An optical method for determining an orientation of surface texture of a mechanical part includes: i) acquiring data for a first areal surface topography image using a surface topography measurement instrument, wherein the first image corresponds to a first field of view of the mechanical part for the surface topography measurement instrument; ii) rotating the mechanical part with respect to a rotation axis provided by a rotatable mount used to secure the mechanical part to provide a second field of view of the mechanical part for the surface topography measurement instrument, wherein the first and second fields of view overlap to provide image information about a common region of the mechanical part; iii) acquiring data for a second areal surface topography image using the surface topography measurement instrument, wherein the second image corresponds to the second field of view; and iv) processing the data from the images.
