The role of workpiece geometry in manufacture is shown below in Figure 6.1 as a subset of the block diagram drawn in the rst chapter (Figure 1.1).

The present chapter shows that there is a two-way interaction between the surface and the manufacturing process. The rst interaction is concerned with the nature of the geometric characteristics produced on the surface by the manufacturing process. This is considered in some detail in Sections 6.2 through 6.6. Physical characteristics are examined in Sections 6.11 and 6.12. The other interaction concerns ways in which the surface roughness and form can be used to detect changes in the process and also; in some cases, the machine tool. Some ways of doing this are examined in Section 6.8. It is shown that the Fourier kernel and its derivatives, such as the Wigner function, can be used to a great effect.