osg::LOD

osg::LOD Class Reference

Inheritance diagram for osg::LOD:


Public Types
typedef std::pair< float, float >	MinMaxPair
typedef std::vector< MinMaxPair >	RangeList
	USE_BOUNDING_SPHERE_CENTER
	USER_DEFINED_CENTER
	DISTANCE_FROM_EYE_POINT
	PIXEL_SIZE_ON_SCREEN
enum	CenterMode { USE_BOUNDING_SPHERE_CENTER, USER_DEFINED_CENTER }
enum	RangeMode { DISTANCE_FROM_EYE_POINT, PIXEL_SIZE_ON_SCREEN }
Public Member Functions
	LOD ()
	LOD (const LOD &, const CopyOp &copyop=CopyOp::SHALLOW_COPY)
	META_Node (osg, LOD)
virtual void	traverse (NodeVisitor &nv)
virtual bool	addChild (Node *child)
virtual bool	addChild (Node *child, float min, float max)
virtual bool	removeChildren (unsigned int pos, unsigned int numChildrenToRemove=1)
void	setCenterMode (CenterMode mode)
CenterMode	getCenterMode () const
void	setCenter (const Vec3 &center)
const Vec3 &	getCenter () const
void	setRadius (float radius)
float	getRadius () const
void	setRangeMode (RangeMode mode)
RangeMode	getRangeMode () const
void	setRange (unsigned int childNo, float min, float max)
float	getMinRange (unsigned int childNo) const
float	getMaxRange (unsigned int childNo) const
unsigned int	getNumRanges () const
void	setRangeList (const RangeList &rangeList)
const RangeList &	getRangeList () const
virtual BoundingSphere	computeBound () const
Protected Member Functions
virtual	~LOD ()
Protected Attributes
CenterMode	_centerMode
Vec3	_userDefinedCenter
float	_radius
RangeMode	_rangeMode
RangeList	_rangeList

Detailed Description

LOD - Level Of Detail group node which allows switching between children depending on distance from eye point. Typical uses are for load balancing - objects further away from the eye point are rendered at a lower level of detail, and at times of high stress on the graphics pipeline lower levels of detail can also be chosen. The children are ordered from most detailed (for close up views) to the least (see from a distance), and a set of ranges are used to decide which LOD is used at different view distances, the criteria used is child 'i' is used when range[i]<dist<range[i+1] is true. This requires there to be n+1 range values where the number of children is n, since no maximum distance of infinity is assumed. If the number of range values (m) is insufficient then the children m through to n will be ignored, only 0..m-1 will be used during rendering.

Member Typedef Documentation

typedef std::pair<float,float> osg::LOD::MinMaxPair

typedef std::vector<MinMaxPair> osg::LOD::RangeList

Member Enumeration Documentation

enum osg::LOD::CenterMode

Modes which control how the center of object should be determined when computing which child is active.

Enumerator:

USE_BOUNDING_SPHERE_CENTER
USER_DEFINED_CENTER

enum osg::LOD::RangeMode

Modes that control how the range values should be intepreted when computing which child is active.

Enumerator:

DISTANCE_FROM_EYE_POINT
PIXEL_SIZE_ON_SCREEN

Constructor & Destructor Documentation

osg::LOD::LOD ( )

osg::LOD::LOD	(	const LOD &	,
		const CopyOp &	copyop = `CopyOp::SHALLOW_COPY`
	)

Copy constructor using CopyOp to manage deep vs shallow copy.

virtual osg::LOD::~LOD ( ) [inline, protected, virtual]

Member Function Documentation

virtual bool osg::LOD::addChild	(	Node *	child,
		float	min,
		float	max
	)			`[virtual]`

Reimplemented in osg::PagedLOD.

virtual bool osg::LOD::addChild ( Node * child ) [virtual]

Add Node to Group. If node is not NULL and is not contained in Group then increment its reference count, add it to the child list and dirty the bounding sphere to force it to recompute on next getBound() and return true for success. Otherwise return false. Scene nodes can't be added as child nodes.

Reimplemented from osg::Group.

Reimplemented in osg::PagedLOD.

virtual BoundingSphere osg::LOD::computeBound ( ) const [virtual]

Compute the bounding sphere around Node's geometry or children. This method is automatically called by getBound() when the bounding sphere has been marked dirty via dirtyBound().

Reimplemented from osg::Group.

Reimplemented in osgSim::Impostor.

const Vec3& osg::LOD::getCenter ( ) const [inline]

return the LOD center point.

CenterMode osg::LOD::getCenterMode ( ) const [inline]

Get how the center of object should be determined when computing which child is active.

float osg::LOD::getMaxRange ( unsigned int childNo ) const [inline]

returns the max visible range for specified child.

float osg::LOD::getMinRange ( unsigned int childNo ) const [inline]

returns the min visible range for specified child.

unsigned int osg::LOD::getNumRanges ( ) const [inline]

returns the number of ranges currently set. An LOD which has been fully set up will have getNumChildren()==getNumRanges().

float osg::LOD::getRadius ( ) const [inline]

Get the object-space radius of the volume enclosed by the LOD.

const RangeList& osg::LOD::getRangeList ( ) const [inline]

return the list of MinMax ranges for each child.

RangeMode osg::LOD::getRangeMode ( ) const [inline]

Get how the range values should be intepreted when computing which child is active.

osg::LOD::META_Node	(	osg	,
		LOD
	)

virtual bool osg::LOD::removeChildren	(	unsigned int	pos,
		unsigned int	numChildrenToRemove = `1`
	)			`[virtual]`

Remove children from Group. Note, must be override by subclasses of Group which add per child attributes.

Reimplemented from osg::Group.

Reimplemented in osg::PagedLOD.

void osg::LOD::setCenter ( const Vec3 & center ) [inline]

Sets the object-space point which defines the center of the osg::LOD. center is affected by any transforms in the hierarchy above the osg::LOD.

void osg::LOD::setCenterMode ( CenterMode mode ) [inline]

Set how the center of object should be determined when computing which child is active.

void osg::LOD::setRadius ( float radius ) [inline]

Set the object-space reference radius of the volume enclosed by the LOD. Used to detmine the bounding sphere of the LOD in the absense of any children.