SbViewVolume(3)

📦 version 3.1.3, in fedora 43, fedora 44

💖 SbViewVolume(3) 💖

Library Functions Manual — SbViewVolume

okay bestie, sit down, hydrate, because we're about to get into the 3D math and honestly? it's giving iconic 💅

✨ NAME ✨

SbViewVolume — the SbViewVolume class is a viewing volume in 3D space.

🌈 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. Heads up bestie — this is the important part: the SbViewVolume instance will be uninitialized until you explicitly call ortho() or perspective(). no cap, don't be out here using it before that or it's giving chaos 😭

See also

  • ortho(), perspective().

🎀 SbViewVolume::~SbViewVolume (void )

Destructor. 🫶

🎀 Member Function Documentation 🎀

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

okay so bestie, this one is giving “give me both matrices at once.” It hands you the view volume’s affine matrix and projection matrix, and you pass in affine and proj as references so they can be filled. No return value, just vibes.

  • ✨ See also: getMatrix(), getCameraSpaceMatrix()

SbMatrix SbViewVolume::getMatrix (void ) const

Returns the combined affine and projection matrix. Like, one matrix that ate and left no crumbs. 💅

  • ✨ 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. It’s giving “reset the camera to home base.” 🏠

📝 Note: 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]. So like, keep it in the box, bestie. 📦

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. Two points, one line, iconic. ✨

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 — no clone needed, they can share. 🫶

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]. Periodt. 💅

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. It’s giving “plane parallel to the clipping planes, but make it opposite direction.” 🌈

  • ✨ 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. Basically the point straight ahead at distFromEye. 👀

  • ✨ 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

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. Default is FALSE, so if you don’t say anything, it’s not right-angle-only. 🎀

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. Math girlies rise. 🧮✨

SbVec2f SbViewVolume::projectBox (const SbBox3f & box) const

Projects the given box onto the projection plane and returns the normalized screen space it occupies. Box? Projected. Screen space? Normalized. Slay.

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. So z is like a depth dial. 🎚️

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. Perspective? She’s giving depth. 🔥

  • ✨ 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. Camera spin, no cap. 🌀

  • ✨ See also: translateCamera().

void SbViewVolume::translateCamera (const SbVec3f & v)

Translate the camera position of the view volume. Camera slide to the left, camera slide to the right. 🕺

  • ✨ 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(). Opposite vibes. 🔄

  • ✨ 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 \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().

void SbViewVolume::scale (float factor)

Scale width and height of viewing frustum by the given ratio around the projection plane center axis. It’s giving “zoom but for the frustum.” 🔍

  • ✨ 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. Width go brrr. 📏

  • ✨ 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. Height go brrr. 📐

  • ✨ See also: scale(), scaleWidth().

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

Return current view volume projection type, which can be either ORTHOGRAPHIC or PERSPECTIVE. Which one are you? 👀

  • ✨ See also: SbViewVolume::ProjectionType

const SbVec3f & SbViewVolume::getProjectionPoint (void ) const

Returns the projection point, i.e. the camera position. Where the camera at? Right here. 📍

const SbVec3f & SbViewVolume::getProjectionDirection (void ) const

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

  • ✨ See also: getNearDist().

float SbViewVolume::getNearDist (void ) const

Returns distance from projection plane to near clipping plane. Near distance, not far distance. Bestie, keep up. 😌

  • ✨ See also: getProjectionDirection().

float SbViewVolume::getWidth (void ) const

Returns width of viewing frustum in the projection plane. Width. That’s it. That’s the tweet. 🐦

  • ✨ See also: getHeight(), getDepth().

float SbViewVolume::getHeight (void ) const

Returns height of viewing frustum in the projection plane. Height. Vertical moment. ⬆️

  • ✨ 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. Depth, the final frontier. 🌌

  • ✨ 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. So if you’re optimized, this is a no-op, bestie. 💀

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. Matrix go brrr. 🔥

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. Up is up. ⬆️✨

SbBool SbViewVolume::intersect (const SbVec3f & p) const

Returns TRUE if p is inside the view volume. Inside? TRUE. Outside? Not today. 🚪

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. May be. No promises. 🙈

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. Eight corners, all outside? Then TRUE, bestie.

const SbDPViewVolume & SbViewVolume::getDPViewVolume (void ) const

Returns the double precision version of this view volume. Double the precision, double the fun. 💖

🫶 Member Data Documentation 🫶

Okay bestie, gather round. These are the data members of SbViewVolume, and every single one is tagged as internal to the library. That means the library considers them not likely to be of interest to the application programmer. Not me making it up — that's the official vibe. But because we're completionists, here's the whole roster, no skips. 💖

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 👑

Okay so this page? Generated automatically by Doxygen for Coin from the source code. So like, not a human author, just Doxygen doing its thing for Coin. 🤖✨

Vibe check on the footer: source is Coin, version is Version 3.1.3, and the page is SbViewVolume(3). There's no date in the footer, bestie — so we're not gonna invent one. Periodt. 💅✨

📦 where this page comes from