A Complex Geometric Surface Extracting Method for Large-Scale Volumetric Data

To address the performance and precision problem of extracting volumetric data using complex geometric surface, we present and implement an efficient surface extraction method based on octree acceleration structure and polygon clipping for visualizing significant field data on arbitrary object surface in 3 D space. This method first applies plane-volume intersection equation to transform the extraction problem of volume cells to 2 D space where an octree acceleration structure based on spatial bounding box is novelly introduced. Then, a clipping algorithm for concave and convex polygons and several optimizations are specifically designed to efficiently calculate intersection polygon. Pre-selection strategy is introduced to dramatically reduce the number of invalid mesh patches in order to improve performance. Finally, this method is integrated into common visual analysis engine. Our experiments show that the proposed method can achieve the surface extraction operation of complex geometry from volumetric dataset generated by numerical simulation with high precision and performance.