Figure 8
(a) Description of the surface of the domain U0 using spherical coordinates (θ, φ). (b) An example of a domain for which no origin can be found to describe the surface by the function R(θ, φ) which is limited to a single value of r for every (θ, φ). In this case, three values of r are necessary to describe the surface at the (θ, φ) illustrated. Note that the origin may be located anywhere inside the domain. As a consequence, certain concave features, depending upon their severity, cannot be represented using spherical coordinates, e.g. those features approaching the shape of a `donut hole'. (c) Graphical definitions of , θ and φ. |