In some cases when working with Edit Curves, users may find that the defined U parameters for control points do not intuitively align with adjacent sections due to how the control points were first added or altered. In this case, the curve may be reparametrized by arc length which redistributes the U locations evenly between fixed control points. For example, with the simple pentagon shape in the tutorial the first and last control points are the only fixed locations (U = 0,1) so reparametrizing the curve would result in a new U distribution of 0.2 units each (1/5) assuming all arc lengths are equal. However, in the event that a control point should be aligned with a specific location on adjacent cross-sections, as with the left side of the pentagon at U = 0.5, the U value may be fixed by clicking the Fix U button for that control point. This prevents the reparameterization from moving that U location and will evenly distribute any free U points along the curve. Reparametrizing Edit Curves by arc length is an excellent way of distributing interpolated segments so that the model surface remains smooth.