A better indication of the surface is normally obtained using contour
maps. There are different types of contour maps. The simplest
contouring method is to intersect the surface with a family of
user-defined non-uniformly spaced parallel planes
[22,95] (see Fig. 5.1). Using
contour maps, maxima,
minima and saddle points of the height
of the surface can be
identified. Contouring with planes is, for example, employed in ship hull
and aircraft fuselage design. More complex contouring methods involve
intersections with a series of co-axial cylinders or cones of
non-uniformly spaced radii. Propeller and turbine blades are normally
contoured using such methods. The intersection methods of Chap.
5 need to be invoked to perform robust contouring.