NurbsCurveList

Object Hierarchy | Related C++ Class: NurbsCurveList

NurbsCurveList

A NurbsCurveList is a kind of Geometry and is a collection of NurbsCurve objects. You can navigate the
NurbsCurveList using the generic objects such as Point and Sample or you
can navigate using objects that are specific to the NurbsCurveList
such as ControlPoint and NurbsSample. A nurbs curve is defined as
follows; surface can be defined similarly in 2 dimensions:

degree: k, order: k+1, Number of Control Points: n, Knot sequence =
t(0), t(1)... t(k)... t(n)... t(n+k+1)

...where the knot sequence is non-decreasing which means t(0) <=
t(1) <= ..... <= t(n)... <= t(n+k+1)

The above is a general definition for a nurbs curve and IGES
standard supports this definition. However in most industrial
design systems, people put some constraints on the knot sequence:
for a degree k curve, the first k+1 knots and the last k+1 knots
are equal, e.g. t(0) = t(1) = ... = t(k) and t(n+1) = t(n+2) =... =
t(n+k+1). This ensures the curve passes the start ControlPoint and
end ControlPoint which is a nice property to control the final
shape of nurbs curve. For now we only support this constrained
version of IGES format as we expect most design systems are using
this format.

Application | Cache | Categories | Closed |

Clusters | ControlPoints | Curves | Facets |

FullName | Help | ICEAttributes | Length |

Name | NestedObjects | Origin | OriginPath |

Parent | Points | Samples | Segments |

Triangles | Type | ||

set oObject = Application.ActiveProject.ActiveScene.Root.AddGeometry("Arc","NurbsCurve") set oNurbsCurveList = oObject.ActivePrimitive.Geometry |