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SoLevelOfDetail(3IV)() SoLevelOfDetail(3IV)()

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