3D viewing volume class. More...

#include <Inventor/SbLinear.h>

Public Types
enum	ProjectionType { ORTHOGRAPHIC, PERSPECTIVE }
	Return projection information. More...
Public Member Functions
	SbViewVolume ()
	Constructor and destructor.
	~SbViewVolume ()
	Constructor and destructor.
void	getMatrices (SbMatrix &affine, SbMatrix &proj) const
	Returns two matrices corresponding to the view volume.
SbMatrix	getMatrix () const
	Like the method above, but returns the affine and projection parts together in one matrix (i.e., affine.multRight( proj ) ).
SbMatrix	getCameraSpaceMatrix () const
	Returns a matrix that transforms the view volume into camera space: it translates the view volume so the viewpoint is at the origin, and rotates it so the view direction is along the negative z axis.
void	projectPointToLine (const SbVec2f &pt, SbLine &line) const
	Maps a 2d point (in 0 <= x,y <= 1) to a 3d line.
void	projectPointToLine (const SbVec2f &pt, SbVec3f &line0, SbVec3f &line1) const
void	projectToScreen (const SbVec3f &src, SbVec3f &dst) const
	Maps the 3D point in world coordinates to a 2D point in normalized screen coordinates (0 <= x,y,z <= 1).
SbPlane	getPlane (float distFromEye) const
	Returns a plane parallel to the near (or far) plane of the view volume at a given distance from the projection point (eye).
SbVec3f	getSightPoint (float distFromEye) const
	Returns the point along the line of sight at the given distance from the projection point (eye).
SbVec3f	getPlanePoint (float distFromEye, const SbVec2f &normPoint) const
	Returns the projection of a given point in normalized screen coordinates (see projectToScreen()) onto the plane parallel to the near plane that is at `distFromEye` units from the eye.
SbRotation	getAlignRotation (SbBool rightAngleOnly=FALSE) const
	Returns a rotation that would align a viewed object so that its positive x-axis (of its object space) is to the right in the view and its positive y-axis is up.
float	getWorldToScreenScale (const SbVec3f &worldCenter, float normRadius) const
	Returns a scale factor that would scale a unit sphere centered at `worldCenter` so that it would appear to have the given radius in normalized screen coordinates when projected onto the near plane.
SbVec2f	projectBox (const SbBox3f &box) const
	Projects the given 3D bounding box onto the near plane and returns the size (in normalized screen coordinates) of the rectangular region that encloses it.
SbViewVolume	narrow (float left, float bottom, float right, float top) const
	Given a view volume, this narrows the view to the given sub-rectangle of the near plane.
SbViewVolume	narrow (const SbBox3f &box) const
	Narrow a view volume by the given box.
void	ortho (float left, float right, float bottom, float top, float nearVal, float farVal)
	Sets up an orthographic view volume with the given sides.
void	perspective (float fovy, float aspect, float nearVal, float farVal)
	Sets up a perspective view volume with the given field of view and aspect ratio.
void	rotateCamera (const SbRotation &q)
	Rotate the camera view direction.
void	translateCamera (const SbVec3f &v)
	Translate the camera viewpoint.
SbVec3f	zVector () const
	Returns the positive z axis in eye space.
SbViewVolume	zNarrow (float nearVal, float farVal) const
	Returns a narrowed view volume which contains as tightly as possible the given interval on the z axis (in eye space).
void	scale (float factor)
	Scales width and height of view volume by given factor.
void	scaleWidth (float ratio)
	Scales view volume to be the given ratio of its current width, leaving the resulting view volume centered about the same point (in the near plane) as the current one.
void	scaleHeight (float ratio)
	Scales view volume to be the given ratio of its current height, leaving the resulting view volume centered about the same point (in the near plane) as the current one.
ProjectionType	getProjectionType () const
	Returns projection information.
const SbVec3f &	getProjectionPoint () const
	Returns projection information.
const SbVec3f &	getProjectionDirection () const
	Returns projection information.
float	getNearDist () const
	Returns distance from projection point to near plane.
float	getWidth () const
	Returns bounds of viewing frustum.
float	getHeight () const
	Returns bounds of viewing frustum.
float	getDepth () const
	Returns bounds of viewing frustum.
void	transform (const SbMatrix &matrix)
	Transforms the view volume by the given matrix.
SbBool	intersect (const SbVec3f &point) const
	Returns TRUE if view volume contains point.
SbBool	intersect (const SbVec3f &p0, const SbVec3f &p1, SbVec3f &closestPoint) const
	Returns TRUE if line segment between 2 points may intersect volume.
SbBool	intersect (const SbBox3f &box) const
	Returns TRUE if bounding box may intersect volume.
SbBool	outsideTest (const SbPlane &p, const SbVec3f &min, const SbVec3f &max) const
	Returns TRUE if the bounding box defined by min,max is totally outside plane p.
Public Attributes
ProjectionType	type
SbVec3f	projPoint
	Note that there is redundant info in this data structure and its elements should not be changed by hand.
SbVec3f	projDir
float	nearDist
	distance to near plane
float	nearToFar
	distance between z clips
SbVec3f	llf
SbVec3f	lrf
SbVec3f	ulf

Detailed Description

Class used to represent a 3D viewing volume. This class is used to represent viewing frusta and picking volumes. For perspective projection, the view volume is a frustum. For orthographic (parallel) projection, the view volume is a rectangular prism.

See Also

: SbVec3f, SbVec2f, SbBox3f, SbMatrix, SbRotation

Definition at line 961 of file SbLinear.h.

Member Enumeration Documentation

enum SbViewVolume::ProjectionType

Enumerator:

ORTHOGRAPHIC
PERSPECTIVE

Definition at line 1091 of file SbLinear.h.

Constructor & Destructor Documentation

SbViewVolume::SbViewVolume ( )

SbViewVolume::~SbViewVolume ( ) [inline]

Definition at line 967 of file SbLinear.h.

Member Function Documentation

SbRotation SbViewVolume::getAlignRotation ( SbBool rightAngleOnly = FALSE ) const

If rightAngleOnly is TRUE, it will come as close as it can to this goal by using only 90 degree rotations.

SbMatrix SbViewVolume::getCameraSpaceMatrix ( ) const

float SbViewVolume::getDepth ( ) const [inline]

Definition at line 1113 of file SbLinear.h.

float SbViewVolume::getHeight ( ) const [inline]

Definition at line 1111 of file SbLinear.h.

void SbViewVolume::getMatrices	(	SbMatrix &	affine,
		SbMatrix &	proj
	)		const

The first is a viewing matrix, which is guaranteed to be an affine transformation. The second is suitable for use as a projection matrix in OpenGL.

SbMatrix SbViewVolume::getMatrix ( ) const

float SbViewVolume::getNearDist ( ) const [inline]

Definition at line 1106 of file SbLinear.h.

SbPlane SbViewVolume::getPlane ( float distFromEye ) const

SbVec3f SbViewVolume::getPlanePoint	(	float	distFromEye,
		const SbVec2f &	normPoint
	)		const

const SbVec3f& SbViewVolume::getProjectionDirection ( ) const [inline]

Definition at line 1103 of file SbLinear.h.

const SbVec3f& SbViewVolume::getProjectionPoint ( ) const [inline]

Definition at line 1100 of file SbLinear.h.

ProjectionType SbViewVolume::getProjectionType ( ) const [inline]

Definition at line 1097 of file SbLinear.h.

SbVec3f SbViewVolume::getSightPoint ( float distFromEye ) const

float SbViewVolume::getWidth ( ) const [inline]

Definition at line 1109 of file SbLinear.h.

float SbViewVolume::getWorldToScreenScale	(	const SbVec3f &	worldCenter,
		float	normRadius
	)		const

SbBool SbViewVolume::intersect ( const SbVec3f & point ) const

SbBool SbViewVolume::intersect	(	const SbVec3f &	p0,
		const SbVec3f &	p1,
		SbVec3f &	closestPoint
	)		const

Returns closest point on line to center ray of volume if intersection is found.

SbBool SbViewVolume::intersect ( const SbBox3f & box ) const

SbViewVolume SbViewVolume::narrow	(	float	left,
		float	bottom,
		float	right,
		float	top
	)		const

The coordinates of the rectangle are between 0 and 1, where (0,0) is the lower-left corner of the near plane and (1,1) is the upper-right corner.

SbViewVolume SbViewVolume::narrow ( const SbBox3f & box ) const

The box must lie inside the unit cube, and the view will be shrunk according to the size of the box.

void SbViewVolume::ortho	(	float	left,
		float	right,
		float	bottom,
		float	top,
		float	nearVal,
		float	farVal
	)

The parameters are the same as for the OpenGL glOrtho() routine.

SbBool SbViewVolume::outsideTest	(	const SbPlane &	p,
		const SbVec3f &	min,
		const SbVec3f &	max
	)		const

void SbViewVolume::perspective	(	float	fovy,
		float	aspect,
		float	nearVal,
		float	farVal
	)

The parameters are the same as for the OpenGL gluPerspective() routine, except that the field of view angle is specified in radians.

SbVec2f SbViewVolume::projectBox ( const SbBox3f & box ) const

void SbViewVolume::projectPointToLine	(	const SbVec2f &	pt,
		SbVec3f &	line0,
		SbVec3f &	line1
	)		const

void SbViewVolume::projectPointToLine	(	const SbVec2f &	pt,
		SbLine &	line
	)		const

void SbViewVolume::projectToScreen	(	const SbVec3f &	src,
		SbVec3f &	dst
	)		const

The z-screen coordinate represents the homogenized z coordinate which goes (nonlinearly) from 0 at the near clipping plane to 1 at the far clipping plane.

void SbViewVolume::rotateCamera ( const SbRotation & q )

Note that this accomplishes the reverse of doing an OpenGL glRotate() command after defining a camera, which rotates the scene viewed by the camera.

void SbViewVolume::scale ( float factor )

void SbViewVolume::scaleHeight ( float ratio )

void SbViewVolume::scaleWidth ( float ratio )

void SbViewVolume::transform ( const SbMatrix & matrix )

NOTE: if the matrix performs a scale and a rotation, angles between the transformed projection direction and the sides of the view volume may not be preserved.

void SbViewVolume::translateCamera ( const SbVec3f & v )

Note that this accomplishes the reverse of doing an OpenGL glTranslate() command after defining a camera, which translates the scene viewed by the camera.

SbViewVolume SbViewVolume::zNarrow	(	float	nearVal,
		float	farVal
	)		const

The returned view volume will never be larger than the current volume, however. near and far are given in terms of zVector(): this means that near > far must hold.

SbVec3f SbViewVolume::zVector ( ) const

In this coordinate system, the z value of the near plane should be GREATER than the z value of the far plane.