Non-uniform rational basis surface definition defined by a net (grid) of polynomial basis functions in U and V direction. NURBSSurface has the following child elements:
| Child | Namespace | Type | Use | Cardinality | Choice | Description |
|---|---|---|---|---|---|---|
| ControlPtList | ocx | ocx:ControlPtList_T | req. | [1, ∞] | False | List of control points (X,Y,Z) and their optional weights. The array length N=degree+1. A minimum of 2 control points is necessary to define a curve. |
| U_NURBSproperties | ocx | ocx:NURBSProperties_T | req. | [1, 1] | False | Properties of the basis function in V direction. |
| UknotVector | ocx | ocx:KnotVector_T | req. | [1, 1] | False | The knot-vector in U direction is a list of size m=+n-1 knots where p is the polynomial basis degree and n is the number of control points. The knot vector consist of a non-decreasing sequence of values. Knot multiplicities can be included. A knot multiplicity means that a knot value can be repeated up to p+1 times. |
| V_NURBSproperties | ocx | ocx:NURBSProperties_T | req. | [1, 1] | False | Properties of the basis function in V direction. |
| VknotVector | ocx | ocx:KnotVector_T | req. | [1, 1] | False | The knot-vector in V direction is a list of size m=+n-1 knots where p is the polynomial basis degree and n is the number of control points. The knot vector consist of a non-decreasing sequence of values. Knot multiplicities can be included. A knot multiplicity means that a knot value can be repeated up to p+1 times. |
NURBSSurface has the following attributes:
| Attribute | Namespace | Type | Use | Default | Fixed | Description |
|---|---|---|---|---|---|---|
| GUIDRef | ocx | ocx:guid | opt. | A globally unique ID referring to an entity in the authoring application. The sending application creates and holds the GUID. Used to establish a unique reference to an entity persistent between applications. | ||
| name | ocx | xs:string | opt. | An optional descriptive or display name. | ||
| id | ocx | xs:ID | req. | An identifier for an element unique within the scope of the XML file. Each id must be unique within a document. The attribute uses the standard XML 1.0 ID type as defined in the XML Schema specification. This attribute is required in many OCX XML elements and an application should generate them automatically. |