Linear

This is probably the easiest path to understand and use, simply specify the start and the end of the path and that is it.

Creating the Linear path

Constructors 
Linear(PVector start, PVector end, int nbrSlices)
Linear(PVector start, PVector end, int nbrSlices, PathOrthogonal ortho)
Parameter Comments 
start, end
 PVectors defining the start and the end of the shape 
nbrSlices
 the number of slices along the length of the path 
ortho
 this is used to reduce the amount of twist along the length of the shape. If this parameter is omitted Shapes3D will try and find the best value. Alternatively you can specify 1 of 4 possible values - S3D.ORTHO_X, S3D.ORTHO_Y, S3D.ORTHO_Z or S3D.ORTHO_A.