Research On Automatic Generation Of Bas-relief From Measurement Data

A relief is a sculpture where a modeled form projects out from a flat background. The current relief CAD softwares mostly design relief through a 2D graphic or image, they need more interaction and it is difficult to design more complex details of the relief, and other issues. This paper researches automatic generation of bas-relief from measurement data. First, it needs to process data from 3D models through scanner, second, compress the 3D models based on curvature analysis and feature extraction, finally, generate a rich embossed relief surface. This method has less interaction, but it has more advantages, such as it can generate rich feature relief, and visual effect close to 3D models. The main contents of this thesis are listed as follows:This thesis presents a simple and efficient algorithm for detecting visibility by improving the Z-Buffer algorithms; get the visible parts of the model in the direction of a given observation. Next step is spliting the silhouette of the visible part to generate precise silhouette, it has a good effect for relief compression.This thesis presents a different algorithm of bas-relief generation, which can maintain the details of the models. The main idea is breaking down relief compression process into two parts, one is whole linear compression, which can retain the overall shape, and another one is details compression, which can generate rich details of the relief based on curvature analysis. Because the algorithm directly modifies the depth values of the triangular mesh model, without solving large linear equations, it is fast and efficient.This thesis research and propose an algorithm of generation line-carved relief. According to the size of the radical curvature of the vertices of the mesh model to extract the feature points, and using dilation and erosion of mathematical morphological operations to optimized the feature points. Finally set these feature points a height to achieve relief generaion. This thesis validates the effectiveness of the algorithm through a large number of examples.