Provided by: libcoin60-doc_3.1.3-2_all bug

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=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 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 floatdistFromEye) 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 floatdistFromEye) 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 floatdistFromEye, 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 (SbBoolrightangleonly = 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.

   float SbViewVolume::getWorldToScreenScale (const SbVec3f &worldCenter, floatnormRadius) 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 (floatleft, floatbottom, floatright, floattop) 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 (floatleft, floatright, floatbottom, floattop, floatnearval,
       floatfarval) 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 (floatfovy, floataspect, floatnearval, floatfarval) 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 (floatleft, floatright, floatbottom, floattop, floatnearval,
       floatfarval) 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 (floatnearval, floatfarval) 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 (floatfactor) Scale width and height of viewing frustum by the given
       ratio around the projection plane center axis.
       See also:
           scaleWidth(), scaleHeight().

   void SbViewVolume::scaleWidth (floatratio) 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 (floatratio) 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 (SbPlaneplanes[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

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