SoNurbsCurve(3)

📦
version 4.0.10 · 4 versions
, in fedora 43, fedora 44

✨ NAME ✨

SoNurbsCurve(3) from Coin is here, bestie! The SoNurbsCurve class is a node for representing smooth curves. No cap, it's giving smooth curve energy. 💅

✨ SYNOPSIS ✨

#include <Inventor/nodes/SoNurbsCurve.h>

Inherits SoShape.

✨ Public Member Functions ✨

okay so here's the main character lineup:

  • virtual SoType getTypeId (void) const
  • SoNurbsCurve (void)
  • virtual void GLRender (SoGLRenderAction *action)
  • virtual void rayPick (SoRayPickAction *action)
  • virtual void getPrimitiveCount (SoGetPrimitiveCountAction *action)
  • virtual void getBoundingBox (SoGetBoundingBoxAction *action)
  • void sendPrimitive (SoAction *, SoPrimitiveVertex *)

✨ Public Member Functions inherited from SoShape ✨

these are the vibes you get from SoShape:

  • virtual SbBool affectsState (void) const
  • virtual void notify (SoNotList *nl)
  • virtual void callback (SoCallbackAction *action)
  • const SoBoundingBoxCache * getBoundingBoxCache (void) const

✨ Public Member Functions inherited from SoNode ✨

SoNode is the parent, so you get all of these too:

  • void setOverride (const SbBool state)
  • SbBool isOverride (void) const
  • void setNodeType (const NodeType type)
  • NodeType getNodeType (void) const
  • virtual SoNode * copy (SbBool copyconnections=FALSE) const
  • virtual void doAction (SoAction *action)
  • virtual void GLRenderBelowPath (SoGLRenderAction *action)
  • virtual void GLRenderInPath (SoGLRenderAction *action)
  • virtual void GLRenderOffPath (SoGLRenderAction *action)
  • virtual void getMatrix (SoGetMatrixAction *action)
  • virtual void handleEvent (SoHandleEventAction *action)
  • virtual void pick (SoPickAction *action)
  • virtual void search (SoSearchAction *action)
  • virtual void write (SoWriteAction *action)
  • virtual void audioRender (SoAudioRenderAction *action)
  • virtual void grabEventsSetup (void)
  • virtual void grabEventsCleanup (void)
  • virtual void startNotify (void)
  • SbUniqueId getNodeId (void) const
  • virtual SoChildList * getChildren (void) const
  • virtual void writeInstance (SoOutput *out)
  • virtual SoNode * addToCopyDict (void) const
  • virtual void copyContents (const SoFieldContainer *from, SbBool copyconnections)
  • virtual SoFieldContainer * copyThroughConnection (void) const

✨ Public Member Functions inherited from SoFieldContainer ✨

and SoFieldContainer brings even more to the party:

  • void setToDefaults (void)
  • SbBool hasDefaultValues (void) const
  • SbBool fieldsAreEqual (const SoFieldContainer *container) const
  • void copyFieldValues (const SoFieldContainer *container, SbBool copyconnections=FALSE)
  • SbBool set (const char *const fielddata)
  • void get (SbString &fielddata)
  • virtual int getFields (SoFieldList &l) const
  • virtual int getAllFields (SoFieldList &l) const
  • virtual SoField * getField (const SbName &name) const
  • virtual SoField * getEventIn (const SbName &name) const
  • virtual SoField * getEventOut (const SbName &name) const
  • SbBool getFieldName (const SoField *const field, SbName &name) const
  • SbBool enableNotify (const SbBool flag)
  • SbBool isNotifyEnabled (void) const
  • SbBool set (const char *fielddata, SoInput *input)
  • void get (SbString &fielddata, SoOutput *out)
  • virtual SbBool validateNewFieldValue (SoField *field, void *newval)
  • virtual void addWriteReference (SoOutput *out, SbBool isfromfield=FALSE)
  • SbBool getIsBuiltIn (void) const
  • virtual void getFieldsMemorySize (size_t &managed, size_t &unmanaged) const
  • void setUserData (void *userdata) const
  • void * getUserData (void) const

✨ Public Member Functions inherited from SoBase ✨

and SoBase? yeah, it's the root, so you get all these:

  • void ref (void) const
  • void unref (void) const
  • void unrefNoDelete (void) const
  • int32_t getRefCount (void) const
  • void touch (void)
  • SbBool isOfType (SoType type) const — returns TRUE if the type of this object is either of the same type or inherited from type. 💅
  • virtual SbName getName (void) const
  • virtual void setName (const SbName &newname)
  • void addAuditor (void *const auditor, const SoNotRec::Type type)
  • void removeAuditor (void *const auditor, const SoNotRec::Type type)
  • const SoAuditorList & getAuditors (void) const
  • SbBool shouldWrite (void)
  • void assertAlive (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 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 getScreenSize (SoState *const state, const SbBox3f &boundingbox, SbVec2s &rectsize)
  • static float getDecimatedComplexity (SoState *state, float complexity)

✨ Static Public Member Functions inherited from SoNode ✨

  • static uint32_t getCompatibilityTypes (const SoType &nodetype)
  • static SoType getClassTypeId (void)
  • static SoNode * getByName (const SbName &name)
  • static int getByName (const SbName &name, SoNodeList &l)
  • 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 SbUniqueId getNextNodeId (void)
  • static int getActionMethodIndex (const SoType type)
  • static void getBoundingBoxS (SoAction *action, SoNode *node)
  • static void GLRenderS (SoAction *action, SoNode *node)
  • static void callbackS (SoAction *action, SoNode *node)
  • static void getMatrixS (SoAction *action, SoNode *node)
  • static void handleEventS (SoAction *action, SoNode *node)
  • 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 void audioRenderS (SoAction *action, SoNode *node)
  • static void getPrimitiveCountS (SoAction *action, SoNode *node)

✨ Static Public Member Functions inherited from SoFieldContainer ✨

  • 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 SoType getClassTypeId (void) — this static method returns the SoType object associated with objects of this class. 💅
  • static void cleanupClass (void)
  • static void initCopyDict (void)
  • static void addCopy (const SoFieldContainer *orig, const SoFieldContainer *copy)
  • static SoFieldContainer * checkCopy (const SoFieldContainer *orig)
  • static SoFieldContainer * findCopy (const SoFieldContainer *orig, const SbBool copyconnections)
  • static void copyDone (void)

✨ Static Public Member Functions inherited from SoBase ✨

  • 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 SoType getClassTypeId (void) — this static method returns the SoType object associated with objects of this class. 💅
  • static void addName (SoBase *const base, const char *const name)
  • static void removeName (SoBase *const base, const char *const name)
  • static void incrementCurrentWriteCounter (void)
  • static void decrementCurrentWriteCounter (void)
  • static SoBase * getNamedBase (const SbName &name, SoType type)
  • static int getNamedBases (const SbName &name, SoBaseList &baselist, SoType type)
  • static SbBool read (SoInput *input, SoBase *&base, SoType expectedtype)
  • static void setInstancePrefix (const SbString &c)
  • static void setTraceRefs (SbBool trace)
  • static SbBool getTraceRefs (void)
  • static SbBool connectRoute (SoInput *input, const SbName &fromnodename, const SbName &fromfieldname, const SbName &tonodename, const SbName &tofieldname)
  • static SbBool readRoute (SoInput *input)

✨ Public Attributes ✨

  • SoSFInt32 numControlPoints
  • SoMFFloat knotVector

✨ Protected Member Functions ✨

  • virtual const SoFieldData * getFieldData (void) const
  • virtual ~SoNurbsCurve ()
  • virtual void generatePrimitives (SoAction *action)
  • virtual void computeBBox (SoAction *action, SbBox3f &box, SbVec3f &center)
  • virtual SoDetail * createLineSegmentDetail (SoRayPickAction *action, const SoPrimitiveVertex *v1, const SoPrimitiveVertex *v2, SoPickedPoint *pp)

✨ Protected Member Functions inherited from SoShape ✨

  • SoShape (void)
  • virtual ~SoShape ()
  • float getComplexityValue (SoAction *action)
  • virtual SbBool shouldGLRender (SoGLRenderAction *action)
  • void beginSolidShape (SoGLRenderAction *action)
  • void endSolidShape (SoGLRenderAction *action)
  • void GLRenderBoundingBox (SoGLRenderAction *action)
  • SbBool shouldPrimitiveCount (SoGetPrimitiveCountAction *action)
  • SbBool shouldRayPick (SoRayPickAction *const action)
  • void computeObjectSpaceRay (SoRayPickAction *const action)
  • void computeObjectSpaceRay (SoRayPickAction *const action, const SbMatrix &matrix)
  • virtual SoDetail * createTriangleDetail (SoRayPickAction *action, const SoPrimitiveVertex *v1, const SoPrimitiveVertex *v2, const SoPrimitiveVertex *v3, SoPickedPoint *pp)
  • virtual SoDetail * createPointDetail (SoRayPickAction *action, const SoPrimitiveVertex *v, SoPickedPoint *pp)
  • void invokeTriangleCallbacks (SoAction *const action, const SoPrimitiveVertex *const v1, const SoPrimitiveVertex *const v2, const SoPrimitiveVertex *const v3)
  • void invokeLineSegmentCallbacks (SoAction *const action, const SoPrimitiveVertex *const v1, const SoPrimitiveVertex *const v2)
  • void invokePointCallbacks (SoAction *const action, const SoPrimitiveVertex *const v)
  • void beginShape (SoAction *const action, const TriangleShape shapetype, SoDetail *const detail=NULL)
  • void shapeVertex (const SoPrimitiveVertex *const v)
  • void endShape (void)
  • void generateVertex (SoPrimitiveVertex *const pv, const SbVec3f &point, const SbBool useTexFunc, const SoMultiTextureCoordinateElement *const tce, const float s, const float t, 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 float r, const SbVec3f &normal)
  • SbBool startVertexArray (SoGLRenderAction *action, const SoCoordinateElement *coords, const SbVec3f *pervertexnormals, const SbBool texpervertex, const SbBool colorpervertex)
  • void finishVertexArray (SoGLRenderAction *action, const SbBool vbo, const SbBool normpervertex, 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 💖

bestie these are all the protected member funcs SoNurbsCurve picks up from SoBase:

  • SoBase (void)
  • virtual ~SoBase ()
  • virtual void destroy (void)
  • SbBool hasMultipleWriteRefs (void) const
  • SbBool writeHeader (SoOutput *out, SbBool isgroup, SbBool isengine) const
  • void writeFooter (SoOutput *out) const
  • virtual const char * getFileFormatName (void) const
  • virtual SoNotRec createNotRec (void)

🌸 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 void setNextActionMethodIndex (int index)
  • static int getNextActionMethodIndex (void)
  • static void incNextActionMethodIndex (void)
  • static void setCompatibilityTypes (const SoType &nodetype, const uint32_t bitmask)

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 SbUniqueId nextUniqueId = 1
  • static int nextActionMethodIndex = 0

🌈 Detailed Description 🌈

The SoNurbsCurve class is a node for representing smooth curves. slay, 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: WithHistorical 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".

🚨 okay so listen up bestie, this part MATTERS: 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 }

FILE FORMAT/DEFAULTS:

NurbsCurve {
    numControlPoints 0
    knotVector 0
}

🎀 Constructor & Destructor Documentation 🎀

SoNurbsCurve::SoNurbsCurve (void )

Constructor. the birth of a curve, iconic 🦋

SoNurbsCurve::~SoNurbsCurve () [protected], [virtual]

Destructor. rip curve 😭

✨ Member Function Documentation ✨

SoType SoNurbsCurve::getClassTypeId (void ) [static]

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

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.

const SoFieldData ** SoNurbsCurve::getFieldDataPtr (void ) [static], [protected]

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. so lowkey don't stress about it 💀

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

const SoFieldData * SoNurbsCurve::getFieldData (void ) const [protected], [virtual]

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

Reimplemented from SoShape.

void SoNurbsCurve::initClass (void ) [static]

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.

void SoNurbsCurve::rayPick (SoRayPickAction * action) [virtual]

Calculates picked point based on primitives generated by subclasses.

Reimplemented from SoShape.

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.

void SoNurbsCurve::getBoundingBox (SoGetBoundingBoxAction * action) [virtual]

Redefined to notify open caches that this shape contains lines.

Reimplemented from SoShape.

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. 💀 not implemented bestie, don't come for me

void SoNurbsCurve::generatePrimitives (SoAction * action) [protected], [virtual]

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.

void SoNurbsCurve::computeBBox (SoAction * action, SbBox3f & box, SbVec3f & center) [protected], [virtual]

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

Implements SoShape.

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

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.

🦋 Member Data Documentation 🦋

SoSFInt32 SoNurbsCurve::numControlPoints

Number of control points to use in this NURBS curve.

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.

🫶 Author 🫶

Generated automatically by Doxygen for Coin from the source code. no human wrote this one, it literally spawned itself ✨

and that's a wrap bestie 💅 this page is Version 4.0.10, dated Thu Jun 25 2026 00:00:00, and it's SoNurbsCurve(3) — go forth and tessellate responsibly, ily 🎀💖

📦 where this page comes from