5.1.9 Sor

Another version of a surface of revolution is the sor object. Its syntax is:
SOR:
  sor { NUM_POINTS, POINT_LIST [open] [SOR_MODIFIERS] }

SOR_MODIFIERS:
  [sturm [BOOL]] & [UV_MAPPING] & [OBJECT_MODIFIERS]
See also:

This object is obtained by rotating the area between $ y$-axes and the cubic polynomial from $ P_{k}$ to $ P_{k+1}$ through the points $ P_{k-1}$, $ P_k$, $ P_{k+1}$ and $ P_{k+2}$ around the $ y$-axes. The point $ P_0$ and $ P_n$ are thus only control points.

See also:

Advantage of sor over lathe is that the intersection test for sor needs to solve a cubic polynomial whereas that for lathe needs to solve a polynomial of degree 6, which means quite a lot more work.

Andreas Kriegl 2003-07-23