The SoNurbsCurve class is a node for representing smooth curves. More...

#include <Inventor/nodes/SoNurbsCurve.h>

Inheritance diagram for SoNurbsCurve:

Public Member Functions
	SoNurbsCurve (void)

virtual void	getBoundingBox (SoGetBoundingBoxAction *action)

virtual void	getPrimitiveCount (SoGetPrimitiveCountAction *action)

virtual SoType	getTypeId (void) const

virtual void	GLRender (SoGLRenderAction *action)

virtual void	rayPick (SoRayPickAction *action)

void	sendPrimitive (SoAction , SoPrimitiveVertex )

Public Member Functions inherited from SoShape
virtual SbBool	affectsState (void) const

virtual void	callback (SoCallbackAction *action)

const SoBoundingBoxCache *	getBoundingBoxCache (void) const

virtual void	notify (SoNotList *nl)

Public Member Functions inherited from SoNode
virtual SoNode *	addToCopyDict (void) const

virtual void	audioRender (SoAudioRenderAction *action)

virtual SoNode *	copy (SbBool copyconnections=FALSE) const

virtual void	copyContents (const SoFieldContainer *from, SbBool copyconnections)

virtual SoFieldContainer *	copyThroughConnection (void) const

virtual void	doAction (SoAction *action)

virtual SoChildList *	getChildren (void) const

virtual void	getMatrix (SoGetMatrixAction *action)

SbUniqueId	getNodeId (void) const

NodeType	getNodeType (void) const

virtual void	GLRenderBelowPath (SoGLRenderAction *action)

virtual void	GLRenderInPath (SoGLRenderAction *action)

virtual void	GLRenderOffPath (SoGLRenderAction *action)

virtual void	grabEventsCleanup (void)

virtual void	grabEventsSetup (void)

virtual void	handleEvent (SoHandleEventAction *action)

SbBool	isOverride (void) const

virtual void	pick (SoPickAction *action)

virtual void	search (SoSearchAction *action)

void	setNodeType (const NodeType type)

void	setOverride (const SbBool state)

virtual void	startNotify (void)

virtual void	write (SoWriteAction *action)

virtual void	writeInstance (SoOutput *out)

Public Member Functions inherited from SoFieldContainer
virtual void	addWriteReference (SoOutput *out, SbBool isfromfield=FALSE)

void	copyFieldValues (const SoFieldContainer *container, SbBool copyconnections=FALSE)

SbBool	enableNotify (const SbBool flag)

SbBool	fieldsAreEqual (const SoFieldContainer *container) const

void	get (SbString &fielddata)

void	get (SbString &fielddata, SoOutput *out)

virtual int	getAllFields (SoFieldList &l) const

virtual SoField *	getEventIn (const SbName &name) const

virtual SoField *	getEventOut (const SbName &name) const

virtual SoField *	getField (const SbName &name) const

SbBool	getFieldName (const SoField *const field, SbName &name) const

virtual int	getFields (SoFieldList &l) const

virtual void	getFieldsMemorySize (size_t &managed, size_t &unmanaged) const

SbBool	getIsBuiltIn (void) const

void *	getUserData (void) const

SbBool	hasDefaultValues (void) const

SbBool	isNotifyEnabled (void) const

SbBool	set (const char *const fielddata)

SbBool	set (const char fielddata, SoInput input)

void	setToDefaults (void)

void	setUserData (void *userdata) const

virtual SbBool	validateNewFieldValue (SoField field, void newval)

Public Member Functions inherited from SoBase
void	addAuditor (void *const auditor, const SoNotRec::Type type)

void	assertAlive (void) const

const SoAuditorList &	getAuditors (void) const

virtual SbName	getName (void) const

int32_t	getRefCount (void) const

SbBool	isOfType (SoType type) const
	Returns `TRUE` if the type of this object is either of the same type or inherited from type.

void	ref (void) const

void	removeAuditor (void *const auditor, const SoNotRec::Type type)

virtual void	setName (const SbName &newname)

SbBool	shouldWrite (void)

void	touch (void)

void	unref (void) const

void	unrefNoDelete (void) const

Static Public Member Functions
static SoType	getClassTypeId (void)

static void	initClass (void)

Static Public Member Functions inherited from SoShape
static SoType	getClassTypeId (void)

static float	getDecimatedComplexity (SoState *state, float complexity)

static void	getScreenSize (SoState *const state, const SbBox3f &boundingbox, SbVec2s &rectsize)

static void	initClass (void)
	Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

Static Public Member Functions inherited from SoNode
static void	audioRenderS (SoAction action, SoNode node)

static void	callbackS (SoAction action, SoNode node)

static int	getActionMethodIndex (const SoType type)

static void	getBoundingBoxS (SoAction action, SoNode node)

static SoNode *	getByName (const SbName &name)

static int	getByName (const SbName &name, SoNodeList &l)

static SoType	getClassTypeId (void)

static uint32_t	getCompatibilityTypes (const SoType &nodetype)

static void	getMatrixS (SoAction action, SoNode node)

static SbUniqueId	getNextNodeId (void)

static void	getPrimitiveCountS (SoAction action, SoNode node)

static void	GLRenderS (SoAction action, SoNode node)

static void	handleEventS (SoAction action, SoNode node)

static void	initClass (void)
	Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

static void	initClasses (void)

static void	pickS (SoAction action, SoNode node)

static void	rayPickS (SoAction action, SoNode node)

static void	searchS (SoAction action, SoNode node)

static void	writeS (SoAction action, SoNode node)

Static Public Member Functions inherited from SoFieldContainer
static void	addCopy (const SoFieldContainer orig, const SoFieldContainer copy)

static SoFieldContainer *	checkCopy (const SoFieldContainer *orig)

static void	cleanupClass (void)

static void	copyDone (void)

static SoFieldContainer *	findCopy (const SoFieldContainer *orig, const SbBool copyconnections)

static SoType	getClassTypeId (void)
	This static method returns the SoType object associated with objects of this class.

static void	initClass (void)
	Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

static void	initCopyDict (void)

Static Public Member Functions inherited from SoBase
static void	addName (SoBase const base, const char const name)

static SbBool	connectRoute (SoInput *input, const SbName &fromnodename, const SbName &fromfieldname, const SbName &tonodename, const SbName &tofieldname)

static void	decrementCurrentWriteCounter (void)

static SoType	getClassTypeId (void)
	This static method returns the SoType object associated with objects of this class.

static SoBase *	getNamedBase (const SbName &name, SoType type)

static int	getNamedBases (const SbName &name, SoBaseList &baselist, SoType type)

static SbBool	getTraceRefs (void)

static void	incrementCurrentWriteCounter (void)

static void	initClass (void)
	Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

static SbBool	read (SoInput input, SoBase &base, SoType expectedtype)

static SbBool	readRoute (SoInput *input)

static void	removeName (SoBase const base, const char const name)

static void	setInstancePrefix (const SbString &c)

static void	setTraceRefs (SbBool trace)

Public Attributes
SoMFFloat	knotVector

SoSFInt32	numControlPoints

Protected Member Functions
virtual	~SoNurbsCurve ()

virtual void	computeBBox (SoAction *action, SbBox3f &box, SbVec3f &center)

virtual SoDetail *	createLineSegmentDetail (SoRayPickAction action, const SoPrimitiveVertex v1, const SoPrimitiveVertex v2, SoPickedPoint pp)

virtual void	generatePrimitives (SoAction *action)

virtual const SoFieldData *	getFieldData (void) const

Protected Member Functions inherited from SoShape
	SoShape (void)

virtual	~SoShape ()

void	beginShape (SoAction const action, const TriangleShape shapetype, SoDetail const detail=NULL)

void	beginSolidShape (SoGLRenderAction *action)

void	computeObjectSpaceRay (SoRayPickAction *const action)

void	computeObjectSpaceRay (SoRayPickAction *const action, const SbMatrix &matrix)

virtual SoDetail *	createPointDetail (SoRayPickAction action, const SoPrimitiveVertex v, SoPickedPoint *pp)

virtual SoDetail *	createTriangleDetail (SoRayPickAction action, const SoPrimitiveVertex v1, const SoPrimitiveVertex v2, const SoPrimitiveVertex v3, SoPickedPoint *pp)

void	endShape (void)

void	endSolidShape (SoGLRenderAction *action)

void	finishVertexArray (SoGLRenderAction *action, const SbBool vbo, const SbBool normpervertex, const SbBool texpervertex, const SbBool colorpervertex)

void	generateVertex (SoPrimitiveVertex const pv, const SbVec3f &point, const SbBool useTexFunc, const SoMultiTextureCoordinateElement const tce, const float s, const float t, const float r, const SbVec3f &normal)

void	generateVertex (SoPrimitiveVertex const pv, const SbVec3f &point, const SbBool useTexFunc, const SoMultiTextureCoordinateElement const tce, const float s, const float t, const SbVec3f &normal)

float	getComplexityValue (SoAction *action)

void	GLRenderBoundingBox (SoGLRenderAction *action)

void	invokeLineSegmentCallbacks (SoAction const action, const SoPrimitiveVertex const v1, const SoPrimitiveVertex *const v2)

void	invokePointCallbacks (SoAction const action, const SoPrimitiveVertex const v)

void	invokeTriangleCallbacks (SoAction const action, const SoPrimitiveVertex const v1, const SoPrimitiveVertex const v2, const SoPrimitiveVertex const v3)

void	shapeVertex (const SoPrimitiveVertex *const v)

virtual SbBool	shouldGLRender (SoGLRenderAction *action)

SbBool	shouldPrimitiveCount (SoGetPrimitiveCountAction *action)

SbBool	shouldRayPick (SoRayPickAction *const action)

SbBool	startVertexArray (SoGLRenderAction action, const SoCoordinateElement coords, const SbVec3f *pervertexnormals, const SbBool texpervertex, const SbBool colorpervertex)

Protected Member Functions inherited from SoNode
	SoNode (void)

virtual	~SoNode ()

virtual SbBool	readInstance (SoInput *in, unsigned short flags)

Protected Member Functions inherited from SoFieldContainer
	SoFieldContainer (void)

virtual	~SoFieldContainer ()

Protected Member Functions inherited from SoBase
	SoBase (void)

virtual	~SoBase ()

virtual SoNotRec	createNotRec (void)

virtual void	destroy (void)

virtual const char *	getFileFormatName (void) const

SbBool	hasMultipleWriteRefs (void) const

void	writeFooter (SoOutput *out) const

SbBool	writeHeader (SoOutput *out, SbBool isgroup, SbBool isengine) const

Static Protected Member Functions
static const SoFieldData **	getFieldDataPtr (void)

Static Protected Member Functions inherited from SoShape
static const SoFieldData **	getFieldDataPtr (void)

Static Protected Member Functions inherited from SoNode
static const SoFieldData **	getFieldDataPtr (void)

static int	getNextActionMethodIndex (void)

static void	incNextActionMethodIndex (void)

static void	setCompatibilityTypes (const SoType &nodetype, const uint32_t bitmask)

static void	setNextActionMethodIndex (int index)

Static Protected Member Functions inherited from SoBase
static uint32_t	getCurrentWriteCounter (void)

static void	staticDataLock (void)

static void	staticDataUnlock (void)

Additional Inherited Members
Public Types inherited from SoShape
enum	TriangleShape { TRIANGLE_STRIP , TRIANGLE_FAN , TRIANGLES , POLYGON , QUADS , QUAD_STRIP , POINTS , LINES , LINE_STRIP }

Public Types inherited from SoNode
enum	NodeType { INVENTOR = 0x0000 , VRML1 = 0x0001 , VRML2 = 0x0002 , INVENTOR_1 = 0x0004 , INVENTOR_2_0 = 0x0008 , INVENTOR_2_1 = 0x0010 , INVENTOR_2_5 = 0x0020 , INVENTOR_2_6 = 0x0040 , COIN_1_0 = 0x0080 , COIN_2_0 = 0x0100 , EXTENSION = 0x0200 , COIN_2_2 = 0x0400 , COIN_2_3 = 0x0800 , COIN_2_4 = 0x1000 , INVENTOR_5_0 = 0x2000 , COIN_2_5 = 0x4000 , COIN_3_0 = 0x8000 , INVENTOR_6_0 = 0x10000 , COIN_4_0 = 0x20000 }

Protected Types inherited from SoBase
enum	BaseFlags { IS_ENGINE = 0x01 , IS_GROUP = 0x02 }

Protected Attributes inherited from SoNode
SbUniqueId	uniqueId

Protected Attributes inherited from SoFieldContainer
SbBool	isBuiltIn

Static Protected Attributes inherited from SoNode
static int	nextActionMethodIndex = 0

static SbUniqueId	nextUniqueId = 1

Detailed Description

The SoNurbsCurve class is a node for representing smooth curves.

A general explanation of NURBS is beyond the scope of the Coin documentation. For detailed information, refer to the specialized literature on the topic (for example "An Introduction to NURBS: With Historical Perspective" by David F. Rogers). A basic overview of curve and surface rendering using NURBS can be found in chapter 8 of "The Inventor Mentor".

Note that knot values should be specified as [0, 1, 2,..., a] rather than [0, 1/a, 2/a,..., 1] to avoid tessellation errors due to floating point precision problems. (Even if the rendered curve looks correct, such issues might surface when e.g. doing picking, since the tessellated representation used internally is not the same as the one you see rendered by OpenGL on-screen.)

Each control point has a weight that changes the shape of its basis function. Weight is analogous to having magnets pulling on the curve. Coordinate3 sets control points to have an equal weight of 1.0 (nonrational). Use Coordinate4 to specify x, y, z and weight values (rational).

A small usage example (drawing a circle using a rational curve):

#Inventor V2.1 ascii
 
Coordinate4 {
   point [
     0.0 -5.0     0.0 1.0,
     2.5 -2.5     0.0 0.5,
     2.5 -0.66987 0.0 1.0,
     0.0  1.94013 0.0 0.5,
    -2.5 -0.66987 0.0 1.0,
    -2.5 -2.5     0.0 0.5,
     0.0 -5.0     0.0 1.0
   ]
}
 
NurbsCurve {
   numControlPoints 7
   knotVector [ 0, 0, 0, 1, 1, 2, 2, 3, 3, 3 ]
}
 
# debug: show all the control points
BaseColor { rgb 1 1 0 }
DrawStyle { pointSize 3 }
PointSet { numPoints 7 }

Rendering of Example Scenegraph

FILE FORMAT/DEFAULTS:

NurbsCurve {
    numControlPoints 0
    knotVector 0
}

Constructor & Destructor Documentation

◆ SoNurbsCurve()

SoNurbsCurve::SoNurbsCurve ( void )

Constructor.

◆ ~SoNurbsCurve()

SoNurbsCurve::~SoNurbsCurve ( )

protectedvirtual

Destructor.

Member Function Documentation

◆ computeBBox()

void SoNurbsCurve::computeBBox	(	SoAction *	action,
		SbBox3f &	box,
		SbVec3f &	center )

protectedvirtual

Calculates the bounding box of all control points, and sets the center to the average of these points.

Implements SoShape.

◆ createLineSegmentDetail()

SoDetail * SoNurbsCurve::createLineSegmentDetail	(	SoRayPickAction *	action,
		const SoPrimitiveVertex *	v1,
		const SoPrimitiveVertex *	v2,
		SoPickedPoint *	pp )

protectedvirtual

Will create line detail for a SoPickedPoint. This method will only be called internally, when generatePrimitives() is used for picking (SoShape::rayPick() is not overridden).

This method returns NULL in Open Inventor, and subclasses will need to override this method to create details for a SoPickedPoint.

This is not necessary with Coin. Of course, if you choose to override it, it will work in the same way as Open Inventor.

For this to work, you must supply a face or line detail when generating primitives. If you supply NULL for the detail argument in SoShape::beginShape(), you'll have to override this method.

Reimplemented from SoShape.

◆ generatePrimitives()

void SoNurbsCurve::generatePrimitives ( SoAction * action )

protectedvirtual

The method implements action behavior for shape nodes for SoCallbackAction. It is invoked from SoShape::callback(). (Subclasses should not override SoNode::callback().)

The subclass implementations uses the convenience methods SoShape::beginShape(), SoShape::shapeVertex(), and SoShape::endShape(), with SoDetail instances, to pass the primitives making up the shape back to the caller.

Implements SoShape.

◆ getBoundingBox()

void SoNurbsCurve::getBoundingBox ( SoGetBoundingBoxAction * action )

virtual

Redefined to notify open caches that this shape contains lines.

Reimplemented from SoShape.

◆ getClassTypeId()

SoType SoNurbsCurve::getClassTypeId ( void )

static

This static method returns the SoType object associated with objects of this class.

◆ getFieldData()

const SoFieldData * SoNurbsCurve::getFieldData ( void ) const

protectedvirtual

Returns a pointer to the class-wide field data storage object for this instance. If no fields are present, returns NULL.

Reimplemented from SoShape.

◆ getFieldDataPtr()

const SoFieldData ** SoNurbsCurve::getFieldDataPtr ( void )

staticprotected

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

Returns the SoFieldData class which holds information about fields in this node.

◆ getPrimitiveCount()

void SoNurbsCurve::getPrimitiveCount ( SoGetPrimitiveCountAction * action )

virtual

Action method for the SoGetPrimitiveCountAction.

Calculates the number of triangle, line segment and point primitives for the node and adds these to the counters of the action.

Nodes influencing how geometry nodes calculate their primitive count also override this method to change the relevant state variables.

Reimplemented from SoShape.

◆ getTypeId()

SoType SoNurbsCurve::getTypeId ( void ) const

virtual

Returns the type identification of an object derived from a class inheriting SoBase. This is used for runtime type checking and "downward" casting.

Reimplemented from SoShape.

◆ GLRender()

void SoNurbsCurve::GLRender ( SoGLRenderAction * action )

virtual

Action method for the SoGLRenderAction.

This is called during rendering traversals. Nodes influencing the rendering state in any way or want to throw geometry primitives at OpenGL override this method.

Reimplemented from SoShape.

◆ initClass()

void SoNurbsCurve::initClass ( void )

static

◆ rayPick()

void SoNurbsCurve::rayPick ( SoRayPickAction * action )

virtual

Calculates picked point based on primitives generated by subclasses.

Reimplemented from SoShape.

◆ sendPrimitive()

void SoNurbsCurve::sendPrimitive	(	SoAction *	a,
		SoPrimitiveVertex *	p )

This method is part of the original SGI Inventor API, but not implemented in Coin, as it looks like a method that should probably have been private in Open Inventor.

Member Data Documentation

◆ knotVector

SoMFFloat SoNurbsCurve::knotVector

The knot vector.

Values should be specified as [0, 1, 2,..., a] rather than [0, 1/a, 2/a,..., 1] to avoid tessellation errors due to floating point precision problems.

◆ numControlPoints

SoSFInt32 SoNurbsCurve::numControlPoints

Number of control points to use in this NURBS curve.

The documentation for this class was generated from the following files:

SoNurbsCurve.h
SoNurbsCurve.cpp

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Static Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SoNurbsCurve()

◆ ~SoNurbsCurve()

Member Function Documentation

◆ computeBBox()

◆ createLineSegmentDetail()

◆ generatePrimitives()

◆ getBoundingBox()

◆ getClassTypeId()

◆ getFieldData()

◆ getFieldDataPtr()

◆ getPrimitiveCount()

◆ getTypeId()

◆ GLRender()

◆ initClass()

◆ rayPick()

◆ sendPrimitive()

Member Data Documentation

◆ knotVector

◆ numControlPoints