---
name: "SoIndexedNurbsCurve"
section: "3iv"
platform: "linux"
package: "inventor-doc"
version: "2.1.6+ds-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/SoIndexedNurbsCurve/3iv"
---

# SoIndexedNurbsCurve(3iv)

indexed NURBS curve shape node

## NAME

SoIndexedNurbsCurve — indexed NURBS curve shape node

## INHERITS FROM

SoBase \> SoFieldContainer \> SoNode \> SoShape \> SoIndexedNurbsCurve

## SYNOPSIS

**#include \<Inventor/nodes/SoIndexedNurbsCurve.h\>**

Fields from class SoIndexedNurbsCurve:

**SoSFInt32**	**numControlPoints**\
 **SoMFInt32**	**coordIndex**\
 **SoMFFloat**	**knotVector**

Methods from class SoIndexedNurbsCurve:

	**SoIndexedNurbsCurve()**\
 **static SoType**	**getClassTypeId()**

Methods from class SoNode:

**void**	**setOverride(SbBool state)**\
 **SbBool**	**isOverride() const**\
 **SoNode \***	**copy(SbBool copyConnections = FALSE) const**\
 **virtual SbBool**	**affectsState() const**\
 **static SoNode \***	**getByName(const SbName &name)**\
 **static int**	**getByName(const SbName &name, SoNodeList &list)**

Methods from class SoFieldContainer:

**void**	**setToDefaults()**\
 **SbBool**	**hasDefaultValues() const**\
 **SbBool**	**fieldsAreEqual(const SoFieldContainer \*fc) const**\
 **void**	**copyFieldValues(const SoFieldContainer \*fc, SbBool copyConnections = FALSE)**\
 **SbBool**	**set(const char \*fieldDataString)**\
 **void**	**get(SbString &fieldDataString)**\
 **virtual int**	**getFields(SoFieldList &resultList) const**\
 **virtual SoField \***	**getField(const SbName &fieldName) const**\
 **SbBool**	**getFieldName(const SoField \*field, SbName &fieldName) const**\
 **SbBool**	**isNotifyEnabled() const**\
 **SbBool**	**enableNotify(SbBool flag)**

Methods from class SoBase:

**void**	**ref()**\
 **void**	**unref() const**\
 **void**	**unrefNoDelete() const**\
 **void**	**touch()**\
 **virtual SoType**	**getTypeId() const**\
 **SbBool**	**isOfType(SoType type) const**\
 **virtual void**	**setName(const SbName &name)**\
 **virtual SbName**	**getName() const**

## DESCRIPTION

**This class represents a NURBS curve based on the knot vector and the control points that you specify. The knotVector** field specifies a floating-point array of values; the values are the coordinates of the knot points in the curve, and you must enter them in non-decreasing order. The **numControlPoints** field specifies the number of control points the curve will have and will use the current coordinates that are indexed from the **coordIndex** field.

You can get a curve of minimum order (2) by specifying two more knots than control points and having at least two control points. This curve would be a set of line segments connecting the control points together.

You can get a curve of maximum order (8) by specifying 8 more knots than control points and having at least 8 control points. In this curve, each control point would have influence on a larger portion of the curve than with curves of lesser order.

The control points of the curve are transformed by the current transformation matrix. The curve is drawn with the current lighting model and drawing style (drawing style **FILLED** is treated as **LINES**). The coordinates, normals, and texture coordinates of a NURBS curve are generated, so you cannot bind explicit normals or texture coordinates to a NURBS curve.

The approximation of the curve by line segments is affected by the current complexity value.

## FIELDS

**SoSFInt32**	**numControlPoints**\
 Number of control points for the curve.

**SoMFInt32**	**coordIndex**\
 Coordinate indices for the control points.

**SoMFFloat**	**knotVector**\
 The knot vector for the curve. Values must be in non-decreasing order.

## METHODS

	**SoIndexedNurbsCurve()**\
 Creates an indexed NURBS curve node with default settings.

**static SoType**	**getClassTypeId()**\
 Returns type identifier for this class.

## ACTION BEHAVIOR

**SoGLRenderAction**\
 Draws the curve based on the current coordinates, material, and so on.

**SoRayPickAction**\
 Picks the curve based on the current coordinates and transformation.

**SoGetBoundingBoxAction**\
 Computes the bounding box that encloses all control points of the curve with the current transformation applied to them. Sets the center to the average of the control points.

**SoCallbackAction**\
 If any line segment callbacks are registered with the action, they will be invoked for each successive segment approximating the curve.

## FILE FORMAT/DEFAULTS

```
IndexedNurbsCurve {
numControlPoints	0
coordIndex	0
knotVector	0
}
```

## SEE ALSO

**SoNurbsCurve, SoIndexedNurbsSurface**