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 |
|---|---|---|---|---|---|---|
| Area | ocx | ocx:Quantity_T | opt. | [0, 1] | False | The surface area computed by the sending application. Used to verify geometry reconstruction by allowing the receiving application to compare the source value with the reconstructed value. |
| 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. |
| Description | ocx | xs:string | opt. | [0, 1] | False | Contains a description of the component its parent represents. The description is stored as a string. You can use this element for whatever purposes you require. This element can be used inside many OCX XML elements but is optional. |
| FaceBoundaryCurve | ocx | ocx:Contour3D_T | opt. | [0, 1] | False | A collection of 3D curves making up a closed boundary. To be used whenever the surface need to be bounded. |
| 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 sizem=+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 sizem=+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 | Restriction of type 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. |