EZ_Tube - render a tube around a curve
void EZ_Tube(float *data, int npts, int nsides)
Specifies an array of floats. The array defines a curve and the
radius at each sample point, in the format:
data has to be a static array.
npts Specifies the number of points in data.
nsides Specifies the number of desired number of sides along the
renders a tube around the given curve.