SoLevelOfDetail(3) Coin SoLevelOfDetail(3) NAME SoLevelOfDetail - The SoLevelOfDetail class is used to choose a child based on projected size. SYNOPSIS #include Inherits SoGroup. Public Member Functions virtual SoType getTypeId (void) const SoLevelOfDetail (void) SoLevelOfDetail (int numchildren) virtual void doAction (SoAction *action) virtual void callback (SoCallbackAction *action) virtual void GLRender (SoGLRenderAction *action) virtual void rayPick (SoRayPickAction *action) virtual void getBoundingBox (SoGetBoundingBoxAction *action) virtual void audioRender (SoAudioRenderAction *action) virtual void notify (SoNotList *nl) Public Member Functions inherited from SoGroup SoGroup (void) SoGroup (int nchildren) virtual void addChild (SoNode *node) virtual void insertChild (SoNode *child, int newchildindex) virtual SoNode * getChild (int index) const virtual int findChild (const SoNode *node) const virtual int getNumChildren (void) const virtual void removeChild (int childindex) virtual void removeChild (SoNode *child) virtual void removeAllChildren (void) virtual void replaceChild (int index, SoNode *newchild) virtual void replaceChild (SoNode *oldchild, SoNode *newchild) 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 getPrimitiveCount (SoGetPrimitiveCountAction *action) virtual SoChildList * getChildren (void) const virtual void addWriteReference (SoOutput *out, SbBool isfromfield=FALSE) 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 SoNode * copy (SbBool copyconnections=FALSE) const virtual SbBool affectsState (void) const virtual void GLRenderBelowPath (SoGLRenderAction *action) virtual void GLRenderInPath (SoGLRenderAction *action) virtual void GLRenderOffPath (SoGLRenderAction *action) virtual void grabEventsSetup (void) virtual void grabEventsCleanup (void) virtual void startNotify (void) SbUniqueId getNodeId (void) const virtual void writeInstance (SoOutput *out) virtual SoNode * addToCopyDict (void) const virtual SoFieldContainer * copyThroughConnection (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 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) 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. 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) 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 SoGroup 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 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 SoMFFloat screenArea Protected Member Functions virtual const SoFieldData * getFieldData (void) const virtual ~SoLevelOfDetail () Protected Member Functions inherited from SoGroup virtual ~SoGroup () virtual SbBool readInstance (SoInput *in, unsigned short flags) virtual SbBool readChildren (SoInput *in) virtual void copyContents (const SoFieldContainer *from, SbBool copyconnections) virtual SoNotRec createNotRec (void) void setOperation (const SoNotRec::OperationType opType=SoNotRec::UNSPECIFIED, const SoNode *cc=NULL, const SoNode *pc=NULL, const int ci=-1) Protected Member Functions inherited from SoNode SoNode (void) virtual ~SoNode () 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 Static Protected Member Functions static const SoFieldData ** getFieldDataPtr (void) Static Protected Member Functions inherited from SoGroup 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 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 SoGroup SoChildList * children 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 SoLevelOfDetail class is used to choose a child based on projected size. A level-of-detail mechanism is typically used by application programmers to assist the library in speeding up the rendering. The way a level-of-detail mechanism works is basically like this: Several versions of varying complexity of the same geometry / shape is provided by the application programmer in sorted order from "most complex" to "least complex" (where "complex" in this context should be taken to mean more or less detailed in the number of polygons / shapes used for rendering it). The runtime rendering system then, upon scene graph traversal, will on- the-fly calculate either the distance from the camera to the 3D-model in question, or the number of pixels in the screen projection of the 3D-model. This value is then used to decide which version of the model to actually render: as the model is moved farther away from the camera, a less detailed version of the model is used. And vice versa, as the model moves closer to the camera, more and more detailed versions of it are rendered. This is under many different circumstances a very effective way to let the application programmer assist to profoundly optimize the rendering of her 3D-scene. There is of course a trade-off with the level-of-detail technique: more versions of the same 3D model means the scene graph will use up more application memory resources. Also, generating the set of less and less detailed versions of a 3D model from the original is often not a trivial task to do properly. The process is often assisted by software like what Kongsberg Oil & Gas Technologies offers in their