SoLevelOfDetail(3IV)
SoLevelOfDetail - level-of-detail switching group node
Showing IRIX 6.5.30 (default release). Added in IRIX 6.5.22.
NAME SoLevelOfDetail - level-of-detail switching group node INHERITS FROM SoBase > SoFieldContainer > SoNode > SoGroup > SoLevelOfDetail SYNOPSIS #include <Inventor/nodes/SoLevelOfDetail.h> Fields from class SoLevelOfDetail: SoMFFloat screenArea Methods from class SoLevelOfDetail: SoLevelOfDetail() static SoType getClassTypeId() Methods from class SoGroup: void addChild(SoNode *child) void insertChild(SoNode *child, int newChildIndex) SoNode * getChild(int index) const int findChild(const SoNode *child) const int getNumChildren() const void removeChild(int index) void removeChild(SoNode *child) void removeAllChildren() void replaceChild(int index, SoNode *newChild) void replaceChild(SoNode *oldChild, SoNode *newChild) Methods from class SoNode: void setOverride(SbBool state) SbBool isOverride() const SoNode * copy(SbBool copyConnections = FALSE) const virtual SbBool affectsState() const static SoNode * getByName(const SbName &name) static int getByName(const SbName &name, SoNodeList &list) Methods from class SoFieldContainer: void setToDefaults() SbBool hasDefaultValues() const SbBool fieldsAreEqual(const SoFieldContainer *fc) const void copyFieldValues(const SoFieldContainer *fc, SbBool copyConnections = FALSE) SbBool set(const char *fieldDataString) void get(SbString &fieldDataString) virtual int getFields(SoFieldList &resultList) const virtual SoField * getField(const SbName &fieldName) const SbBool getFieldName(const SoField *field, SbName &fieldName) const SbBool isNotifyEnabled() const SbBool enableNotify(SbBool flag) Methods from class SoBase: void ref() void unref() const void unrefNoDelete() const void touch() virtual SoType getTypeId() const SbBool isOfType(SoType type) const virtual void setName(const SbName &name) virtual SbName getName() const DESCRIPTION The children of this node typically represent the same object or objects at varying levels of detail, from highest detail to lowest. The size of the objects when projected into the viewport is used to determine which version to use (i.e., which child to traverse). The size is computed as the area of the screen rectangle enclosing the projection of the 3D bounding box that encloses all of the children. When rendering, this size is compared to the values in the screenArea field. If the size is greater than the first value, child 0 is traversed. If it is smaller than the first, but greater than the second, child 1 is traversed, and so on. If there are fewer children than are required by this rule, the last child is traversed. The screenArea field contains just 0 by default, so the first child is always traversed. The size calculation takes the current complexity into account. If the complexity is 0 or is of type BOUNDING_BOX, the last child is always traversed. If the complexity is less than .5, the computed size is scaled down appropriately to use (possibly) a less detailed representation. If the complexity is greater than .5, the size is scaled up. At complexity 1, the first child is always used. Note that the SoLOD node is similar to SoLevelOfDetail, except the switching between levels in the SoLOD node is based on distance from the camera, which is faster than using screen area. FIELDS SoMFFloat screenArea Areas to use for comparison METHODS SoLevelOfDetail() Creates a level-of-detail node with default settings. static SoType getClassTypeId() Returns type identifier for this class. ACTION BEHAVIOR SoGLRenderAction, SoRayPickAction, SoCallbackAction Only the child with the appropriate level of detail is traversed. SoGetBoundingBoxAction The box that encloses all children is computed. (This is the box that is needed to compute the projected size.) others All implemented as for SoGroup. FILE FORMAT/DEFAULTS LevelOfDetail { screenArea 0 } SEE ALSO SoLOD, SoComplexity, SoSwitch, SoGroup