GenCyl

This program generates a cartesian mesh [x,y,z] from a 3D curve, and a vector of associated radii.

It takes four inputs, two of which are optional:
* P (3D curve) = 3xN matrix with each point of the curve given in correct order and columnwise.
* R (Radii) = 1xN vector with positive scalar corresponding to the radius at each point
- [opt] NBetween: defaults to 2. Can be used to smooth the variations of the radii on the mesh; the radii will automatically be interpolated if it is >2. It is equivalent to the length of the first parameter of 'cylinder' in Matlab.
- [opt] NArround: defaults to 20. Equivalent to the second parameter of 'cylinder' in Matlab.

Very fast computation of the mesh. Uses the 'cylinder' function of Matlab, as well as quaternions and spline interpolation.