Visualization of curvature plots and evaluation of fairness: an analysis of the effect of 'scaling'

Changing the aspect-ratio (scale) of a graphical plot significantly affects the "messages" getting across to a viewer. This is true also for curvature plots and other graphs currently used in Curve & Surface Modeling to evaluate fairness. In particular, the sharp corners appearing in such graphs, employed as local.fairness indicators by current practices, are significantly affected by nonuniform scaling. A detailed study of this phenomenon is presented offering specific guidelines for correctly "reading" curvature plots. Kevwords: Spline; Curve; Slope of curvature; Aspect-ratio; Derivative of curvature; Aesthetic design; Corners; Scaling; Smoothing; Vehicle styling