SoShapeHints Class Reference

Node that provides hints about shapes. More...

#include <Inventor/nodes/SoShapeHints.h>

Inheritance diagram for SoShapeHints:

Public Types
enum	VertexOrdering { UNKNOWN_ORDERING = SoShapeHintsElement::UNKNOWN_ORDERING , CLOCKWISE = SoShapeHintsElement::CLOCKWISE , COUNTERCLOCKWISE = SoShapeHintsElement::COUNTERCLOCKWISE }
	Hints about ordering of face vertices: if ordering of all vertices of all faces is known to be consistent when viewed from "outside" shape or not. More...
enum	ShapeType { UNKNOWN_SHAPE_TYPE = SoShapeHintsElement::UNKNOWN_SHAPE_TYPE , SOLID = SoShapeHintsElement::SOLID }
	Hints about entire shape: if shape is known to be a solid object, as opposed to a surface. More...
enum	FaceType { UNKNOWN_FACE_TYPE = SoShapeHintsElement::UNKNOWN_FACE_TYPE , CONVEX = SoShapeHintsElement::CONVEX }
	Hints about faces of shape: if all faces are known to be convex or not. More...
Public Types inherited from SoNode
enum	Stage { FIRST_INSTANCE , PROTO_INSTANCE , OTHER_INSTANCE }

Fields
SoSFEnum	vertexOrdering
	Indicates how the vertices of faces are ordered.
SoSFEnum	shapeType
	Indicates whether the shape is known to enclose a volume (SOLID) or not.
SoSFEnum	faceType
	Indicates whether each face is convex.
SoSFFloat	creaseAngle
	Indicates the minimum angle (in radians) between two adjacent face normals required to form a sharp crease at the edge when default normals are computed and used.
SoSFBool	useVBO
	Allows shapes to make use of vertex buffer objects if available.
	SoShapeHints ()
	Creates a shape hints node with default settings.
virtual void	doAction (SoAction *action)
	This method performs the "typical" operation of a node for any action.
virtual void	GLRender (SoGLRenderAction *action)
	These virtual functions implement all of the actions for nodes, Most of the default implementations do nothing.
virtual void	callback (SoCallbackAction *action)
virtual void	pick (SoPickAction *action)
virtual void	getBoundingBox (SoGetBoundingBoxAction *action)
static void	initClass ()
virtual	~SoShapeHints ()

Additional Inherited Members
Public Member Functions inherited from SoNode
void	setOverride (bool state)
	Turns override flag on or off.
bool	isOverride () const
	Returns the state of the override flag.
SoNode *	copy (bool copyConnections=FALSE) const
	Creates and returns an exact copy of the node.
virtual bool	affectsState () const
	Returns TRUE if a node has an effect on the state during traversal.
virtual void	doAction (SoAction *action)
	This method performs the "typical" operation of a node for any action.
virtual void	GLRender (SoGLRenderAction *action)
	These virtual functions implement all of the actions for nodes, Most of the default implementations do nothing.
virtual void	callback (SoCallbackAction *action)
virtual void	getBoundingBox (SoGetBoundingBoxAction *action)
virtual void	getMatrix (SoGetMatrixAction *action)
virtual void	handleEvent (SoHandleEventAction *action)
virtual void	pick (SoPickAction *action)
virtual void	rayPick (SoRayPickAction *action)
virtual void	search (SoSearchAction *action)
virtual void	write (SoWriteAction *action)
virtual void	GLRenderBelowPath (SoGLRenderAction *action)
	These methods make render traversal faster by implementing different rendering paths corresponding to different action path codes.
virtual void	GLRenderInPath (SoGLRenderAction *action)
virtual void	GLRenderOffPath (SoGLRenderAction *action)
virtual void	grabEventsSetup ()
	These virtual functions are called when a node gains or loses status as "grabber" of events (see HandleEventAction::setGrabber()).
virtual void	grabEventsCleanup ()
virtual void	startNotify ()
	Initiates notification from an instance.
virtual void	notify (SoNotList *list)
	Propagates modification notification through an instance.
SbNodeIdType	getNodeId () const
	Returns the unique id for a node.
virtual SoChildList *	getChildren () const
	Returns pointer to children, or NULL if none.
virtual void	writeInstance (SoOutput *out)
	Writes instance to SoOutput. (Used for either stage of writing.)
virtual SoNode *	addToCopyDict () const
	Recursively adds this node and all nodes under it to the copy dictionary.
virtual void	copyContents (const SoFieldContainer *fromFC, bool copyConnections)
	Copies the contents of the given node into this instance.
virtual SoFieldContainer *	copyThroughConnection () const
	Copies an instance that is encountered through a field connection.
Public Member Functions inherited from SoFieldContainer
void	setToDefaults ()
	Sets all fields in this object to their default values.
bool	hasDefaultValues () const
	Returns TRUE if all of the object's fields have their default values.
bool	fieldsAreEqual (const SoFieldContainer *fc) const
	Returns TRUE if this object's fields are exactly equal to fc's fields.
void	copyFieldValues (const SoFieldContainer *fc, bool copyConnections=FALSE)
	Copies the contents of fc's fields into this object's fields.
bool	set (const char *fieldDataString)
	Sets one or more fields in this object to the values specified in the given string, which should be a string in the Inventor file format.
void	get (SbString &fieldDataString)
	Returns the values of the fields of this object in the Inventor ASCII file format in the given string.
virtual int	getFields (SoFieldList &list) const
	Appends pointers to all of this object's fields to resultList, and returns the number of fields appended.
virtual SoField *	getField (const SbName &fieldName) const
	Returns a pointer to the field with the given name.
bool	getFieldName (const SoField *field, SbName &fieldName) const
	Returns the name of the given field in the fieldName argument.
bool	enableNotify (bool flag)
	Notification at this Field Container is enabled (if flag == TRUE) or disabled (if flag == FALSE).
bool	isNotifyEnabled () const
	Notification is the process of telling interested objects that this object has changed.
bool	set (const char *fieldDataString, SoInput *dictIn)
	Sets one or more fields in this object to the values specified in the given string, which should be a string in the Inventor file format.
void	get (SbString &fieldDataString, SoOutput *dictOut)
	Returns the values of the fields of this object in the Inventor ASCII file format in the given string.
virtual void	notify (SoNotList *)
	Propagates modification notification through an instance.
virtual void	addWriteReference (SoOutput *out, bool isFromField=FALSE)
	Adds a reference to the instance when writing.
virtual void	writeInstance (SoOutput *out)
	Writes instance to SoOutput. (Used only for last stage of writing)
bool	getIsBuiltIn () const
	Returns whether or not instance is considered 'built-in' to the library.
virtual const SoFieldData *	getFieldData () const
	Returns an SoFieldData structure for the node.
virtual void	copyContents (const SoFieldContainer *fromFC, bool copyConnections)
	Copies the contents of the given node into this instance.
virtual SoFieldContainer *	copyThroughConnection () const
	During a copy operation, this copies an instance that is encountered through a field connection.
void	addManagedSensor (SoSensor *sensor)
	Adds a sensor which is managed by the field container.
Public Member Functions inherited from SoBase
void	ref () const
	Adds and removes a reference to an instance.
void	unref () const
void	unrefNoDelete () const
void	touch ()
	Marks an instance as modified, simulating a change to it.
virtual SoType	getTypeId () const =0
	Returns the type identifier for a specific instance.
bool	isOfType (SoType type) const
	Returns TRUE if this object is of the type specified in type or is derived from that type.
virtual SbName	getName () const
	Returns the name of an instance.
virtual void	setName (const SbName &name)
	Sets the name of an instance.
virtual void	startNotify ()
	Initiates notification from an instance.
virtual void	notify (SoNotList *list)
	Propagates modification notification through an instance.
void	addAuditor (void *auditor, SoNotRec::Type type)
	Adds/removes an auditor to/from list.
void	removeAuditor (void *auditor, SoNotRec::Type type)
const SoAuditorList &	getAuditors ()
	Returns auditor list– used by SoField and SoEngineOutput to trace forward connections.
int	getRefCount () const
	Returns current reference count.
virtual void	addWriteReference (SoOutput *out, bool isFromField=FALSE)
	Adds a reference to the instance when writing.
bool	shouldWrite ()
	Returns TRUE if the instance should be written, based on the write-reference info already accumulated.
Static Public Member Functions inherited from SoNode
static SoType	getClassTypeId ()
	Returns type identifier for the SoNode class.
static SoNode *	getByName (const SbName &name)
	Returns the last node given the specified name.
static int	getByName (const SbName &name, SoNodeList &list)
	Returns the number of nodes with the given name, and adds to list pointers to those nodes.
static void	initClass ()
	Initializes base node class.
static void	initClasses ()
	Initialize ALL Inventor node classes.
static SbNodeIdType	getNextNodeId ()
	Returns the next available unique id.
static int	getActionMethodIndex (SoType t)
	Returns the index of this node in the action/method table, given its type.
Static Public Member Functions inherited from SoFieldContainer
static SoType	getClassTypeId ()
	Returns the type of this class.
static void	initClass ()
	Setup type information.
static void	initCopyDict ()
	During a copy operation, copies of nodes and engines are stored in a dictionary, keyed by the original node or engine pointer, so that copies can be re-used.
static void	addCopy (const SoFieldContainer *orig, const SoFieldContainer *copy)
	Adds an instance to the dictionary.
static SoFieldContainer *	checkCopy (const SoFieldContainer *orig)
	If a copy of the given instance is in the dictionary, this returns it.
static SoFieldContainer *	findCopy (const SoFieldContainer *orig, bool copyConnections)
	If a copy of the given instance is not in the dictionary, this returns NULL.
static void	copyDone ()
	Cleans up the dictionary when done.
Static Public Member Functions inherited from SoBase
static SoType	getClassTypeId ()
	Returns type identifier for this class.
static void	initClass ()
	Setup type information.
static void	incrementCurrentWriteCounter ()
	Increments the current write counter at the start of a write operation.
static void	decrementCurrentWriteCounter ()
	Decrements the current write counter after a write operation, in some rare cases.
static void	addName (SoBase *, const char *)
	Internal methods used to maintain the global name dictionary.
static void	removeName (SoBase *, const char *)
static SoBase *	getNamedBase (const SbName &, SoType)
	Helper routines used to get stuff out of nameDict.
static int	getNamedBases (const SbName &, SoBaseList &, SoType)
static bool	read (SoInput *in, SoBase *&base, SoType expectedType)
	Reads one instance of some subclass of SoBase.
static void	setInstancePrefix (const SbString &c)
	This defaults to "+" and is used when naming nodes that are DEF's and USE'd.
Static Public Attributes inherited from SoBase
static bool	traceRefs
	Turns on/off reference count tracing (for debugging)
Protected Types inherited from SoBase
enum	BaseFlags { IS_ENGINE = 1 , IS_GROUP = 2 }
	This set of enums is used when reading and writing the base. More...
Protected Member Functions inherited from SoNode
	SoNode ()
	Constructor, destructor.
virtual	~SoNode ()
Protected Member Functions inherited from SoFieldContainer
	SoFieldContainer ()
	~SoFieldContainer ()
virtual bool	readInstance (SoInput *in, unsigned short flags)
	Reads stuff into instance. Returns FALSE on error.
Protected Member Functions inherited from SoBase
	SoBase ()
	Constructor is protected - this is an abstract class.
virtual	~SoBase ()
	Virtual destructor so that subclasses are deleted properly.
virtual void	destroy ()
	Actually deletes an instance.
bool	hasMultipleWriteRefs () const
	Returns TRUE if the instance has multiple write references.
bool	writeHeader (SoOutput *out, bool isGroup, bool isEngine) const
	Writes a header (name, open brace) or footer (close brace) to file defined by SoOutput.
void	writeFooter (SoOutput *out) const
virtual const char *	getFileFormatName () const
	Unknown nodes and engines write a different name for themselves than their typeId; this virtual method lets them do that (by default the typeId name is returned)
virtual bool	readInstance (SoInput *in, unsigned short flags)=0
	Reads stuff into instance of subclass.
Static Protected Member Functions inherited from SoNode
static const SoFieldData **	getFieldDataPtr ()
	This is used by the field-inheritence mechanism, hidden in the SoSubNode macros.
Static Protected Member Functions inherited from SoBase
static uint32_t	getCurrentWriteCounter ()
	Returns current write counter.
Protected Attributes inherited from SoNode
SbNodeIdType	uniqueId
	Unique id for this node.
Protected Attributes inherited from SoFieldContainer
bool	isBuiltIn
	Is the subclass a built-in Inventor subclass or an extender subclass? This is used to determine whether to read/write field type information.
Static Protected Attributes inherited from SoNode
static SbNodeIdType	nextUniqueId
	Next available unique id.
static int	nextActionMethodIndex
	Next index into the action method table.

Detailed Description

By default, Inventor assumes very little about the shapes it renders. You can use the SoShapeHints node to indicate that vertex-based shapes (those derived from SoVertexShape) are solid, contain ordered vertices, or contain convex faces. For fastest rendering, specify SOLID, COUNTERCLOCKWISE, CONVEX shapes.

These hints allow Inventor to optimize certain rendering features. Optimizations that may be performed include enabling back-face culling and disabling two-sided lighting. For example, if an object is solid and has ordered vertices, Inventor turns on backface culling and turns off two-sided lighting. If the object is not solid but has ordered vertices, it turns off backface culling and turns on two-sided lighting. In all other cases, both backface culling and two-sided lighting are off.

The SoShapeHints node also affects how default normals are generated. When a node derived from SoVertexShape has to generate default normals, it uses the creaseAngle field to determine which edges should be smooth-shaded and which ones should have a sharp crease. The crease angle is the angle between surface normals on adjacent polygons. For example, a crease angle of .5 radians means that an edge between two adjacent polygonal faces will be smooth shaded if the normals to the two faces form an angle that is less than .5 radians (about 30 degrees). Otherwise, it will be faceted. Normal generation is fastest when the creaseAngle is 0 (the default), producing one normal per facet. A creaseAngle of pi produces one averaged normal per vertex.

File Format/Default

ShapeHints {
  vertexOrdering UNKNOWN_ORDERING
  shapeType UNKNOWN_SHAPE_TYPE
  faceType CONVEX
  creaseAngle 0
  useVBO TRUE
}

Action Behavior

SoGLRenderAction, SoCallbackAction, SoRayPickAction, SoGetBoundingBoxAction
Sets the state to contain the hints; sets up optimizations based on the hints.

See Also

SoVertexShape

Definition at line 123 of file SoShapeHints.h.

Member Enumeration Documentation

FaceType

enum SoShapeHints::FaceType

Enumerator
UNKNOWN_FACE_TYPE
CONVEX

Definition at line 146 of file SoShapeHints.h.

ShapeType

enum SoShapeHints::ShapeType

Enumerator
UNKNOWN_SHAPE_TYPE
SOLID

Definition at line 139 of file SoShapeHints.h.

VertexOrdering

enum SoShapeHints::VertexOrdering

Enumerator
UNKNOWN_ORDERING
CLOCKWISE
COUNTERCLOCKWISE

Definition at line 131 of file SoShapeHints.h.

Constructor & Destructor Documentation

SoShapeHints()

SoShapeHints::SoShapeHints

(

)

~SoShapeHints()

virtual SoShapeHints::~SoShapeHints ( )

protectedvirtual

Member Function Documentation

callback()

virtual void SoShapeHints::callback ( SoCallbackAction *  action )

virtual

Reimplemented from SoNode.

doAction()

virtual void SoShapeHints::doAction ( SoAction *  action )

virtual

The default implementation does nothing.

Reimplemented from SoNode.

getBoundingBox()

virtual void SoShapeHints::getBoundingBox ( SoGetBoundingBoxAction *  action )

virtual

Reimplemented from SoNode.

GLRender()

virtual void SoShapeHints::GLRender ( SoGLRenderAction *  action )

virtual

Reimplemented from SoNode.

initClass()

static void SoShapeHints::initClass ( )

static

pick()

virtual void SoShapeHints::pick ( SoPickAction *  action )

virtual

Reimplemented from SoNode.

Member Data Documentation

creaseAngle

SoSFFloat SoShapeHints::creaseAngle

Definition at line 175 of file SoShapeHints.h.

faceType

SoSFEnum SoShapeHints::faceType

Because the penalty for non-convex faces is very steep (faces must be triangulated expensively), the default assumes all faces are convex. Therefore, shapes with concave faces may not be displayed correctly unless this hint is set to UNKNOWN_FACE_TYPE.

Definition at line 170 of file SoShapeHints.h.

shapeType

SoSFEnum SoShapeHints::shapeType

If the inside (the side away from the surface normal) of any part of the shape is visible, the shape is not solid.

Definition at line 163 of file SoShapeHints.h.

useVBO

SoSFBool SoShapeHints::useVBO

Definition at line 177 of file SoShapeHints.h.

vertexOrdering

SoSFEnum SoShapeHints::vertexOrdering

CLOCKWISE ordering means that the vertices of each face form a clockwise loop around the face, when viewed from the outside (the side toward which the normal points).

Definition at line 158 of file SoShapeHints.h.

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

• C:/jh/mevislab/4.0.2_1/build/MeVis/ThirdParty/Sources/Inventor/include/Inventor/nodes/SoShapeHints.h