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SbViewVolume Class Reference

The SbViewVolume class is a viewing volume in 3D space. More...

#include <Inventor/SbViewVolume.h>

Public Types

enum  ProjectionType { ORTHOGRAPHIC = 0, PERSPECTIVE = 1 }
 

Public Member Functions

 SbViewVolume (void)
 
 ~SbViewVolume (void)
 
void getMatrices (SbMatrix &affine, SbMatrix &proj) const
 
SbMatrix getMatrix (void) const
 
SbMatrix getCameraSpaceMatrix (void) const
 
void projectPointToLine (const SbVec2f &pt, SbLine &line) const
 
void projectPointToLine (const SbVec2f &pt, SbVec3f &line0, SbVec3f &line1) const
 
void projectToScreen (const SbVec3f &src, SbVec3f &dst) const
 
SbPlane getPlane (const float distFromEye) const
 
SbVec3f getSightPoint (const float distFromEye) const
 
SbVec3f getPlanePoint (const float distFromEye, const SbVec2f &normPoint) const
 
SbRotation getAlignRotation (SbBool rightAngleOnly=FALSE) const
 
float getWorldToScreenScale (const SbVec3f &worldCenter, float normRadius) const
 
SbVec2f projectBox (const SbBox3f &box) const
 
SbViewVolume narrow (float left, float bottom, float right, float top) const
 
SbViewVolume narrow (const SbBox3f &box) const
 
void ortho (float left, float right, float bottom, float top, float nearval, float farval)
 
void perspective (float fovy, float aspect, float nearval, float farval)
 
void frustum (float left, float right, float bottom, float top, float nearval, float farval)
 
void rotateCamera (const SbRotation &q)
 
void translateCamera (const SbVec3f &v)
 
SbVec3f zVector (void) const
 
SbViewVolume zNarrow (float nearval, float farval) const
 
void scale (float factor)
 
void scaleWidth (float ratio)
 
void scaleHeight (float ratio)
 
ProjectionType getProjectionType (void) const
 
const SbVec3fgetProjectionPoint (void) const
 
const SbVec3fgetProjectionDirection (void) const
 
float getNearDist (void) const
 
float getWidth (void) const
 
float getHeight (void) const
 
float getDepth (void) const
 
void print (FILE *fp) const
 
void getViewVolumePlanes (SbPlane planes[6]) const
 
void transform (const SbMatrix &matrix)
 
SbVec3f getViewUp (void) const
 
SbBool intersect (const SbVec3f &p) const
 
SbBool intersect (const SbVec3f &p0, const SbVec3f &p1, SbVec3f &closestpoint) const
 
SbBool intersect (const SbBox3f &box) const
 
SbBox3f intersectionBox (const SbBox3f &box) const
 
SbBool outsideTest (const SbPlane &p, const SbVec3f &bmin, const SbVec3f &bmax) const
 
const SbDPViewVolumegetDPViewVolume (void) const
 

Public Attributes

ProjectionType type
 
SbVec3f projPoint
 
SbVec3f projDir
 
float nearDist
 
float nearToFar
 
SbVec3f llf
 
SbVec3f lrf
 
SbVec3f ulf
 

Detailed Description

The SbViewVolume class is a viewing volume in 3D space.

This class contains the necessary information for storing a view volume. It has methods for projection of primitives into the 3D volume from 2D points in the projection plane or vice versa, doing camera transforms, view volume transforms, etc.

See also
SbViewportRegion

Member Enumeration Documentation

◆ ProjectionType

An SbViewVolume instance can represent either an orthogonal projection volume or a perspective projection volume.

See also
ortho(), perspective(), getProjectionType().
Enumerator
ORTHOGRAPHIC 

Orthographic projection.

PERSPECTIVE 

Perspective projection.

Constructor & Destructor Documentation

◆ SbViewVolume()

SbViewVolume::SbViewVolume ( void  )

Constructor. Note that the SbViewVolume instance will be uninitialized until you explicitly call ortho() or perspective().

See also
ortho(), perspective().

◆ ~SbViewVolume()

SbViewVolume::~SbViewVolume ( void  )

Destructor.

Member Function Documentation

◆ getMatrices()

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

Returns the view volume's affine matrix and projection matrix.

See also
getMatrix(), getCameraSpaceMatrix()

◆ getMatrix()

SbMatrix SbViewVolume::getMatrix ( void  ) const

Returns the combined affine and projection matrix.

See also
getMatrices(), getCameraSpaceMatrix()

◆ getCameraSpaceMatrix()

SbMatrix SbViewVolume::getCameraSpaceMatrix ( void  ) const

Returns a matrix which will translate the view volume camera back to origo, and rotate the camera so it'll point along the negative z axis.

Note that the matrix will not include the rotation necessary to make the camera up vector point along the positive y axis (i.e. camera roll is not accounted for).

See also
getMatrices(), getMatrix()

◆ projectPointToLine() [1/2]

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

Project the given 2D point from the projection plane into a 3D line.

pt coordinates should be normalized to be within [0, 1].

◆ projectPointToLine() [2/2]

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

Project the given 2D point from the projection plane into two points defining a 3D line. The first point, line0, will be the corresponding point for the projection on the near plane, while line1 will be the line endpoint, lying in the far plane.

◆ projectToScreen()

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

Project the src point to a normalized set of screen coordinates in the projection plane and place the result in dst.

It is safe to let src and dst be the same SbVec3f instance.

The z-coordinate of dst is monotonically increasing for points closer to the far plane. Note however that this is not a linear relationship, the dst z-coordinate is calculated as follows:

Orthogonal view: DSTz = (-2 * SRCz - far - near) / (far - near), Perspective view: DSTz = (-SRCz * (far - near) - 2*far*near) / (far - near)

The returned coordinates (dst) are normalized to be in range [0, 1].

◆ getPlane()

SbPlane SbViewVolume::getPlane ( const float  distFromEye) const

Returns an SbPlane instance which has a normal vector in the opposite direction of which the camera is pointing. This means the plane will be parallel to the near and far clipping planes.

See also
getSightPoint()

◆ getSightPoint()

SbVec3f SbViewVolume::getSightPoint ( const float  distFromEye) const

Returns the point on the center line-of-sight from the camera position with the given distance.

See also
getPlane()

◆ getPlanePoint()

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

Return the 3D point which projects to normPoint and lies on the plane perpendicular to the camera direction and distFromEye distance away from the camera position.

normPoint should be given in normalized coordinates, where the visible render canvas is covered by the range [0.0, 1.0].

◆ getAlignRotation()

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

Returns a rotation that aligns an object so that its positive x-axis is to the right and its positive y-axis is up in the view volume.

If rightangleonly is TRUE, it will create a rotation that aligns the x and y-axis with the closest orthogonal axes to right and up.

◆ getWorldToScreenScale()

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

Given a sphere with center in worldCenter and an initial radius of 1.0, return the scale factor needed to make this sphere have a normRadius radius when projected onto the near clipping plane.

◆ projectBox()

SbVec2f SbViewVolume::projectBox ( const SbBox3f box) const

Projects the given box onto the projection plane and returns the normalized screen space it occupies.

◆ narrow() [1/2]

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

Returns a narrowed version of the view volume which is within the given [0, 1] normalized coordinates. The coordinates are taken to be corner points of a normalized "view window" on the near clipping plane. I.e.:

view.ortho(0, 100, 0, 100, 0.1, 1000);
view = view.narrow(0.25, 0.5, 0.75, 1.0);

..will give a view volume with corner points <25, 75> and <50, 100>.

See also
scale(), scaleWidth(), scaleHeight()

◆ narrow() [2/2]

SbViewVolume SbViewVolume::narrow ( const SbBox3f box) const

Returns a narrowed version of the view volume which is within the given [0, 1] normalized coordinates. The box x and y coordinates are taken to be corner points of a normalized "view window" on the near clipping plane. The box z coordinates are used to adjust the near and far clipping planes, and should be relative to the current clipping planes. A value of 1.0 is at the current near plane. A value of 0.0 is at the current far plane.

◆ ortho()

void SbViewVolume::ortho ( float  left,
float  right,
float  bottom,
float  top,
float  nearval,
float  farval 
)

Set up the view volume as a rectangular box for orthographic parallel projections.

The line of sight will be along the negative z axis, through the center of the plane defined by the point

[(right+left)/2, (top+bottom)/2, 0]
See also
perspective().

◆ perspective()

void SbViewVolume::perspective ( float  fovy,
float  aspect,
float  nearval,
float  farval 
)

Set up the view volume for perspective projections. The line of sight will be through origo along the negative z axis.

See also
ortho().

◆ frustum()

void SbViewVolume::frustum ( float  left,
float  right,
float  bottom,
float  top,
float  nearval,
float  farval 
)

Set up the frustum for perspective projection. This is an alternative to perspective() that lets you specify any kind of view volumes (e.g. off center volumes). It has the same arguments and functionality as the corresponding OpenGL glFrustum() function.

This function is an extension for Coin, and it is not available in the original SGI Open Inventor v2.1 API.

Since
Coin 2.0
See also
perspective()

◆ rotateCamera()

void SbViewVolume::rotateCamera ( const SbRotation q)

Rotate the direction which the camera is pointing in.

See also
translateCamera().

◆ translateCamera()

void SbViewVolume::translateCamera ( const SbVec3f v)

Translate the camera position of the view volume.

See also
rotateCamera().

◆ zVector()

SbVec3f SbViewVolume::zVector ( void  ) const

Return the vector pointing from the center of the view volume towards the camera. This is just the vector pointing in the opposite direction of getProjectionDirection().

See also
getProjectionDirection().

◆ zNarrow()

SbViewVolume SbViewVolume::zNarrow ( float  nearval,
float  farval 
) const

Return a copy SbViewVolume with narrowed depth by supplying parameters for new near and far clipping planes.

nearval and farval should be relative to the current clipping planes. A value of 1.0 is at the current near plane. A value of 0.0 is at the current far plane.

See also
zVector().

◆ scale()

void SbViewVolume::scale ( float  factor)

Scale width and height of viewing frustum by the given ratio around the projection plane center axis.

See also
scaleWidth(), scaleHeight().

◆ scaleWidth()

void SbViewVolume::scaleWidth ( float  ratio)

Scale width of viewing frustum by the given ratio around the vertical center axis in the projection plane.

See also
scale(), scaleHeight().

◆ scaleHeight()

void SbViewVolume::scaleHeight ( float  ratio)

Scale height of viewing frustum by the given ratio around the horizontal center axis in the projection plane.

See also
scale(), scaleWidth().

◆ getProjectionType()

SbViewVolume::ProjectionType SbViewVolume::getProjectionType ( void  ) const

Return current view volume projection type, which can be either ORTHOGRAPHIC or PERSPECTIVE.

See also
SbViewVolume::ProjectionType

◆ getProjectionPoint()

const SbVec3f & SbViewVolume::getProjectionPoint ( void  ) const

Returns the projection point, i.e. the camera position.

◆ getProjectionDirection()

const SbVec3f & SbViewVolume::getProjectionDirection ( void  ) const

Returns the direction of projection, i.e. the direction the camera is pointing.

See also
getNearDist().

◆ getNearDist()

float SbViewVolume::getNearDist ( void  ) const

Returns distance from projection plane to near clipping plane.

See also
getProjectionDirection().

◆ getWidth()

float SbViewVolume::getWidth ( void  ) const

Returns width of viewing frustum in the projection plane.

See also
getHeight(), getDepth().

◆ getHeight()

float SbViewVolume::getHeight ( void  ) const

Returns height of viewing frustum in the projection plane.

See also
getWidth(), getDepth().

◆ getDepth()

float SbViewVolume::getDepth ( void  ) const

Returns depth of viewing frustum, i.e. the distance from the near clipping plane to the far clipping plane.

See also
getWidth(), getHeight().

◆ print()

void SbViewVolume::print ( FILE *  fp) const

Dump the state of this object to the file stream. Only works in debug version of library, method does nothing in an optimized compile.

◆ getViewVolumePlanes()

void SbViewVolume::getViewVolumePlanes ( SbPlane  planes[6]) const

Returns the six planes defining the view volume in the following order: left, bottom, right, top, near, far. Plane normals are directed into the view volume.

This method is an extension for Coin, and is not available in the original Open Inventor.

◆ transform()

void SbViewVolume::transform ( const SbMatrix matrix)

Transform the viewing volume by matrix.

◆ getViewUp()

SbVec3f SbViewVolume::getViewUp ( void  ) const

Returns the view up vector for this view volume. It's a vector which is perpendicular to the projection direction, and parallel and oriented in the same direction as the vector from the lower left corner to the upper left corner of the near plane.

◆ intersect() [1/3]

SbBool SbViewVolume::intersect ( const SbVec3f p) const

Returns TRUE if p is inside the view volume.

Since
Coin 2.3

◆ intersect() [2/3]

SbBool SbViewVolume::intersect ( const SbVec3f p0,
const SbVec3f p1,
SbVec3f closestpoint 
) const

Returns TRUE if the line segment p0, p1 may intersect volume. Be aware that it's not 100% certain that the line segment intersects the volume even if this function returns TRUE.

closestpoint is set to the closest point on the line to the center ray of the view volume.

Since
Coin 2.3

◆ intersect() [3/3]

SbBool SbViewVolume::intersect ( const SbBox3f box) const

Returns TRUE if box may be inside the view volume.

Since
Coin 2.3

◆ intersectionBox()

SbBox3f SbViewVolume::intersectionBox ( const SbBox3f box) const

Calculates the bbox of the intersection between bbox and the view volume.

Since
Coin 4.0

◆ outsideTest()

SbBool SbViewVolume::outsideTest ( const SbPlane p,
const SbVec3f bmin,
const SbVec3f bmax 
) const

Returns TRUE if all eight corner points in bmin, bmax is outside p.

◆ getDPViewVolume()

const SbDPViewVolume & SbViewVolume::getDPViewVolume ( void  ) const

Returns the double precision version of this view volume.

Member Data Documentation

◆ type

SbViewVolume::ProjectionType SbViewVolume::type

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ projPoint

SbVec3f SbViewVolume::projPoint

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ projDir

SbVec3f SbViewVolume::projDir

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ nearDist

float SbViewVolume::nearDist

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ nearToFar

float SbViewVolume::nearToFar

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ llf

SbVec3f SbViewVolume::llf

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ lrf

SbVec3f SbViewVolume::lrf

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ ulf

SbVec3f SbViewVolume::ulf

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.


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