4.18.6 NurbsSurface class

4.18.6 NurbsSurface class

class NurbsSurface: This class stores the data of a NURBS surface. NurbsSurface objects are returned when the value of a nurbsSurface attribute is requested.

The class has the following data members:

udegree: Degree in u direction.

vdegree: Degree in v direction.

uform

Form attribute for the u direction. The attribute can have one of the following values:

Value	Meaning
`0`	Open
`1`	Closed
`2`	Periodic

vform: Form attribute for the v direction (see above).

isrational: This attribute is True if the surface contains a rational component. In this case, the control vertices are given as 4-tuples, otherwise as 3-tuples.

uknots: This is a list of floats containing the knot values for the u direction.

vknots: This is a list of floats containing the knot values for the v direction.

cvs: A list of control vertices. Each vertex is given either as a 3-tuple or 4-tuple of floats.