Influencing Factors on Vertex Normal Accuracy for Triangular Meshes

Vertex normal in triangular meshes is an essential surface attribute for point-based smoothing, mesh simplification and feature detection in fields as machine vision, virtual reality and reverse engineering. In order to investigate how weights of the algorithms for vertex normal estimation influence the vertex normal accuracy, theoretically analyses and experiments for algorithms by comparison are used in this paper. Firstly, advantages and disadvantages of five representational algorithms are discovered by comparing the characteristics of their weighting factors. Next, experimental approaches on sphere surface are presented to construct a series of special triangular meshes for testing. Experimental results show that accuracy of normal estimated is influenced significantly by the corresponding triangles´ quality, and rational fashion of weights with incident angle multiplication and area reciprocal improve the vertex normal accuracy effectively.