Characterisation of freeform surfaces is an increasingly importance area of metrology. Currently the characterisation of surfaces is performed using data that can be represented by a height map. Modern measurement devices allow the acquisition of surfaces with complex shapes that cannot properly be analysed using the current texture parameters definition. In this paper a method to characterise both freeform surfaces and surfaces with re-entrant features is proposed. Two surface approximation methods are investigated: triangular mesh and Bézier surface. The proposed method will be compared with a method able to extract the ISO 25178-2 areal texture parameters from a triangular mesh.
Pagani, L., Townsend, A., Zeng, W., Lou, S., Blunt, L., Jiang, X. Q., & Scott, P. J. (2019). Towards a new definition of areal surface texture parameters on freeform surface: Re-entrant features and functional parameters. Measurement, 141, 442 - 459. https://doi.org/10.1016/j.measurement.2019.04.027