Graphic3d_CullingTool Class Reference

Graphic3d_CullingTool class provides a possibility to store parameters of view volume, such as its vertices and equations, and contains methods detecting if given AABB overlaps view volume. More...

#include <Graphic3d_CullingTool.hxx>

Data Structures
struct	CullingContext
	Auxiliary structure holding non-persistent culling options. More...
struct	Plane
	Auxiliary structure representing 3D plane. More...

Public Member Functions
	Graphic3d_CullingTool ()
	Creates an empty selector object with parallel projection type by default.
void	SetViewVolume (const occ::handle< Graphic3d_Camera > &theCamera, const NCollection_Mat4< double > &theModelWorld=NCollection_Mat4< double >())
	Retrieves view volume's planes equations and its vertices from projection and world-view matrices.
void	SetViewportSize (int theViewportWidth, int theViewportHeight, double theResolutionRatio)
void	SetCullingDistance (CullingContext &theCtx, double theDistance) const
	Setup distance culling.
void	SetCullingSize (CullingContext &theCtx, double theSize) const
	Setup size culling.
void	CacheClipPtsProjections ()
	Caches view volume's vertices projections along its normals and AABBs dimensions. Must be called at the beginning of each BVH tree traverse loop.
bool	IsCulled (const CullingContext &theCtx, const NCollection_Vec3< double > &theMinPnt, const NCollection_Vec3< double > &theMaxPnt, bool *theIsInside=nullptr) const
	Checks whether given AABB should be entirely culled or not.
const occ::handle< Graphic3d_Camera > &	Camera () const
	Return the camera definition.
const NCollection_Mat4< double > &	ProjectionMatrix () const
	Returns current projection matrix.
const NCollection_Mat4< double > &	WorldViewMatrix () const
	Returns current world view transformation matrix.
int	ViewportWidth () const
int	ViewportHeight () const
const Graphic3d_WorldViewProjState &	WorldViewProjState () const
	Returns state of current world view projection transformation matrices.
const NCollection_Vec3< double > &	CameraEye () const
	Returns camera eye position.
const NCollection_Vec3< double > &	CameraDirection () const
	Returns camera direction.
double	SignedPlanePointDistance (const NCollection_Vec4< double > &theNormal, const NCollection_Vec4< double > &thePnt)
	Calculates signed distance from plane to point.
bool	IsOutFrustum (const NCollection_Vec3< double > &theMinPnt, const NCollection_Vec3< double > &theMaxPnt, bool *theIsInside=nullptr) const
	Detects if AABB overlaps view volume using separating axis theorem (SAT).
bool	IsTooDistant (const CullingContext &theCtx, const NCollection_Vec3< double > &theMinPnt, const NCollection_Vec3< double > &theMaxPnt, bool *theIsInside=nullptr) const
	Returns TRUE if given AABB should be discarded by distance culling criterion.
bool	IsTooSmall (const CullingContext &theCtx, const NCollection_Vec3< double > &theMinPnt, const NCollection_Vec3< double > &theMaxPnt) const
	Returns TRUE if given AABB should be discarded by size culling criterion.

Protected Types
enum	{   Plane_Left , Plane_Right , Plane_Bottom , Plane_Top ,   Plane_Near , Plane_Far , PlanesNB }
	Enumerates planes of view volume. More...

Protected Attributes
Plane	myClipPlanes [PlanesNB]
	Planes.
NCollection_Array1< NCollection_Vec3< double > >	myClipVerts
	Vertices.
occ::handle< Graphic3d_Camera >	myCamera
	camera definition
double	myMaxClipProjectionPts [PlanesNB]
	Max view volume's vertices projections onto its normals.
double	myMinClipProjectionPts [PlanesNB]
	Min view volume's vertices projections onto its normals.
double	myMaxOrthoProjectionPts [3]
	Max view volume's vertices projections onto normalized dimensions of AABB.
double	myMinOrthoProjectionPts [3]
	Min view volume's vertices projections onto normalized dimensions of AABB.
bool	myIsProjectionParallel
NCollection_Mat4< double >	myProjectionMat
NCollection_Mat4< double >	myWorldViewMat
int	myViewportWidth
int	myViewportHeight
Graphic3d_WorldViewProjState	myWorldViewProjState
	State of world view projection matrices.
NCollection_Vec3< double >	myCamEye
	camera eye position for distance culling
NCollection_Vec3< double >	myCamDir
	camera direction for size culling
double	myCamScale
	camera scale for size culling
double	myPixelSize
	pixel size for size culling

Detailed Description

Graphic3d_CullingTool class provides a possibility to store parameters of view volume, such as its vertices and equations, and contains methods detecting if given AABB overlaps view volume.

Member Enumeration Documentation

anonymous enum

anonymous enum

protected

Enumerates planes of view volume.

Enumerator
Plane_Left
Plane_Right
Plane_Bottom
Plane_Top
Plane_Near
Plane_Far
PlanesNB

Constructor & Destructor Documentation

Graphic3d_CullingTool()

Graphic3d_CullingTool::Graphic3d_CullingTool

(

)

Creates an empty selector object with parallel projection type by default.

Member Function Documentation

CacheClipPtsProjections()

void Graphic3d_CullingTool::CacheClipPtsProjections

(

)

Caches view volume's vertices projections along its normals and AABBs dimensions. Must be called at the beginning of each BVH tree traverse loop.

Camera()

const occ::handle< Graphic3d_Camera > & Graphic3d_CullingTool::Camera ( ) const

inline

Return the camera definition.

CameraDirection()

const NCollection_Vec3< double > & Graphic3d_CullingTool::CameraDirection ( ) const

inline

Returns camera direction.

CameraEye()

const NCollection_Vec3< double > & Graphic3d_CullingTool::CameraEye ( ) const

inline

Returns camera eye position.

IsCulled()

bool Graphic3d_CullingTool::IsCulled ( const CullingContext & theCtx, const NCollection_Vec3< double > & theMinPnt, const NCollection_Vec3< double > & theMaxPnt, bool * theIsInside = nullptr ) const

inline

Checks whether given AABB should be entirely culled or not.

Parameters

[in]	theCtx	culling properties
[in]	theMinPnt	maximum point of AABB
[in]	theMaxPnt	minimum point of AABB
[out]	theIsInside	flag indicating if AABB is fully inside; initial value should be set to TRUE

Returns

TRUE if AABB is completely outside of view frustum or culled by size/distance; FALSE in case of partial or complete overlap (use theIsInside to distinguish)

IsOutFrustum()

bool Graphic3d_CullingTool::IsOutFrustum ( const NCollection_Vec3< double > & theMinPnt, const NCollection_Vec3< double > & theMaxPnt, bool * theIsInside = nullptr ) const

inline

Detects if AABB overlaps view volume using separating axis theorem (SAT).

Parameters

[in]	theMinPnt	maximum point of AABB
[in]	theMaxPnt	minimum point of AABB
[out]	theIsInside	flag indicating if AABB is fully inside; initial value should be set to TRUE

Returns

TRUE if AABB is completely outside of view frustum; FALSE in case of partial or complete overlap (use theIsInside to distinguish)

See also

SelectMgr_Frustum::hasOverlap()

IsTooDistant()

bool Graphic3d_CullingTool::IsTooDistant ( const CullingContext & theCtx, const NCollection_Vec3< double > & theMinPnt, const NCollection_Vec3< double > & theMaxPnt, bool * theIsInside = nullptr ) const

inline

Returns TRUE if given AABB should be discarded by distance culling criterion.

Parameters

[in]	theMinPnt	maximum point of AABB
[in]	theMaxPnt	minimum point of AABB
[out]	theIsInside	flag indicating if AABB is fully inside; initial value should be set to TRUE

Returns

TRUE if AABB is completely behind culling distance; FALSE in case of partial or complete overlap (use theIsInside to distinguish)

IsTooSmall()

bool Graphic3d_CullingTool::IsTooSmall ( const CullingContext & theCtx, const NCollection_Vec3< double > & theMinPnt, const NCollection_Vec3< double > & theMaxPnt ) const

inline

Returns TRUE if given AABB should be discarded by size culling criterion.

ProjectionMatrix()

const NCollection_Mat4< double > & Graphic3d_CullingTool::ProjectionMatrix ( ) const

inline

Returns current projection matrix.

SetCullingDistance()

void Graphic3d_CullingTool::SetCullingDistance	(	CullingContext &	theCtx,
		double	theDistance ) const

Setup distance culling.

SetCullingSize()

void Graphic3d_CullingTool::SetCullingSize	(	CullingContext &	theCtx,
		double	theSize ) const

Setup size culling.

SetViewportSize()

void Graphic3d_CullingTool::SetViewportSize	(	int	theViewportWidth,
		int	theViewportHeight,
		double	theResolutionRatio )

SetViewVolume()

void Graphic3d_CullingTool::SetViewVolume	(	const occ::handle< Graphic3d_Camera > &	theCamera,
		const NCollection_Mat4< double > &	theModelWorld = NCollection_Mat4< double >() )

Retrieves view volume's planes equations and its vertices from projection and world-view matrices.

Parameters

[in]	theCamera	camera definition
[in]	theModelWorld	optional object transformation for computing frustum in object local coordinate system

SignedPlanePointDistance()

double Graphic3d_CullingTool::SignedPlanePointDistance	(	const NCollection_Vec4< double > &	theNormal,
		const NCollection_Vec4< double > &	thePnt )

Calculates signed distance from plane to point.

Parameters

[in]	theNormal	the plane's normal.
[in]	thePnt

ViewportHeight()

int Graphic3d_CullingTool::ViewportHeight ( ) const

inline

ViewportWidth()

int Graphic3d_CullingTool::ViewportWidth ( ) const

inline

WorldViewMatrix()

const NCollection_Mat4< double > & Graphic3d_CullingTool::WorldViewMatrix ( ) const

inline

Returns current world view transformation matrix.

WorldViewProjState()

const Graphic3d_WorldViewProjState & Graphic3d_CullingTool::WorldViewProjState ( ) const

inline

Returns state of current world view projection transformation matrices.

Field Documentation

myCamDir

NCollection_Vec3<double> Graphic3d_CullingTool::myCamDir

protected

camera direction for size culling

myCamera

occ::handle<Graphic3d_Camera> Graphic3d_CullingTool::myCamera

protected

camera definition

myCamEye

NCollection_Vec3<double> Graphic3d_CullingTool::myCamEye

protected

camera eye position for distance culling

myCamScale

double Graphic3d_CullingTool::myCamScale

protected

camera scale for size culling

myClipPlanes

Plane Graphic3d_CullingTool::myClipPlanes[PlanesNB]

protected

Planes.

myClipVerts

NCollection_Array1<NCollection_Vec3<double> > Graphic3d_CullingTool::myClipVerts

protected

Vertices.

myIsProjectionParallel

bool Graphic3d_CullingTool::myIsProjectionParallel

protected

myMaxClipProjectionPts

double Graphic3d_CullingTool::myMaxClipProjectionPts[PlanesNB]

protected

Max view volume's vertices projections onto its normals.

myMaxOrthoProjectionPts

double Graphic3d_CullingTool::myMaxOrthoProjectionPts[3]

protected

Max view volume's vertices projections onto normalized dimensions of AABB.

myMinClipProjectionPts

double Graphic3d_CullingTool::myMinClipProjectionPts[PlanesNB]

protected

Min view volume's vertices projections onto its normals.

myMinOrthoProjectionPts

double Graphic3d_CullingTool::myMinOrthoProjectionPts[3]

protected

Min view volume's vertices projections onto normalized dimensions of AABB.

myPixelSize

double Graphic3d_CullingTool::myPixelSize

protected

pixel size for size culling

myProjectionMat

NCollection_Mat4<double> Graphic3d_CullingTool::myProjectionMat

protected

myViewportHeight

int Graphic3d_CullingTool::myViewportHeight

protected

myViewportWidth

int Graphic3d_CullingTool::myViewportWidth

protected

myWorldViewMat

NCollection_Mat4<double> Graphic3d_CullingTool::myWorldViewMat

protected

myWorldViewProjState

Graphic3d_WorldViewProjState Graphic3d_CullingTool::myWorldViewProjState

protected

State of world view projection matrices.

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

• Graphic3d_CullingTool.hxx