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SoNurbsCurve Class Reference

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

#include <Inventor/nodes/SoNurbsCurve.h>

Inheritance diagram for SoNurbsCurve:
SoShape SoNode SoFieldContainer SoBase

Public Member Functions

virtual SoType getTypeId (void) const
 Returns the type identification of an object derived from a class inheriting SoBase. This is used for runtime type checking and "downward" casting. More...
 
 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
virtual SbBool affectsState (void) const
 
virtual void notify (SoNotList *nl)
 
virtual void callback (SoCallbackAction *action)
 
const SoBoundingBoxCachegetBoundingBoxCache (void) const
 
- Public Member Functions inherited from SoNode
void setOverride (const SbBool state)
 
SbBool isOverride (void) const
 
void setNodeType (const NodeType type)
 
NodeType getNodeType (void) const
 
virtual SoNodecopy (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 SoChildListgetChildren (void) const
 
virtual void writeInstance (SoOutput *out)
 
virtual SoNodeaddToCopyDict (void) const
 
virtual void copyContents (const SoFieldContainer *from, SbBool copyconnections)
 
virtual SoFieldContainercopyThroughConnection (void) const
 
- Public Member Functions inherited from SoFieldContainer
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 SoFieldgetField (const SbName &name) const
 
virtual SoFieldgetEventIn (const SbName &name) const
 
virtual SoFieldgetEventOut (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
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. More...
 
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 SoAuditorListgetAuditors (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)
 
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 SoNodegetByName (const SbName &name)
 
static int getByName (const SbName &name, SoNodeList &l)
 
static void initClass (void)
 
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)
 
static SoType getClassTypeId (void)
 
static void cleanupClass (void)
 
static void initCopyDict (void)
 
static void addCopy (const SoFieldContainer *orig, const SoFieldContainer *copy)
 
static SoFieldContainercheckCopy (const SoFieldContainer *orig)
 
static SoFieldContainerfindCopy (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 SoBasegetNamedBase (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 SoFieldDatagetFieldData (void) const
 
virtual ~SoNurbsCurve ()
 
virtual void generatePrimitives (SoAction *action)
 
virtual void computeBBox (SoAction *action, SbBox3f &box, SbVec3f &center)
 
virtual SoDetailcreateLineSegmentDetail (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 SoDetailcreateTriangleDetail (SoRayPickAction *action, const SoPrimitiveVertex *v1, const SoPrimitiveVertex *v2, const SoPrimitiveVertex *v3, SoPickedPoint *pp)
 
virtual SoDetailcreatePointDetail (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
 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.

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 {
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 }
nurbscurve-circle.png
Rendering of Example Scenegraph

FILE FORMAT/DEFAULTS:

NurbsCurve {
}

Constructor & Destructor Documentation

◆ SoNurbsCurve()

SoNurbsCurve::SoNurbsCurve ( void  )

Constructor.

◆ ~SoNurbsCurve()

SoNurbsCurve::~SoNurbsCurve ( )
protectedvirtual

Destructor.

Member Function Documentation

◆ 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.

Usage example:

void foo(SoNode * node)
{
if (node->getTypeId() == SoFile::getClassTypeId()) {
SoFile * filenode = (SoFile *)node; // safe downward cast, knows the type
}
}

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in all subclasses. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the predefined macros available through for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.

For more information on writing Coin extensions, see the class documentation of the top level superclasses for the various class groups.

Reimplemented from SoShape.

◆ 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.

◆ 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.

◆ rayPick()

void SoNurbsCurve::rayPick ( SoRayPickAction action)
virtual

Calculates picked point based on primitives generated by subclasses.

Reimplemented from SoShape.

◆ 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.

◆ getBoundingBox()

void SoNurbsCurve::getBoundingBox ( SoGetBoundingBoxAction action)
virtual

Redefined to notify open caches that this shape contains lines.

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.

◆ 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.

◆ 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.

Member Data Documentation

◆ numControlPoints

SoSFInt32 SoNurbsCurve::numControlPoints

Number of control points to use in this NURBS curve.

◆ 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.


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