New continuous level-of-detail algorithm and its application in virtual endoscopy

Abstract

With the increasing of medical image datasets, the 3D model obtained by reconstruction often incorporates millions of triangles that make real time rendering very difficult. Progressive Mesh (PM) had been developed to address the above problem of view-dependent level-of-detail control, but its speed can’t meet the requirement of virtual endoscopy. In this study, we developed a new view-dependent continuous level-of-detail (CLOD) algorithm for triangle meshes with subdivision connectivity. First, the mesh was simplified in hierarchy to get the simplest mesh (called as base domain), then each hierarchy of the simplified mesh was parameterized to map to the base domain, and finally the view-dependent subdivision was used to resample the mesh to get a multi-resolution model. We constructed an index to record the changes of view parameters by the adaptive octree so as to make full use of the reusability of the adjacent frame and reduce the dynamic changes of the selected levels of detail. We tested our algorithm in several different datasets. The experiments showed that our method is efficient and easy to implement, and the model can be rendered in real time to meet the requirement of virtual endoscopy.