NAME
SbViewVolume -
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.
SYNOPSIS
#include <Inventor/SbLinear.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=0) 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 SbVec3f & getProjectionPoint (void) const
const SbVec3f & getProjectionDirection (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
SbBool outsideTest (const SbPlane &p, const SbVec3f &bmin, const
SbVec3f &bmax) const
const SbDPViewVolume & getDPViewVolume (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().
Enumerator:
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 = 0) 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.
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);
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::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()
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 the
projection point, i.e. the camera position.
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.
SbBool SbViewVolume::intersect (const SbVec3f & p) const Returns TRUE if p
is inside the view volume.
Since:
Coin 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
SbBool SbViewVolume::intersect (const SbBox3f & box) const Returns TRUE if
box may be inside the view volume.
Since:
Coin 2.3
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.
const SbDPViewVolume & SbViewVolume::getDPViewVolume (void) const Returns
the double precision version of this view volume.
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.
Author
Generated automatically by Doxygen for Coin from the source code.