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The SbViewVolume class is a viewing volume in 3D space. More...
#include <Inventor/SbLinear.h>
Public Types | |
enum | ProjectionType { ORTHOGRAPHIC = 0 , PERSPECTIVE = 1 } |
Public Attributes | |
ProjectionType | type |
SbVec3f | projPoint |
SbVec3f | projDir |
float | nearDist |
float | nearToFar |
SbVec3f | llf |
SbVec3f | lrf |
SbVec3f | ulf |
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.
An SbViewVolume instance can represent either an orthogonal projection volume or a perspective projection volume.
Enumerator | |
---|---|
ORTHOGRAPHIC | Orthographic projection. |
PERSPECTIVE | Perspective projection. |
SbViewVolume::SbViewVolume | ( | void | ) |
Constructor. Note that the SbViewVolume instance will be uninitialized until you explicitly call ortho() or perspective().
SbViewVolume::~SbViewVolume | ( | void | ) |
Destructor.
Returns the view volume's affine matrix and projection matrix.
Referenced by SoCamera::doAction(), SoNurbsProfile::getVertices(), and SoCamera::GLRender().
Returns the combined affine and projection matrix.
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).
Project the given 2D point from the projection plane into a 3D line.
pt coordinates should be normalized to be within [0, 1].
References SbLine::setValue().
Referenced by SoRayPickAction::computeWorldSpaceRay(), and SbProjector::getWorkingLine().
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.
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].
Referenced by SbLineProjector::project().
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.
Referenced by SbLineProjector::project(), SbPlaneProjector::project(), and SbProjector::verifyProjection().
Returns the point on the center line-of-sight from the camera position with the given distance.
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.
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.
Referenced by SoTabPlaneDragger::reallyAdjustScaleTabSize().
Projects the given box onto the projection plane and returns the normalized screen space it occupies.
Referenced by SbProjector::findVanishingDistance().
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.:
..will give a view volume with corner points <25, 75> and <50, 100>.
Referenced by SoRayPickAction::computeWorldSpaceRay().
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]
Referenced by SoNurbsProfile::getVertices().
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.
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.
Referenced by SoFrustumCamera::getViewVolume(), and SoCamera::GLRender().
void SbViewVolume::rotateCamera | ( | const SbRotation & | q | ) |
Rotate the direction which the camera is pointing in.
References SbRotation::getValue().
Referenced by SoFrustumCamera::getViewVolume().
Translate the camera position of the view volume.
Referenced by SoFrustumCamera::getViewVolume(), SoOrthographicCamera::getViewVolume(), and SoPerspectiveCamera::getViewVolume().
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().
References projDir.
Referenced by SbCylinderProjector::isPointInFront(), and SbSphereProjector::isPointInFront().
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.
void SbViewVolume::scale | ( | float | factor | ) |
Scale width and height of viewing frustum by the given ratio around the projection plane center axis.
void SbViewVolume::scaleWidth | ( | float | ratio | ) |
Scale width of viewing frustum by the given ratio around the vertical center axis in the projection plane.
void SbViewVolume::scaleHeight | ( | float | ratio | ) |
Scale height of viewing frustum by the given ratio around the horizontal center axis in the projection plane.
SbViewVolume::ProjectionType SbViewVolume::getProjectionType | ( | void | ) | const |
Return current view volume projection type, which can be either ORTHOGRAPHIC or PERSPECTIVE.
References type.
Referenced by SoRayPickAction::computeWorldSpaceRay(), SbProjector::findVanishingDistance(), SbCylinderProjector::isPointInFront(), SbSphereProjector::isPointInFront(), print(), SbPlaneProjector::project(), and SbProjector::verifyProjection().
Returns the projection point, i.e. the camera position.
References projPoint.
Referenced by SoVRMLProximitySensor::doAction(), intersect(), SbCylinderProjector::isPointInFront(), SbSphereProjector::isPointInFront(), print(), SoLOD::whichToTraverse(), and SoVRMLLOD::whichToTraverse().
Returns the direction of projection, i.e. the direction the camera is pointing.
References projDir.
Referenced by SoRayPickAction::computeWorldSpaceRay(), SbProjector::findVanishingDistance(), SoCamera::GLRender(), intersect(), print(), SbCylinderSheetProjector::setupPlane(), SbPlaneProjector::setupPlane(), SbSphereSheetProjector::setupPlane(), SbCylinderSectionProjector::setupTolerance(), and SbSphereSectionProjector::setupTolerance().
float SbViewVolume::getNearDist | ( | void | ) | const |
Returns distance from projection plane to near clipping plane.
References nearDist.
Referenced by SoRayPickAction::computeWorldSpaceRay(), SoCamera::GLRender(), print(), SbLineProjector::project(), and SbPlaneProjector::project().
float SbViewVolume::getWidth | ( | void | ) | const |
Returns width of viewing frustum in the projection plane.
Referenced by SoCamera::audioRender(), SoRayPickAction::computeWorldSpaceRay(), SoCamera::doAction(), SoCamera::GLRender(), print(), and SoCamera::rayPick().
float SbViewVolume::getHeight | ( | void | ) | const |
Returns height of viewing frustum in the projection plane.
Referenced by SoCamera::audioRender(), SoRayPickAction::computeWorldSpaceRay(), SoCamera::doAction(), SbProjector::findVanishingDistance(), SoCamera::GLRender(), print(), and SoCamera::rayPick().
float SbViewVolume::getDepth | ( | void | ) | const |
Returns depth of viewing frustum, i.e. the distance from the near clipping plane to the far clipping plane.
References nearToFar.
Referenced by SoCamera::audioRender(), SoRayPickAction::computeWorldSpaceRay(), SoCamera::doAction(), SoCamera::GLRender(), print(), SbLineProjector::project(), SbPlaneProjector::project(), and SoCamera::rayPick().
Dump the state of this object to the file stream. Only works in debug version of library, method does nothing in an optimized compile.
References getDepth(), getHeight(), getNearDist(), getProjectionDirection(), getProjectionPoint(), getProjectionType(), getWidth(), llf, lrf, SbVec3f::print(), and ulf.
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.
Referenced by intersect(), and intersect().
Transform the viewing volume by matrix.
Referenced by SoCamera::audioRender(), SoCamera::doAction(), and SoCamera::GLRender().
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.
Referenced by SoCamera::GLRender(), SbCylinderSheetProjector::setupPlane(), and SbCylinderSectionProjector::setupTolerance().
Returns TRUE if p is inside the view volume.
References getViewVolumePlanes().
Referenced by intersect().
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.
References SbBox3f::extendBy(), SbLine::getClosestPoints(), getProjectionDirection(), getProjectionPoint(), and intersect().
SbBool SbViewVolume::outsideTest | ( | const SbPlane & | p, |
const SbVec3f & | bmin, | ||
const SbVec3f & | bmax | ||
) | const |
Returns TRUE if all eight corner points in bmin, bmax are outside p.
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.
Referenced by getProjectionType().
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.
Referenced by getProjectionPoint().
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.
Referenced by getProjectionDirection(), and zVector().
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.
Referenced by getNearDist().
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.
Referenced by getDepth().
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.
Referenced by print().
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.
Referenced by print().
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.
Referenced by print().
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