Main Page | Modules | Class Hierarchy | Alphabetical List | Class List | File List | Class Members

SbViewVolume Class Reference
[Base classes]

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

#include <Inventor/SbLinear.h>

List of all members.

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 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

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

enum SbViewVolume::ProjectionType
 

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

See also:
ortho(), perspective(), getProjectionType().
Enumeration values:
ORTHOGRAPHIC  Orthographic projection.
PERSPECTIVE  Perspective projection.


Constructor & Destructor Documentation

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 void   ) 
 

Destructor.


Member Function Documentation

void SbViewVolume::getMatrices SbMatrix affine,
SbMatrix proj
const
 

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

See also:
getMatrix(), getCameraSpaceMatrix()

SbMatrix SbViewVolume::getMatrix void   )  const
 

Returns the combined affine and projection matrix.

See also:
getMatrices(), 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()

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].

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.

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 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].

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()

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()

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].

SbRotation SbViewVolume::getAlignRotation SbBool  rightangleonly = FALSE  )  const
 

This method is obsoleted in Coin. Let us know if you need it, and we'll consider implementing it.

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.

SbVec2f SbViewVolume::projectBox const SbBox3f box  )  const
 

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

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.:

SbViewVolume view; 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()

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.

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().

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().

void SbViewVolume::rotateCamera const SbRotation q  ) 
 

Rotate the direction which the camera is pointing in.

See also:
translateCamera().

void SbViewVolume::translateCamera const SbVec3f v  ) 
 

Translate the camera position of the view volume.

See also:
rotateCamera().

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().

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 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().

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().

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().

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().

SbViewVolume::ProjectionType SbViewVolume::getProjectionType void   )  const
 

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

See also:
SbViewVolume::ProjectionType

const SbVec3f & SbViewVolume::getProjectionPoint void   )  const
 

Returns coordinates of center point in the projection plane.

const SbVec3f & SbViewVolume::getProjectionDirection void   )  const
 

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

See also:
getNearDist().

float SbViewVolume::getNearDist void   )  const
 

Returns distance from projection plane to near clipping plane.

See also:
getProjectionDirection().

float SbViewVolume::getWidth void   )  const
 

Returns width of viewing frustum in the projection plane.

See also:
getHeight(), getDepth().

float SbViewVolume::getHeight void   )  const
 

Returns height of viewing frustum in the projection plane.

See also:
getWidth(), 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().

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.

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.

void SbViewVolume::transform const SbMatrix matrix  ) 
 

Transform the viewing volume by matrix.

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.


Member Data Documentation

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.

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.

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.

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.

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.

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.

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.

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:
Generated on Tue Jul 27 23:53:09 2004 for Coin by doxygen 1.3.7