[Sussex] Help! Equation for a surface wantted.

[Mark Harrison (Groups)]

On Thu, 2005-10-20 at 20:10 +0100, Steve Dobson wrote:
> 
> The surface I want is very similar to a torus, but the radius of
> the circle changes linearly between two values.

Steve,

Too many circles to work out what you're after:

- Possibility 1, you are looking for something like a circle extruded
round an ellipse. (Think a normal doughnut that you are pulling apart
from opposite "corners".)

- Possibility 2, you are looking for something like a doughnut, but at
some points of the doughnut the dough is thicker than others, however,
cutting through the dough at any point always gives a circle.

- Possibility 3, you are looking for something like a doughnut, but
instead of the dough bit being a circle, the dough bit is an ellipse, so
you are effectively extruding an ellipse round a circle.

Which one?

M.