Research On Some Technologies Of Design Sketch-based Product 3D Model Retrieval

Due to the improvement of the hardware of computer,the development of computer graphics technology and internet technology,and more ways to get 3D models,the quantity of 3D models is increasing at astonishing speed,and the 3D Models are gradually becoming the forth media data type after sound,images and video.In the field of product design,it is very important that how to utilize existing 3D models efficiently for product improvement and innovative design.But it is not easy to find aimed models,so 3D model retrieval technologies come to people's eyes.But existing 3D model retrieval technologies can't serve product design very well.Sketch-based 3D model retrieval technology has been put forward in this thesis.1) Summarize and analyze present status and future trend of retrieval technologies of 3D model,and provide some typical 3D model retrieval systems.2) Analyze the characteristic of off-line and on-line sketch and pro-processing technology of sketch,and then improve the way to pro-process sketch。3) After analyzing the theory of perspective projection and technology of camera calibration,propose a new approach to extract perspective information based on sketch, build bridges between 2D and 3D.4) Based on the classification of feature lines,propose a new approach to extract feature lines of 3D models based on hidden-surface removal and adaptive threshold of dihedral angel.5) Establish eigenvector between on-line sketch and 2D project feature lines based on Fourier transform;discuss the advantage of similarity measurement between on-line sketch and multi-direction projection feature lines.6) Design and develop a 3D model retrieval experimental frame system based on above-mentioned algorithms,improve the retrieval interface that can better serve product design.