subdivided to dense mesh. Based on the research of various subdivision schemes, interpolated v3 subdivision was applied. The resulted last must be verified by the feature sizes.Integrating all these technologies, a last base system was built and some of its applications are shown. Finally the works in the thesis were summarized and the future work was put forward.