In our last video, “Roughness and Waviness,” we looked at how to separate longer wavelength “waviness” from short-wavelength “roughness.” In “Bandpass Waviness” we go a step further and also separate waviness from the long-wavelength “form” shapes. Making this distinction lets us target the waviness features that could matter most to you. For example, if you are trying to create a sealing surface, controlling the waviness-related lumps or bumps may be your biggest challenge. One surprising upshot of controlling these features separately: the added controls may actually let you loosen tolerances on the long wavelength form as a result.