Parametric Surface - Examples

Examples

  • The simplest type of parametric surfaces is given by the graphs of functions of two variables:
  • Surfaces of revolution give another important class of surfaces that can be easily parametrized. If the graph z = f(x), a ≤ x ≤ b is rotated about the z-axis then the resulting surface has a parametrization
 \vec r(u,\phi) = (u\cos\phi, u\sin\phi, f(u)),
\quad a\leq u\leq b, 0\leq\phi < 2\pi.
  • The straight circular cylinder of radius R about x-axis has the following parametric representation:
  • Using the spherical coordinates, the unit sphere can be parameterized by
This parametrization breaks down at the north and south poles where the azimuth angle θ is not determined uniquely.

The same surface admits many different parametrizations. For example, the coordinate z-plane can be parametrized as

for any constants a, b, c, d such that ad − bc ≠ 0, i.e. the matrix is invertible.

Read more about this topic:  Parametric Surface

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