Research On The Surface Rendering Algorithm Based On Delaunay Tetrahedral Subdivision

At present, three dimensional reconstruction of graphic image gained the wide attention in the field of geological and medical care. In the field of health care, it can depicts the three dimensional structure of the object more intuitive and more accurately by the reconstruction of human organs or tissue to help doctors to observe the patients’ lesions and other places of interest. It also helps doctors to analyze the illness of patients to improving the accuracy of medical diagnosis. In geology, it helps researchers to observe and analyze the substances which wanted to be extracted more accurate and effectively to improve the working efficiency of personnel by the three-dimensional reconstruction of the material which has different properties. So the study of three-dimensional reconstruction is very significant.The technology of three-dimensional reconstruction can be divided into two major categories, the Surface rendering and Volume rendering. This article researches the surface rendering algorithm of three-dimensional reconstruction. The algorithm of Surface rendering is simple and easy to realize. Its efficiency is superior to that of volume rendering. Besides, the results of surface rendering algorithms can be used for other scientific processing. So it has been widely used in related fields. The Marching Cube (MC) algorithm is one of the classical methods of surface rendering. The algorithm principle is simple, easy to implement. But it has the problem of topological ambiguity. The Marching Tetrahedral algorithm (MT) is an algorithm which is developed on the Marching Cube algorithm to solve topological ambiguity problem of MC algorithm. But the problem will arise in course of cube dividing into tetrahedron. And the requirements of the data in the traditional surface rendering algorithms are relatively strict. The algorithm first split the cube of the MC algorithm into tetrahedron, Then, extracted the ISO surface from each tetrahedral. Due to the ISO surface in tetrahedral does not have the ambiguity, so the algorithm can solve the topological ambiguity problem of MC method naturally. But there are many subdivision mode in tetrahedral subdivision of the algorithm. Different methods of dissection may produce different results. Therefore, the algorithm has the existence of two senses. In addition, the traditional surface rendering algorithm is difficult to handle irregular cube data, In practical application, it often encounters irregular cube data. In view of the above problems, this paper has improved the surface rendering algorithm. The specific thinking is that it divide the cubes into tetrahedral by the algorithm of Delaunay tetrahedral partition. Then, it extracts the ISO surface from the obtained tetrahedral. Finally, it draws the corresponding image by OPENGL tool.The improved algorithm can solve the problem of dividing ambiguity of the MT algorithm. It can also deal with the irregular cube data to make up for the lack of processing the data of irregular cube of Traditional face rendering algorithm. In addition, the Delaunay tetrahedral subdivision can also reduce the appearance of the narrow triangle in the contour plane. Therefore, the improved algorithm can improve the quality of the extracted contour in a certain degree.