A Comparison of Weighted Average Methods for Computing Normals for Marching Cubes Isosurfaces

摘要

We compare a variety of methods for computing estimates of the vertex normals for triangular mesh surfaces resulting from the marching cubes algorithm. These methods use different weighting schemes for the facets of the vertex star. A rather surprising result is discovered in that using a smaller special subset of the star can yield better results. The experiments are conducted by running synthesized function data where the true normals are known. The accuracy of an approximation method is determined by both the root-mean-square and maximal differences between normal estimates and true normals computed from mathematical formulas. The results are examined and analyzed to identify the strengths and limitations of individual applications.