qglviewer::Camera Class Reference

A perspective or orthographic camera. More...

`#include <QGLViewer/camera.h>`

## Public Types | |

enum | Type { PERSPECTIVE, ORTHOGRAPHIC } |

## Public Member Functions | |

Camera () | |

Camera (const Camera &camera) | |

Camera & | operator= (const Camera &camera) |

virtual | ~Camera () |

## Private Attributes | |

float | fieldOfView_ |

float | focusDistance_ |

ManipulatedCameraFrame * | frame_ |

KeyFrameInterpolator * | interpolationKfi_ |

float | IODistance_ |

QMap< int, KeyFrameInterpolator * > | kfi_ |

GLdouble | modelViewMatrix_ [16] |

float | orthoCoef_ |

float | physicalScreenWidth_ |

GLdouble | projectionMatrix_ [16] |

Vec | sceneCenter_ |

float | sceneRadius_ |

int | screenHeight_ |

int | screenWidth_ |

Type | type_ |

float | zClippingCoef_ |

float | zNearCoef_ |

## Friends | |

class | ::QGLViewer |

## Position and orientation | |

Vec | position () const |

Vec | upVector () const |

Vec | viewDirection () const |

Vec | rightVector () const |

Quaternion | orientation () const |

void | setFromModelViewMatrix (const GLdouble *const modelViewMatrix) |

void | setFromProjectionMatrix (const float matrix[12]) |

void | setPosition (const Vec &pos) |

void | setOrientation (const Quaternion &q) |

void | setOrientation (float theta, float phi) |

void | setUpVector (const Vec &up, bool noMove=true) |

void | setViewDirection (const Vec &direction) |

## Positioning tools | |

void | lookAt (const Vec &target) |

void | showEntireScene () |

void | fitSphere (const Vec ¢er, float radius) |

void | fitBoundingBox (const Vec &min, const Vec &max) |

void | fitScreenRegion (const QRect &rectangle) |

void | centerScene () |

void | interpolateToZoomOnPixel (const QPoint &pixel) |

void | interpolateToFitScene () |

void | interpolateTo (const Frame &fr, float duration) |

## Frustum | |

Type | type () const |

float | fieldOfView () const |

float | horizontalFieldOfView () const |

float | aspectRatio () const |

int | screenWidth () const |

int | screenHeight () const |

void | getViewport (GLint viewport[4]) const |

float | pixelGLRatio (const Vec &position) const |

float | zNearCoefficient () const |

float | zClippingCoefficient () const |

virtual float | zNear () const |

virtual float | zFar () const |

virtual void | getOrthoWidthHeight (GLdouble &halfWidth, GLdouble &halfHeight) const |

void | getFrustumPlanesCoefficients (GLdouble coef[6][4]) const |

void | setType (Type type) |

void | setFieldOfView (float fov) |

void | setHorizontalFieldOfView (float hfov) |

void | setFOVToFitScene () |

void | setAspectRatio (float aspect) |

void | setScreenWidthAndHeight (int width, int height) |

void | setZNearCoefficient (float coef) |

void | setZClippingCoefficient (float coef) |

## Scene radius and center | |

float | sceneRadius () const |

Vec | sceneCenter () const |

float | distanceToSceneCenter () const |

void | setSceneRadius (float radius) |

void | setSceneCenter (const Vec ¢er) |

bool | setSceneCenterFromPixel (const QPoint &pixel) |

void | setSceneBoundingBox (const Vec &min, const Vec &max) |

## Revolve Around Point | |

Vec | revolveAroundPoint () const |

void | setRevolveAroundPoint (const Vec &rap) |

bool | setRevolveAroundPointFromPixel (const QPoint &pixel) |

## Associated frame | |

ManipulatedCameraFrame * | frame () const |

void | setFrame (ManipulatedCameraFrame *const mcf) |

## KeyFramed paths | |

KeyFrameInterpolator * | keyFrameInterpolator (int i) const |

void | setKeyFrameInterpolator (int i, KeyFrameInterpolator *const kfi) |

virtual void | addKeyFrameToPath (int i) |

virtual void | playPath (int i) |

virtual void | deletePath (int i) |

virtual void | resetPath (int i) |

virtual void | drawAllPaths () |

## OpenGL matrices | |

virtual void | loadProjectionMatrix (bool reset=true) const |

virtual void | loadModelViewMatrix (bool reset=true) const |

void | computeProjectionMatrix () const |

void | computeModelViewMatrix () const |

virtual void | loadProjectionMatrixStereo (bool leftBuffer=true) const |

virtual void | loadModelViewMatrixStereo (bool leftBuffer=true) const |

void | getProjectionMatrix (GLdouble m[16]) const |

void | getModelViewMatrix (GLdouble m[16]) const |

void | getModelViewProjectionMatrix (GLdouble m[16]) const |

void | getProjectionMatrix (GLfloat m[16]) const |

void | getModelViewMatrix (GLfloat m[16]) const |

## Drawing | |

virtual void | draw (bool drawFarPlane=true, float scale=1.0) const |

static void | drawCamera (float scale=1.0, float aspectRatio=1.33, float fieldOfView=M_PI/4.0) |

## World to Camera coordinate systems conversions | |

Vec | cameraCoordinatesOf (const Vec &src) const |

Vec | worldCoordinatesOf (const Vec &src) const |

void | getCameraCoordinatesOf (const float src[3], float res[3]) const |

void | getWorldCoordinatesOf (const float src[3], float res[3]) const |

## 2D screen to 3D world coordinate systems conversions | |

Vec | projectedCoordinatesOf (const Vec &src, const Frame *frame=NULL) const |

Vec | unprojectedCoordinatesOf (const Vec &src, const Frame *frame=NULL) const |

void | getProjectedCoordinatesOf (const float src[3], float res[3], const Frame *frame=NULL) const |

void | getUnprojectedCoordinatesOf (const float src[3], float res[3], const Frame *frame=NULL) const |

void | convertClickToLine (const QPoint &pixel, Vec &orig, Vec &dir) const |

Vec | pointUnderPixel (const QPoint &pixel, bool &found) const |

## Fly speed | |

float | flySpeed () const |

void | setFlySpeed (float speed) |

## Stereo parameters | |

float | IODistance () const |

float | physicalDistanceToScreen () const |

float | physicalScreenWidth () const |

float | focusDistance () const |

void | setIODistance (float distance) |

void | setPhysicalDistanceToScreen (float distance) |

void | setPhysicalScreenWidth (float width) |

void | setFocusDistance (float distance) |

## XML representation | |

virtual QDomElement | domElement (const QString &name, QDomDocument &document) const |

virtual void | initFromDOMElement (const QDomElement &element) |

A perspective or orthographic camera.

A Camera defines some intrinsic parameters (fieldOfView(), position(), viewDirection(), upVector()...) and useful positioning tools that ease its placement (showEntireScene(), fitSphere(), lookAt()...). It exports its associated OpenGL projection and modelview matrices and can interactively be modified using the mouse.

The position() and orientation() of the Camera are defined by a ManipulatedCameraFrame (retrieved using frame()). These methods are just convenient wrappers to the equivalent Frame methods. This also means that the Camera frame() can be attached to a Frame::referenceFrame() which enables complex Camera setups.

Different displacements can be performed using the mouse. The list of possible actions is defined by the QGLViewer::MouseAction enum. Use QGLViewer::setMouseBinding() to attach a specific action to an arbitrary mouse button-state key binding. These actions are detailed in the mouse page.

The default button binding are: QGLViewer::ROTATE (left), QGLViewer::ZOOM (middle) and QGLViewer::TRANSLATE (right). With this configuration, the Camera *observes* a scene and rotates around its revolveAroundPoint(). You can switch between this mode and a fly mode using the QGLViewer::CAMERA_MODE (see QGLViewer::toggleCameraMode()) keyboard shortcut (default is 'Space').

The type() of the Camera can be Camera::ORTHOGRAPHIC or Camera::PERSPECTIVE (see Type()). fieldOfView() is meaningless with Camera::ORTHOGRAPHIC.

The near and far planes of the Camera are fitted to the scene and determined from QGLViewer::sceneRadius(), QGLViewer::sceneCenter() and zClippingCoefficient() by the zNear() and zFar() methods. Reasonable values on the scene extends hence have to be provided to the QGLViewer in order for the Camera to correctly display the scene. High level positioning methods also use this information (showEntireScene(), centerScene()...).

A Camera holds KeyFrameInterpolator that can be used to save Camera positions and paths. You can interactively addKeyFrameToPath() to a given path using the default `Alt+F`

[1-12] shortcuts. Use playPath() to make the Camera follow the path (default shortcut is F[1-12]). See the keyboard page for details on key customization.

Use cameraCoordinatesOf() and worldCoordinatesOf() to convert to and from the Camera frame() coordinate system. projectedCoordinatesOf() and unprojectedCoordinatesOf() will convert from screen to 3D coordinates. convertClickToLine() is very useful for analytical object selection.

Stereo display is possible on machines with quad buffer capabilities (with Camera::PERSPECTIVE type() only). Test the stereoViewer example to check.

A Camera can also be used outside of a QGLViewer or even without OpenGL for its coordinate system conversion capabilities. Note however that some of them explicitly rely on the presence of a Z-buffer.

Enumerates the two possible types of Camera.

See type() and setType(). This type mainly defines different Camera projection matrix (see loadProjectionMatrix()). Many other methods (pointUnderPixel(), convertClickToLine(), projectedCoordinatesOf(), pixelGLRatio()...) take this Type into account.

Camera::Camera | ( | ) |

Default constructor.

sceneCenter() is set to (0,0,0) and sceneRadius() is set to 1.0. type() is Camera::PERSPECTIVE, with a `M_PI/4`

fieldOfView().

See IODistance(), physicalDistanceToScreen(), physicalScreenWidth() and focusDistance() documentations for default stereo parameter values.

Definition at line 37 of file camera.cpp.

Camera::~Camera | ( | ) | ` [virtual]` |

Virtual destructor.

The frame() is deleted, but the different keyFrameInterpolator() are *not* deleted (in case they are shared).

Definition at line 85 of file camera.cpp.

Camera::Camera | ( | const Camera & | camera | ) |

Copy constructor. Performs a deep copy using operator=().

Definition at line 93 of file camera.cpp.

void Camera::addKeyFrameToPath | ( | int | i | ) | ` [virtual, slot]` |

Adds the current Camera position() and orientation() as a keyFrame to the path number `i`

.

This method can also be used if you simply want to save a Camera point of view (a path made of a single keyFrame). Use playPath() to make the Camera play the keyFrame path (resp. restore the point of view). Use deletePath() to clear the path.

The default keyboard shortcut for this method is Alt+F[1-12]. Set QGLViewer::pathKey() and QGLViewer::addKeyFrameKeyboardModifiers().

If you use directly this method and the keyFrameInterpolator(i) does not exist, a new one is created. Its KeyFrameInterpolator::interpolated() signal should then be connected to the QGLViewer::updateGL() slot (see setKeyFrameInterpolator()).

Definition at line 1562 of file camera.cpp.

float qglviewer::Camera::aspectRatio | ( | ) | const` [inline]` |

Returns the Camera aspect ratio defined by screenWidth() / screenHeight().

When the Camera is attached to a QGLViewer, these values and hence the aspectRatio() are automatically fitted to the viewer's window aspect ratio using setScreenWidthAndHeight().

Vec qglviewer::Camera::cameraCoordinatesOf | ( | const Vec & | src | ) | const` [inline]` |

Returns the Camera frame coordinates of a point `src`

defined in world coordinates.

worldCoordinatesOf() performs the inverse transformation.

Note that the point coordinates are simply converted in a different coordinate system. They are not projected on screen. Use projectedCoordinatesOf() for that.

void Camera::centerScene | ( | ) | ` [slot]` |

Moves the Camera so that its sceneCenter() is projected on the center of the window. The orientation() and fieldOfView() are unchanged.

Simply projects the current position on a line passing through sceneCenter(). See also showEntireScene().

Definition at line 939 of file camera.cpp.

void Camera::computeModelViewMatrix | ( | ) | const |

Computes the modelView matrix associated with the Camera's position() and orientation().

This matrix converts from the world coordinates system to the Camera coordinates system, so that coordinates can then be projected on screen using the projection matrix (see computeProjectionMatrix()).

Use getModelViewMatrix() to retrieve this matrix.

**Note:**- You must call this method if your Camera is not associated with a QGLViewer and is used for offscreen computations (using (un)projectedCoordinatesOf() for instance). loadModelViewMatrix() does it otherwise.

Definition at line 373 of file camera.cpp.

void Camera::computeProjectionMatrix | ( | ) | const |

Computes the projection matrix associated with the Camera.

If type() is Camera::PERSPECTIVE, defines a `GL_PROJECTION`

matrix similar to what would `gluPerspective()`

do using the fieldOfView(), window aspectRatio(), zNear() and zFar() parameters.

If type() is Camera::ORTHOGRAPHIC, the projection matrix is as what `glOrtho()`

would do. Frustum's width and height are set using getOrthoWidthHeight().

Both types use zNear() and zFar() to place clipping planes. These values are determined from sceneRadius() and sceneCenter() so that they best fit the scene size.

Use getProjectionMatrix() to retrieve this matrix. Overload loadProjectionMatrix() if you want your Camera to use an exotic projection matrix.

**Note:**- You must call this method if your Camera is not associated with a QGLViewer and is used for offscreen computations (using (un)projectedCoordinatesOf() for instance). loadProjectionMatrix() does it otherwise.

Definition at line 327 of file camera.cpp.

void Camera::convertClickToLine | ( | const QPoint & | pixel, |

Vec & | orig, |
||

Vec & | dir |
||

) | const |

Gives the coefficients of a 3D half-line passing through the Camera eye and pixel (x,y).

The origin of the half line (eye position) is stored in `orig`

, while `dir`

contains the properly oriented and normalized direction of the half line.

`x`

and `y`

are expressed in Qt format (origin in the upper left corner). Use screenHeight() - y to convert to OpenGL units.

This method is useful for analytical intersection in a selection method.

See the select example for an illustration.

Definition at line 1804 of file camera.cpp.

void Camera::deletePath | ( | int | i | ) | ` [virtual, slot]` |

Deletes the keyFrameInterpolator() of index `i`

.

Disconnect the keyFrameInterpolator() KeyFrameInterpolator::interpolated() signal before deleting the keyFrameInterpolator() if needed:

disconnect(camera()->keyFrameInterpolator(i), SIGNAL(interpolated()), this, SLOT(updateGL())); camera()->deletePath(i);

Definition at line 1614 of file camera.cpp.

float Camera::distanceToSceneCenter | ( | ) | const |

Returns the distance from the Camera center to sceneCenter(), projected along the Camera Z axis. Used by zNear() and zFar() to optimize the Z range.

Definition at line 280 of file camera.cpp.

QDomElement Camera::domElement | ( | const QString & | name, |

QDomDocument & | document |
||

) | const` [virtual]` |

Returns an XML `QDomElement`

that represents the Camera.

`name`

is the name of the QDomElement tag. `doc`

is the `QDomDocument`

factory used to create QDomElement.

Concatenates the Camera parameters, the ManipulatedCameraFrame::domElement() and the paths' KeyFrameInterpolator::domElement().

Use initFromDOMElement() to restore the Camera state from the resulting `QDomElement`

.

If you want to save the Camera state in a file, use:

QDomDocument document("myCamera"); doc.appendChild( myCamera->domElement("Camera", document) ); QFile f("myCamera.xml"); if (f.open(IO_WriteOnly)) { QTextStream out(&f); document.save(out, 2); }

Note that the QGLViewer::camera() is automatically saved by QGLViewer::saveStateToFile() when a QGLViewer is closed. Use QGLViewer::restoreStateFromFile() to restore it back.

Definition at line 1667 of file camera.cpp.

void Camera::draw | ( | bool | drawFarPlane = `true` , |

float | scale = `1.0` |
||

) | const` [virtual]` |

Draws a representation of the Camera in the 3D world.

The near and far planes are drawn as quads, the frustum is drawn using lines and the camera up vector is represented by an arrow to disambiguate the drawing. See the standardCamera example for an illustration.

Note that the current `glColor`

and `glPolygonMode`

are used to draw the near and far planes. See the frustumCulling example for an example of semi-transparent plane drawing. Similarly, the current `glLineWidth`

and `glColor`

is used to draw the frustum outline.

When `drawFarPlane`

is `false`

, only the near plane is drawn. `scale`

can be used to scale the drawing: a value of 1.0 (default) will draw the Camera's frustum at its actual size.

This method assumes that the `glMatrixMode`

is `GL_MODELVIEW`

and that the current ModelView matrix corresponds to the world coordinate system (as it is at the beginning of QGLViewer::draw()). The Camera is then correctly positioned and orientated.

**Note:**- The drawing of a QGLViewer's own QGLViewer::camera() should not be visible, but may create artefacts due to numerical imprecisions.

Definition at line 1857 of file camera.cpp.

void Camera::drawAllPaths | ( | ) | ` [virtual, slot]` |

Draws all the Camera paths defined by the keyFrameInterpolator().

Simply calls KeyFrameInterpolator::drawPath() for all the defined paths. The path color is the current `glColor()`

.

**Attention:**- The OpenGL state is modified by this method: see KeyFrameInterpolator::drawPath().

Definition at line 1630 of file camera.cpp.

void Camera::drawCamera | ( | float | scale = `1.0` , |

float | aspectRatio = `1.33` , |
||

float | fieldOfView = `M_PI/4.0` |
||

) | ` [static]` |

This method has been deprecated in libQGLViewer version 2.2.0

Definition at line 1831 of file camera.cpp.

float qglviewer::Camera::fieldOfView | ( | ) | const` [inline]` |

Returns the vertical field of view of the Camera (in radians).

Value is set using setFieldOfView(). Default value is pi/4 radians. This value is meaningless if the Camera type() is Camera::ORTHOGRAPHIC.

The field of view corresponds the one used in `gluPerspective`

(see manual). It sets the Y (vertical) aperture of the Camera. The X (horizontal) angle is inferred from the window aspect ratio (see aspectRatio() and horizontalFieldOfView()).

Use setFOVToFitScene() to adapt the fieldOfView() to a given scene.

void Camera::fitBoundingBox | ( | const Vec & | min, |

const Vec & | max |
||

) | ` [slot]` |

Moves the Camera so that the (world axis aligned) bounding box (`min`

, `max`

) is entirely visible, using fitSphere().

Definition at line 986 of file camera.cpp.

void Camera::fitScreenRegion | ( | const QRect & | rectangle | ) | ` [slot]` |

Moves the Camera so that the rectangular screen region defined by `rectangle`

(pixel units, with origin in the upper left corner) fits the screen.

The Camera is translated (its orientation() is unchanged) so that `rectangle`

is entirely visible. Since the pixel coordinates only define a *frustum* in 3D, it's the intersection of this frustum with a plane (orthogonal to the viewDirection() and passing through the sceneCenter()) that is used to define the 3D rectangle that is eventually fitted.

Definition at line 1000 of file camera.cpp.

void Camera::fitSphere | ( | const Vec & | center, |

float | radius |
||

) | ` [slot]` |

Moves the Camera so that the sphere defined by (`center`

, `radius`

) is visible and fits the window.

The Camera is simply translated along its viewDirection() so that the sphere fits the screen. Its orientation() and its fieldOfView() are unchanged.

You should therefore orientate the Camera before you call this method. See lookAt(), setOrientation() and setUpVector().

Definition at line 962 of file camera.cpp.

float qglviewer::Camera::flySpeed | ( | ) | const` [inline]` |

Returns the fly speed of the Camera.

Simply returns frame()->flySpeed(). See the ManipulatedCameraFrame::flySpeed() documentation. This value is only meaningful when the MouseAction bindings is QGLViewer::MOVE_FORWARD or QGLViewer::MOVE_BACKWARD.

Set to 1% of the sceneRadius() by setSceneRadius(). See also setFlySpeed().

float qglviewer::Camera::focusDistance | ( | ) | const` [inline]` |

Returns the focus distance used by stereo display, expressed in OpenGL units.

This is the distance in the virtual world between the Camera and the plane where the horizontal stereo parallax is null (the stereo left and right cameras' lines of sigth cross at this distance).

This distance is the virtual world equivalent of the real-world physicalDistanceToScreen().

**Attention:**- This value is modified by QGLViewer::setSceneRadius(), setSceneRadius() and setFieldOfView(). When one of these values is modified, focusDistance() is set to sceneRadius() / tan(fieldOfView()/2), which provides good results.

ManipulatedCameraFrame* qglviewer::Camera::frame | ( | ) | const` [inline]` |

Returns the ManipulatedCameraFrame attached to the Camera.

This ManipulatedCameraFrame defines its position() and orientation() and can translate mouse events into Camera displacement. Set using setFrame().

void Camera::getCameraCoordinatesOf | ( | const float | src[3], |

float | res[3] |
||

) | const |

Same as cameraCoordinatesOf(), but with `float`

[3] parameters (`src`

and `res`

may be identical pointers).

Definition at line 1339 of file camera.cpp.

void Camera::getFrustumPlanesCoefficients | ( | GLdouble | coef[6][4] | ) | const |

Returns the 6 plane equations of the Camera frustum.

The six 4-component vectors of `coef`

respectively correspond to the left, right, near, far, top and bottom Camera frustum planes. Each vector holds a plane equation of the form:

a*x + b*y + c*z + d = 0

where `a`

, `b`

, `c`

and `d`

are the 4 components of each vector, in that order.

See the frustumCulling example for an application.

This format is compatible with the `glClipPlane()`

function. One camera frustum plane can hence be applied in an other viewer to visualize the culling results:

// Retrieve plane equations GLdouble coef[6][4]; mainViewer->camera()->getFrustumPlanesCoefficients(coef); // These two additional clipping planes (which must have been enabled) // will reproduce the mainViewer's near and far clipping. glClipPlane(GL_CLIP_PLANE0, coef[2]); glClipPlane(GL_CLIP_PLANE1, coef[3]);

Definition at line 1985 of file camera.cpp.

void Camera::getModelViewMatrix | ( | GLdouble | m[16] | ) | const |

Fills `m`

with the Camera modelView matrix values.

First calls computeModelViewMatrix() to define the Camera modelView matrix.

Note that this matrix is usually *not* the one you would get from a `glGetDoublev(GL_MODELVIEW_MATRIX, m)`

. It actually represents the state of the `GL_MODELVIEW`

after QGLViewer::preDraw(), at the beginning of QGLViewer::draw(). It converts from the world to the Camera coordinate system. As soon as you modify the `GL_MODELVIEW`

in your QGLViewer::draw() method, the two matrices differ.

The result is an OpenGL 4x4 matrix, which is given in *column-major* order (see `glMultMatrix`

man page for details).

See also getProjectionMatrix() and setFromModelViewMatrix().

Definition at line 612 of file camera.cpp.

void Camera::getModelViewMatrix | ( | GLfloat | m[16] | ) | const |

Definition at line 653 of file camera.cpp.

void Camera::getModelViewProjectionMatrix | ( | GLdouble | m[16] | ) | const |

Fills `m`

with the product of the ModelView and Projection matrices.

Calls getModelViewMatrix() and getProjectionMatrix() and then fills `m`

with the product of these two matrices.

Definition at line 624 of file camera.cpp.

void Camera::getOrthoWidthHeight | ( | GLdouble & | halfWidth, |

GLdouble & | halfHeight |
||

) | const` [virtual]` |

Returns the `halfWidth`

and `halfHeight`

of the Camera orthographic frustum.

These values are only valid and used when the Camera is of type() Camera::ORTHOGRAPHIC. They are expressed in OpenGL units and are used by loadProjectionMatrix() to define the projection matrix using:

These values are proportional to the Camera (z projected) distance to the revolveAroundPoint(). When zooming on the object, the Camera is translated forward *and* its frustum is narrowed, making the object appear bigger on screen, as intuitively expected.

Overload this method to change this behavior if desired, as is done in the standardCamera example.

Definition at line 301 of file camera.cpp.

void Camera::getProjectedCoordinatesOf | ( | const float | src[3], |

float | res[3], |
||

const Frame * | frame = `NULL` |
||

) | const |

Same as projectedCoordinatesOf(), but with `float`

parameters (`src`

and `res`

can be identical pointers).

Definition at line 1496 of file camera.cpp.

void Camera::getProjectionMatrix | ( | GLdouble | m[16] | ) | const |

Fills `m`

with the Camera projection matrix values.

Calls computeProjectionMatrix() to define the Camera projection matrix.

This matrix only reflects the Camera's internal parameters and it may differ from the `GL_PROJECTION`

matrix retrieved using `glGetDoublev(GL_PROJECTION_MATRIX, m)`

. It actually represents the state of the `GL_PROJECTION`

after QGLViewer::preDraw(), at the beginning of QGLViewer::draw(). If you modified the `GL_PROJECTION`

matrix (for instance using QGLViewer::startScreenCoordinatesSystem()), the two results differ.

The result is an OpenGL 4x4 matrix, which is given in *column-major* order (see `glMultMatrix`

man page for details).

See also getModelViewMatrix() and setFromProjectionMatrix().

Definition at line 590 of file camera.cpp.

void Camera::getProjectionMatrix | ( | GLfloat | m[16] | ) | const |

Definition at line 644 of file camera.cpp.

void Camera::getUnprojectedCoordinatesOf | ( | const float | src[3], |

float | res[3], |
||

const Frame * | frame = `NULL` |
||

) | const |

Same as unprojectedCoordinatesOf(), but with `float`

parameters (`src`

and `res`

can be identical pointers).

Definition at line 1504 of file camera.cpp.

void Camera::getViewport | ( | GLint | viewport[4] | ) | const |

Fills `viewport`

with the Camera OpenGL viewport.

This method is mainly used in conjunction with `gluProject`

, which requires such a viewport. Returned values are (0, screenHeight(), screenWidth(), - screenHeight()), so that the origin is located in the *upper* left corner of the window (Qt style coordinate system).

Definition at line 1359 of file camera.cpp.

void Camera::getWorldCoordinatesOf | ( | const float | src[3], |

float | res[3] |
||

) | const |

Same as worldCoordinatesOf(), but with `float`

[3] parameters (`src`

and `res`

may be identical pointers).

Definition at line 1347 of file camera.cpp.

float qglviewer::Camera::horizontalFieldOfView | ( | ) | const` [inline]` |

Returns the horizontal field of view of the Camera (in radians).

Value is set using setHorizontalFieldOfView() or setFieldOfView(). These values are always linked by:

horizontalFieldOfView() = 2.0 * atan ( tan(fieldOfView()/2.0) * aspectRatio() ).

void Camera::initFromDOMElement | ( | const QDomElement & | element | ) | ` [virtual, slot]` |

Restores the Camera state from a `QDomElement`

created by domElement().

Use the following code to retrieve a Camera state from a file created using domElement():

// Load DOM from file QDomDocument document; QFile f("myCamera.xml"); if (f.open(IO_ReadOnly)) { document.setContent(&f); f.close(); } // Parse the DOM tree QDomElement main = document.documentElement(); myCamera->initFromDOMElement(main);

The frame() pointer is not modified by this method. The frame() state is however modified.

**Attention:**- The original keyFrameInterpolator() are deleted and should be copied first if they are shared.

Definition at line 1729 of file camera.cpp.

void Camera::interpolateTo | ( | const Frame & | fr, |

float | duration |
||

) | ` [slot]` |

Smoothly interpolates the Camera on a KeyFrameInterpolator path so that it goes to `fr`

.

`fr`

is expressed in world coordinates. `duration`

tunes the interpolation speed (default is 1 second).

See also interpolateToFitScene() and interpolateToZoomOnPixel().

Definition at line 884 of file camera.cpp.

void Camera::interpolateToFitScene | ( | ) | ` [slot]` |

Interpolates the Camera on a one second KeyFrameInterpolator path so that the entire scene fits the screen at the end.

The scene is defined by its sceneCenter() and its sceneRadius(). See showEntireScene().

The orientation() of the Camera is not modified. See also interpolateToZoomOnPixel().

Definition at line 855 of file camera.cpp.

void Camera::interpolateToZoomOnPixel | ( | const QPoint & | pixel | ) | ` [slot]` |

Makes the Camera smoothly zoom on the pointUnderPixel() `pixel`

.

Nothing happens if no pointUnderPixel() is found. Otherwise a KeyFrameInterpolator is created that animates the Camera on a one second path that brings the Camera closer to the point under `pixel`

.

See also interpolateToFitScene().

Definition at line 817 of file camera.cpp.

float qglviewer::Camera::IODistance | ( | ) | const` [inline]` |

Returns the user's inter-ocular distance (in meters). Default value is 0.062m, which fits most people.

loadProjectionMatrixStereo() uses this value to define the Camera offset and frustum. See setIODistance().

KeyFrameInterpolator * Camera::keyFrameInterpolator | ( | int | i | ) | const |

Returns the KeyFrameInterpolator that defines the Camera path number `i`

.

If path `i`

is not defined for this index, the method returns a `NULL`

pointer.

Definition at line 1516 of file camera.cpp.

void Camera::loadModelViewMatrix | ( | bool | reset = `true` | ) | const` [virtual]` |

Loads the OpenGL `GL_MODELVIEW`

matrix with the modelView matrix corresponding to the Camera.

Calls computeModelViewMatrix() to compute the Camera's modelView matrix.

This method is used by QGLViewer::preDraw() (called before user's QGLViewer::draw() method) to set the `GL_MODELVIEW`

matrix according to the viewer's QGLViewer::camera() position() and orientation().

As a result, the vertices used in QGLViewer::draw() can be defined in the so called world coordinate system. They are multiplied by this matrix to get converted to the Camera coordinate system, before getting projected using the `GL_PROJECTION`

matrix (see loadProjectionMatrix()).

When `reset`

is `true`

(default), the method loads (overwrites) the `GL_MODELVIEW`

matrix. Setting `reset`

to `false`

simply calls `glMultMatrixd`

(might be useful for some applications).

Overload this method or simply call glLoadMatrixd() at the beginning of QGLViewer::draw() if you want your Camera to use an exotic modelView matrix. See also loadProjectionMatrix().

getModelViewMatrix() returns the 4x4 modelView matrix.

**Attention:**- glMatrixMode is set to
`GL_MODELVIEW`

- If you use several OpenGL contexts and bypass the Qt main refresh loop, you should call QGLWidget::makeCurrent() before this method in order to activate the right OpenGL context.

Definition at line 469 of file camera.cpp.

void Camera::loadModelViewMatrixStereo | ( | bool | leftBuffer = `true` | ) | const` [virtual]` |

Same as loadModelViewMatrix() but for a stereo setup.

Only the Camera::PERSPECTIVE type() is supported for stereo mode. See QGLViewer::setStereoDisplay().

The modelView matrix is almost identical to the mono-vision one. It is simply translated along its horizontal axis by a value that depends on stereo parameters (see focusDistance(), IODistance(), and physicalScreenWidth()).

When `leftBuffer`

is `true`

, computes the modelView matrix associated to the left eye (right eye otherwise).

loadProjectionMatrixStereo() explains how to retrieve to resulting matrix.

See the stereoViewer and the anaglyph examples for an illustration.

**Attention:**- glMatrixMode is set to
`GL_MODELVIEW`

.

Definition at line 560 of file camera.cpp.

void Camera::loadProjectionMatrix | ( | bool | reset = `true` | ) | const` [virtual]` |

Loads the OpenGL `GL_PROJECTION`

matrix with the Camera projection matrix.

The Camera projection matrix is computed using computeProjectionMatrix().

When `reset`

is `true`

(default), the method clears the previous projection matrix by calling `glLoadIdentity`

before setting the matrix. Setting `reset`

to `false`

is useful for `GL_SELECT`

mode, to combine the pushed matrix with a picking matrix. See QGLViewer::beginSelection() for details.

This method is used by QGLViewer::preDraw() (called before user's QGLViewer::draw() method) to set the `GL_PROJECTION`

matrix according to the viewer's QGLViewer::camera() settings.

Use getProjectionMatrix() to retrieve this matrix. Overload this method if you want your Camera to use an exotic projection matrix. See also loadModelViewMatrix().

**Attention:**`glMatrixMode`

is set to`GL_PROJECTION`

.- If you use several OpenGL contexts and bypass the Qt main refresh loop, you should call QGLWidget::makeCurrent() before this method in order to activate the right OpenGL context.

Definition at line 432 of file camera.cpp.

void Camera::loadProjectionMatrixStereo | ( | bool | leftBuffer = `true` | ) | const` [virtual]` |

Same as loadProjectionMatrix() but for a stereo setup.

Only the Camera::PERSPECTIVE type() is supported for stereo mode. See QGLViewer::setStereoDisplay().

Uses focusDistance(), IODistance(), and physicalScreenWidth() to compute cameras offset and asymmetric frustums.

When `leftBuffer`

is `true`

, computes the projection matrix associated to the left eye (right eye otherwise). See also loadModelViewMatrixStereo().

See the stereoViewer and the anaglyph examples for an illustration.

To retrieve this matrix, use a code like:

glMatrixMode(GL_PROJECTION); glPushMatrix(); loadProjectionMatrixStereo(left_or_right); glGetFloatv(GL_PROJECTION_MATRIX, m); glPopMatrix();

Note that getProjectionMatrix() always returns the mono-vision matrix.

**Attention:**- glMatrixMode is set to
`GL_PROJECTION`

.

Definition at line 505 of file camera.cpp.

void Camera::lookAt | ( | const Vec & | target | ) | ` [slot]` |

Sets the Camera orientation(), so that it looks at point `target`

(defined in the world coordinate system).

The Camera position() is not modified. Simply setViewDirection().

See also setUpVector(), setOrientation(), showEntireScene(), fitSphere() and fitBoundingBox().

Definition at line 950 of file camera.cpp.

Equal operator.

All the parameters of `camera`

are copied. The frame() pointer is not modified, but its Frame::position() and Frame::orientation() are set to those of `camera`

.

**Attention:**- The Camera screenWidth() and screenHeight() are set to those of
`camera`

. If your Camera is associated with a QGLViewer, you should update these value after the call to this method:The same applies to sceneCenter() and sceneRadius(), if needed.*(camera()) = otherCamera; camera()->setScreenWidthAndHeight(width(), height());

Definition at line 123 of file camera.cpp.

Quaternion qglviewer::Camera::orientation | ( | ) | const` [inline]` |

Returns the Camera orientation, defined in the world coordinate system.

Actually returns `frame()->orientation()`

. Use setOrientation(), setUpVector() or lookAt() to set the Camera orientation.

float qglviewer::Camera::physicalDistanceToScreen | ( | ) | const` [inline]` |

Returns the physical distance between the user's eyes and the screen (in meters).

physicalDistanceToScreen() and focusDistance() represent the same distance. The former is expressed in physical real world units, while the latter is expressed in OpenGL virtual world units.

This is a helper function. It simply returns physicalScreenWidth() / 2.0 / tan(horizontalFieldOfView() / 2.0);

float qglviewer::Camera::physicalScreenWidth | ( | ) | const` [inline]` |

Returns the physical screen width, in meters. Default value is 0.5m (average monitor width).

Used for stereo display only (see loadModelViewMatrixStereo() and loadProjectionMatrixStereo()). Set using setPhysicalScreenWidth().

float Camera::pixelGLRatio | ( | const Vec & | position | ) | const |

Returns the ratio between pixel and OpenGL units at `position`

.

A line of `n`

* pixelGLRatio() OpenGL units, located at `position`

in the world coordinates system, will be projected with a length of `n`

pixels on screen.

Use this method to scale objects so that they have a constant pixel size on screen. The following code will draw a 20 pixel line, starting at sceneCenter() and always directed along the screen vertical direction:

glBegin(GL_LINES); glVertex3fv(sceneCenter()); glVertex3fv(sceneCenter() + 20 * pixelGLRatio(sceneCenter()) * camera()->upVector()); glEnd();

Definition at line 761 of file camera.cpp.

void Camera::playPath | ( | int | i | ) | ` [virtual, slot]` |

Makes the Camera follow the path of keyFrameInterpolator() number `i`

.

If the interpolation is started, it stops it instead.

This method silently ignores undefined (empty) paths (see keyFrameInterpolator()).

The default keyboard shortcut for this method is F[1-12]. Set QGLViewer::pathKey() and QGLViewer::playPathKeyboardModifiers().

Definition at line 1578 of file camera.cpp.

Vec Camera::pointUnderPixel | ( | const QPoint & | pixel, |

bool & | found |
||

) | const |

Returns the coordinates of the 3D point located at pixel (x,y) on screen.

Calls a `glReadPixel`

to get the pixel depth and applies an unprojectedCoordinatesOf() to the result. `found`

indicates whether a point was found or not (i.e. background pixel, result's depth is zFar() in that case).

`x`

and `y`

are expressed in pixel units with an origin in the upper left corner. Use screenHeight() - y to convert to OpenGL standard.

**Attention:**- This method assumes that a GL context is available, and that its content was drawn using the Camera (i.e. using its projection and modelview matrices). This method hence cannot be used for offscreen Camera computations. Use cameraCoordinatesOf() and worldCoordinatesOf() to perform similar operations in that case.

**Note:**- The precision of the z-Buffer highly depends on how the zNear() and zFar() values are fitted to your scene. Loose boundaries will result in imprecision along the viewing direction.

Definition at line 913 of file camera.cpp.

Vec qglviewer::Camera::position | ( | ) | const` [inline]` |

Returns the Camera position (the eye), defined in the world coordinate system.

Use setPosition() to set the Camera position. Other convenient methods are showEntireScene() or fitSphere(). Actually returns `frame()->position()`

.

This position corresponds to the projection center of a Camera::PERSPECTIVE Camera. It is not located in the image plane, which is at a zNear() distance ahead.

Vec Camera::projectedCoordinatesOf | ( | const Vec & | src, |

const Frame * | frame = `NULL` |
||

) | const |

Returns the screen projected coordinates of a point `src`

defined in the `frame`

coordinate system.

When `frame`

in `NULL`

(default), `src`

is expressed in the world coordinate system.

The x and y coordinates of the returned Vec are expressed in pixel, (0,0) being the *upper* left corner of the window. The z coordinate ranges between 0.0 (near plane) and 1.0 (excluded, far plane). See the `gluProject`

man page for details.

unprojectedCoordinatesOf() performs the inverse transformation.

See the screenCoordSystem example.

This method only uses the intrinsic Camera parameters (see getModelViewMatrix(), getProjectionMatrix() and getViewport()) and is completely independent of the OpenGL `GL_MODELVIEW`

, `GL_PROJECTION`

and viewport matrices. You can hence define a virtual Camera and use this method to compute projections out of a classical rendering context.

**Attention:**- However, if your Camera is not attached to a QGLViewer (used for offscreen computations for instance), make sure the Camera matrices are updated before calling this method. Call computeModelViewMatrix() and computeProjectionMatrix() to do so.

If you call this method several times with no change in the matrices, consider precomputing the projection times modelview matrix to save computation time if required (`P`

x `M`

in the `gluProject`

man page).

Here is the code corresponding to what this method does (kindly submitted by Robert W. Kuhn) :

Vec project(Vec point) { GLint Viewport[4]; GLdouble Projection[16], Modelview[16]; GLdouble matrix[16]; // Precomputation begin glGetIntegerv(GL_VIEWPORT , Viewport); glGetDoublev (GL_MODELVIEW_MATRIX , Modelview); glGetDoublev (GL_PROJECTION_MATRIX, Projection); for (unsigned short m=0; m<4; ++m) { for (unsigned short l=0; l<4; ++l) { double sum = 0.0; for (unsigned short k=0; k<4; ++k) sum += Projection[l+4*k]*Modelview[k+4*m]; matrix[l+4*m] = sum; } } // Precomputation end GLdouble v[4], vs[4]; v[0]=point[0]; v[1]=point[1]; v[2]=point[2]; v[3]=1.0; vs[0]=matrix[0 ]*v[0] + matrix[4 ]*v[1] + matrix[8 ]*v[2] + matrix[12 ]*v[3]; vs[1]=matrix[1 ]*v[0] + matrix[5 ]*v[1] + matrix[9 ]*v[2] + matrix[13 ]*v[3]; vs[2]=matrix[2 ]*v[0] + matrix[6 ]*v[1] + matrix[10]*v[2] + matrix[14 ]*v[3]; vs[3]=matrix[3 ]*v[0] + matrix[7 ]*v[1] + matrix[11]*v[2] + matrix[15 ]*v[3]; vs[0] /= vs[3]; vs[1] /= vs[3]; vs[2] /= vs[3]; vs[0] = vs[0] * 0.5 + 0.5; vs[1] = vs[1] * 0.5 + 0.5; vs[2] = vs[2] * 0.5 + 0.5; vs[0] = vs[0] * Viewport[2] + Viewport[0]; vs[1] = vs[1] * Viewport[3] + Viewport[1]; return Vec(vs[0], Viewport[3]-vs[1], vs[2]); }

Definition at line 1441 of file camera.cpp.

void Camera::resetPath | ( | int | i | ) | ` [virtual, slot]` |

Resets the path of the keyFrameInterpolator() number `i`

.

If this path is *not* being played (see playPath() and KeyFrameInterpolator::interpolationIsStarted()), resets it to its starting position (see KeyFrameInterpolator::resetInterpolation()). If the path is played, simply stops interpolation.

Definition at line 1593 of file camera.cpp.

Vec qglviewer::Camera::revolveAroundPoint | ( | ) | const` [inline]` |

The point the Camera revolves around with the QGLViewer::ROTATE mouse binding. Defined in world coordinate system.

Default value is the sceneCenter().

**Attention:**- setSceneCenter() changes this value.

Vec qglviewer::Camera::rightVector | ( | ) | const` [inline]` |

Returns the normalized right vector of the Camera, defined in the world coordinate system.

This vector lies in the Camera horizontal plane, directed along the X axis (orthogonal to upVector() and to viewDirection()). Set using setUpVector(), lookAt() or setOrientation().

Simply returns frame()->inverseTransformOf(Vec(1.0, 0.0, 0.0)).

Vec qglviewer::Camera::sceneCenter | ( | ) | const` [inline]` |

Returns the position of the scene center, defined in the world coordinate system.

The scene observed by the Camera should be roughly centered on this position, and included in a sceneRadius() sphere. This approximate description of the scene permits a zNear() and zFar() clipping planes definition, and allows convenient positioning methods such as showEntireScene().

Default value is (0,0,0) (world origin). Use setSceneCenter() to change it. See also setSceneBoundingBox().

Note that QGLViewer::sceneCenter() (resp. QGLViewer::setSceneCenter()) simply call this method (resp. setSceneCenter()) on its associated QGLViewer::camera().

float qglviewer::Camera::sceneRadius | ( | ) | const` [inline]` |

Returns the radius of the scene observed by the Camera.

You need to provide such an approximation of the scene dimensions so that the Camera can adapt its zNear() and zFar() values. See the sceneCenter() documentation.

See also setSceneBoundingBox().

Note that QGLViewer::sceneRadius() (resp. QGLViewer::setSceneRadius()) simply call this method (resp. setSceneRadius()) on its associated QGLViewer::camera().

int qglviewer::Camera::screenHeight | ( | ) | const` [inline]` |

int qglviewer::Camera::screenWidth | ( | ) | const` [inline]` |

void qglviewer::Camera::setAspectRatio | ( | float | aspect | ) | ` [inline, slot]` |

Defines the Camera aspectRatio().

This value is actually inferred from the screenWidth() / screenHeight() ratio. You should use setScreenWidthAndHeight() instead.

This method might however be convenient when the Camera is not associated with a QGLViewer. It actually sets the screenHeight() to 100 and the screenWidth() accordingly. See also setFOVToFitScene().

**Note:**- If you absolutely need an aspectRatio() that does not correspond to your viewer's window dimensions, overload loadProjectionMatrix() or multiply the created GL_PROJECTION matrix by a scaled diagonal matrix in your QGLViewer::draw() method.

void qglviewer::Camera::setFieldOfView | ( | float | fov | ) | ` [inline, slot]` |

Sets the vertical fieldOfView() of the Camera (in radians).

Note that focusDistance() is set to sceneRadius() / tan(fieldOfView()/2) by this method.

void qglviewer::Camera::setFlySpeed | ( | float | speed | ) | ` [inline, slot]` |

Sets the Camera flySpeed().

**Attention:**- This value is modified by setSceneRadius().

void qglviewer::Camera::setFocusDistance | ( | float | distance | ) | ` [inline, slot]` |

Sets the focusDistance(), in OpenGL scene units.

void Camera::setFOVToFitScene | ( | ) | ` [slot]` |

Changes the Camera fieldOfView() so that the entire scene (defined by QGLViewer::sceneCenter() and QGLViewer::sceneRadius()) is visible from the Camera position().

The position() and orientation() of the Camera are not modified and you first have to orientate the Camera in order to actually see the scene (see lookAt(), showEntireScene() or fitSphere()).

This method is especially useful for *shadow* *maps* computation. Use the Camera positioning tools (setPosition(), lookAt()) to position a Camera at the light position. Then use this method to define the fieldOfView() so that the shadow map resolution is optimally used:

// The light camera needs size hints in order to optimize its fieldOfView lightCamera->setSceneRadius(sceneRadius()); lightCamera->setSceneCenter(sceneCenter()); // Place the light camera. lightCamera->setPosition(lightFrame->position()); lightCamera->lookAt(sceneCenter()); lightCamera->setFOVToFitScene();

See the (soon available) shadowMap contribution example for a practical implementation.

**Attention:**- The fieldOfView() is clamped to M_PI/2.0. This happens when the Camera is at a distance lower than sqrt(2.0) * sceneRadius() from the sceneCenter(). It optimizes the shadow map resolution, although it may miss some parts of the scene.

Definition at line 803 of file camera.cpp.

void Camera::setFrame | ( | ManipulatedCameraFrame *const | mcf | ) | ` [slot]` |

If you want to move the Camera, use setPosition() and setOrientation() or one of the Camera positioning methods (lookAt(), fitSphere(), showEntireScene()...) instead.

If you want to save the Camera position(), there's no need to call this method either. Use addKeyFrameToPath() and playPath() instead.

This method is actually mainly useful if you derive the ManipulatedCameraFrame class and want to use an instance of your new class to move the Camera.

A `NULL`

`mcf`

pointer will silently be ignored. The calling method is responsible for deleting the previous frame() pointer if needed in order to prevent memory leaks.

Definition at line 269 of file camera.cpp.

void Camera::setFromModelViewMatrix | ( | const GLdouble *const | modelViewMatrix | ) |

Sets the Camera's position() and orientation() from an OpenGL ModelView matrix.

This enables a Camera initialisation from an other OpenGL application. `modelView`

is a 16 GLdouble vector representing a valid OpenGL ModelView matrix, such as one can get using:

GLdouble mvm[16]; glGetDoublev(GL_MODELVIEW_MATRIX, mvm); myCamera->setFromModelViewMatrix(mvm);

After this method has been called, getModelViewMatrix() returns a matrix equivalent to `modelView`

.

Only the orientation() and position() of the Camera are modified.

**Note:**- If you defined your matrix as
`GLdouble`

`mvm`

[4][4], pass`&`

(mvm[0][0]) as a parameter.

Definition at line 1151 of file camera.cpp.

void Camera::setFromProjectionMatrix | ( | const float | matrix[12] | ) |

Defines the Camera position(), orientation() and fieldOfView() from a projection matrix.

`matrix`

has to be given in the format used by vision algorithm. It has 3 lines and 4 columns. It transforms a point from the world homogeneous coordinate system (4 coordinates: `sx`

, `sy`

, `sz`

and `s`

) into a point in the screen homogeneous coordinate system (3 coordinates: `sx`

, `sy`

, and `s`

, where `x`

and `y`

are the pixel coordinates on the screen).

Its three lines correspond to the homogeneous coordinates of the normals to the planes x=0, y=0 and z=0, defined in the Camera coordinate system.

The elements of the matrix are ordered in line major order: you can call `setFromProjectionMatrix`

(&(matrix[0][0])) if you defined your matrix as a `float`

`matrix`

[3][4].

**Attention:**- Passing the result of getProjectionMatrix() or getModelViewMatrix() to this method is not possible (purposefully incompatible matrix dimensions).
`matrix`

is more likely to be the product of these two matrices, without the last line.

Use setFromModelViewMatrix() to set position() and orientation() from a `GL_MODELVIEW`

matrix. fieldOfView() can also be retrieved from a *perspective* `GL_PROJECTION`

matrix using 2.0 * atan(1.0/projectionMatrix[5]).

This code was written by Sylvain Paris.

Definition at line 1189 of file camera.cpp.

void qglviewer::Camera::setHorizontalFieldOfView | ( | float | hfov | ) | ` [inline, slot]` |

Sets the horizontalFieldOfView() of the Camera (in radians).

horizontalFieldOfView() and fieldOfView() are linked by the aspectRatio(). This method actually calls setFieldOfView(( 2.0 * atan (tan(hfov / 2.0) / aspectRatio()) )) so that a call to horizontalFieldOfView() returns the expected value.

void qglviewer::Camera::setIODistance | ( | float | distance | ) | ` [inline, slot]` |

Sets the IODistance().

void Camera::setKeyFrameInterpolator | ( | int | i, |

KeyFrameInterpolator *const | kfi |
||

) | ` [slot]` |

Sets the KeyFrameInterpolator that defines the Camera path of index `i`

.

The previous keyFrameInterpolator() is lost and should be deleted by the calling method if needed.

The KeyFrameInterpolator::interpolated() signal of `kfi`

probably needs to be connected to the Camera's associated QGLViewer::updateGL() slot, so that when the Camera position is interpolated using `kfi`

, every interpolation step updates the display:

myViewer.camera()->deletePath(3); myViewer.camera()->setKeyFrameInterpolator(3, myKeyFrameInterpolator); connect(myKeyFrameInterpolator, SIGNAL(interpolated()), myViewer, SLOT(updateGL());

**Note:**- These connections are done automatically when a Camera is attached to a QGLViewer, or when a new KeyFrameInterpolator is defined using the QGLViewer::addKeyFrameKeyboardModifiers() and QGLViewer::pathKey() (default is Alt+F[1-12]). See the keyboard page for details.

Definition at line 1542 of file camera.cpp.

void Camera::setOrientation | ( | const Quaternion & | q | ) | ` [slot]` |

Sets the Camera orientation(), defined in the world coordinate system.

Definition at line 1090 of file camera.cpp.

void Camera::setOrientation | ( | float | theta, |

float | phi |
||

) | ` [slot]` |

Sets the orientation() of the Camera using polar coordinates.

`theta`

rotates the Camera around its Y axis, and *then* `phi`

rotates it around its X axis. The polar coordinates are defined in the world coordinates system: `theta`

= `phi`

= 0 means that the Camera is directed towards the world Z axis. Both angles are expressed in radians.

See also setUpVector(). The position() of the Camera is unchanged, you may want to call showEntireScene() after this method to move the Camera.

This method can be useful to create Quicktime VR panoramic sequences, see the QGLViewer::saveSnapshot() documentation for details.

Definition at line 1080 of file camera.cpp.

void qglviewer::Camera::setPhysicalDistanceToScreen | ( | float | distance | ) | ` [inline, slot]` |

This method is deprecated. Use setPhysicalScreenWidth() instead.

void qglviewer::Camera::setPhysicalScreenWidth | ( | float | width | ) | ` [inline, slot]` |

void qglviewer::Camera::setPosition | ( | const Vec & | pos | ) | ` [inline, slot]` |

Sets the Camera position() (the eye), defined in the world coordinate system.

void Camera::setRevolveAroundPoint | ( | const Vec & | rap | ) | ` [slot]` |

Changes the revolveAroundPoint() to `rap`

(defined in the world coordinate system).

Definition at line 715 of file camera.cpp.

bool Camera::setRevolveAroundPointFromPixel | ( | const QPoint & | pixel | ) | ` [slot]` |

The revolveAroundPoint() is set to the point located under `pixel`

on screen.

Returns `true`

if a pointUnderPixel() was found. If no point was found under `pixel`

, the revolveAroundPoint() is left unchanged.

`pixel`

is expressed in Qt format (origin in the upper left corner of the window). See pointUnderPixel().

See also setSceneCenterFromPixel().

Definition at line 738 of file camera.cpp.

void Camera::setSceneBoundingBox | ( | const Vec & | min, |

const Vec & | max |
||

) | ` [slot]` |

Similar to setSceneRadius() and setSceneCenter(), but the scene limits are defined by a (world axis aligned) bounding box.

Definition at line 684 of file camera.cpp.

void Camera::setSceneCenter | ( | const Vec & | center | ) | ` [slot]` |

Sets the sceneCenter().

**Attention:**- This method also sets the revolveAroundPoint() to sceneCenter().

Definition at line 694 of file camera.cpp.

bool Camera::setSceneCenterFromPixel | ( | const QPoint & | pixel | ) | ` [slot]` |

setSceneCenter() to the result of pointUnderPixel(`pixel`

).

Returns `true`

if a pointUnderPixel() was found and sceneCenter() was actually changed.

See also setRevolveAroundPointFromPixel(). See the pointUnderPixel() documentation.

Definition at line 705 of file camera.cpp.

void Camera::setSceneRadius | ( | float | radius | ) | ` [slot]` |

Sets the sceneRadius() value. Negative values are ignored.

**Attention:**- This methods also sets focusDistance() to sceneRadius() / tan(fieldOfView()/2) and flySpeed() to 1% of sceneRadius().

Definition at line 667 of file camera.cpp.

void Camera::setScreenWidthAndHeight | ( | int | width, |

int | height |
||

) | ` [slot]` |

Sets Camera screenWidth() and screenHeight() (expressed in pixels).

You should not call this method when the Camera is associated with a QGLViewer, since the latter automatically updates these values when it is resized (hence overwritting your values).

Non-positive dimension are silently replaced by a 1 pixel value to ensure frustrum coherence.

If your Camera is used without a QGLViewer (offscreen rendering, shadow maps), use setAspectRatio() instead to define the projection matrix.

Definition at line 164 of file camera.cpp.

void Camera::setType | ( | Type | type | ) | ` [slot]` |

Changing the camera Type alters the viewport and the objects' size can be changed. This method garantees that the two frustum match in a plane normal to viewDirection(), passing through the Revolve Around Point (RAP).

Prefix the type with `Camera`

if needed, as in:

camera()->setType(Camera::ORTHOGRAPHIC); // or even qglviewer::Camera::ORTHOGRAPHIC if you do not use namespace

Definition at line 246 of file camera.cpp.

void Camera::setUpVector | ( | const Vec & | up, |

bool | noMove = `true` |
||

) | ` [slot]` |

Rotates the Camera so that its upVector() becomes `up`

(defined in the world coordinate system).

The Camera is rotated around an axis orthogonal to `up`

and to the current upVector() direction. Use this method in order to define the Camera horizontal plane.

When `noMove`

is set to `false`

, the orientation modification is compensated by a translation, so that the revolveAroundPoint() stays projected at the same position on screen. This is especially useful when the Camera is an observer of the scene (default mouse binding).

When `noMove`

is `true`

(default), the Camera position() is left unchanged, which is an intuitive behavior when the Camera is in a walkthrough fly mode (see the QGLViewer::MOVE_FORWARD and QGLViewer::MOVE_BACKWARD QGLViewer::MouseAction).

See also setViewDirection(), lookAt() and setOrientation().

Definition at line 1056 of file camera.cpp.

void Camera::setViewDirection | ( | const Vec & | direction | ) | ` [slot]` |

Rotates the Camera so that its viewDirection() is `direction`

(defined in the world coordinate system).

The Camera position() is not modified. The Camera is rotated so that the horizon (defined by its upVector()) is preserved. See also lookAt() and setUpVector().

Definition at line 1101 of file camera.cpp.

void qglviewer::Camera::setZClippingCoefficient | ( | float | coef | ) | ` [inline, slot]` |

Sets the zClippingCoefficient() value.

void qglviewer::Camera::setZNearCoefficient | ( | float | coef | ) | ` [inline, slot]` |

Sets the zNearCoefficient() value.

void Camera::showEntireScene | ( | ) | ` [slot]` |

Moves the Camera so that the entire scene is visible.

Simply calls fitSphere() on a sphere defined by sceneCenter() and sceneRadius().

You will typically use this method in QGLViewer::init() after you defined a new sceneRadius().

Definition at line 929 of file camera.cpp.

Type qglviewer::Camera::type | ( | ) | const` [inline]` |

Returns the Camera::Type of the Camera.

Set by setType(). Mainly used by loadProjectionMatrix().

A Camera::PERSPECTIVE Camera uses a classical projection mainly defined by its fieldOfView().

With a Camera::ORTHOGRAPHIC type(), the fieldOfView() is meaningless and the width and height of the Camera frustum are inferred from the distance to the revolveAroundPoint() using getOrthoWidthHeight().

Both types use zNear() and zFar() (to define their clipping planes) and aspectRatio() (for frustum shape).

Vec Camera::unprojectedCoordinatesOf | ( | const Vec & | src, |

const Frame * | frame = `NULL` |
||

) | const |

Returns the world unprojected coordinates of a point `src`

defined in the screen coordinate system.

The `src.x`

and `src.y`

input values are expressed in pixels, (0,0) being the *upper* left corner of the window. `src.z`

is a depth value ranging in [0..1[ (near and far plane respectively). See the `gluUnProject`

man page for details.

The result is expressed in the `frame`

coordinate system. When `frame`

is `NULL`

(default), the result is expressed in the world coordinates system. The possible `frame`

Frame::referenceFrame() are taken into account.

projectedCoordinatesOf() performs the inverse transformation.

This method only uses the intrinsic Camera parameters (see getModelViewMatrix(), getProjectionMatrix() and getViewport()) and is completely independent of the OpenGL `GL_MODELVIEW`

, `GL_PROJECTION`

and viewport matrices. You can hence define a virtual Camera and use this method to compute un-projections out of a classical rendering context.

**Attention:**- However, if your Camera is not attached to a QGLViewer (used for offscreen computations for instance), make sure the Camera matrices are updated before calling this method (use computeModelViewMatrix(), computeProjectionMatrix()). See also setScreenWidthAndHeight().

This method is not computationally optimized. If you call it several times with no change in the matrices, you should buffer the entire inverse projection matrix (modelview, projection and then viewport) to speed-up the queries. See the `gluUnProject`

man page for details.

Definition at line 1483 of file camera.cpp.

Vec qglviewer::Camera::upVector | ( | ) | const` [inline]` |

Returns the normalized up vector of the Camera, defined in the world coordinate system.

Set using setUpVector() or setOrientation(). It is orthogonal to viewDirection() and to rightVector().

It corresponds to the Y axis of the associated frame() (actually returns frame()->inverseTransformOf(Vec(0.0, 1.0, 0.0)) ).

Vec qglviewer::Camera::viewDirection | ( | ) | const` [inline]` |

Returns the normalized view direction of the Camera, defined in the world coordinate system.

Change this value using setViewDirection(), lookAt() or setOrientation(). It is orthogonal to upVector() and to rightVector().

This corresponds to the negative Z axis of the frame() ( frame()->inverseTransformOf(Vec(0.0, 0.0, -1.0)) ).

Vec qglviewer::Camera::worldCoordinatesOf | ( | const Vec & | src | ) | const` [inline]` |

Returns the world coordinates of the point whose position `src`

is defined in the Camera coordinate system.

cameraCoordinatesOf() performs the inverse transformation.

float qglviewer::Camera::zClippingCoefficient | ( | ) | const` [inline]` |

Returns the coefficient used to position the near and far clipping planes.

The near (resp. far) clipping plane is positioned at a distance equal to zClippingCoefficient() * sceneRadius() in front of (resp. behind) the sceneCenter(). This garantees an optimal use of the z-buffer range and minimizes aliasing. See the zNear() and zFar() documentations.

Default value is square root of 3.0 (so that a cube of size sceneRadius() is not clipped).

However, since the sceneRadius() is used for other purposes (see showEntireScene(), flySpeed(), ...) and you may want to change this value to define more precisely the location of the clipping planes. See also zNearCoefficient().

For a total control on clipping planes' positions, an other option is to overload the zNear() and zFar() methods. See the standardCamera example.

**Attention:**- When QGLViewer::cameraPathAreEdited(), this value is set to 5.0 so that the Camera paths are not clipped. The previous zClippingCoefficient() value is restored back when you leave this mode.

float Camera::zFar | ( | ) | const` [virtual]` |

Returns the far clipping plane distance used by the Camera projection matrix.

The far clipping plane is positioned at a distance equal to zClippingCoefficient() * sceneRadius() behind the sceneCenter():

zFar = distanceToSceneCenter() + zClippingCoefficient()*sceneRadius();

See the zNear() documentation for details.

Definition at line 232 of file camera.cpp.

float Camera::zNear | ( | ) | const` [virtual]` |

Returns the near clipping plane distance used by the Camera projection matrix.

The clipping planes' positions depend on the sceneRadius() and sceneCenter() rather than being fixed small-enough and large-enough values. A good scene dimension approximation will hence result in an optimal precision of the z-buffer.

The near clipping plane is positioned at a distance equal to zClippingCoefficient() * sceneRadius() in front of the sceneCenter():

In order to prevent negative or too small zNear() values (which would degrade the z precision), zNearCoefficient() is used when the Camera is inside the sceneRadius() sphere:

const float zMin = zNearCoefficient() * zClippingCoefficient() * sceneRadius(); if (zNear < zMin) zNear = zMin; // With an ORTHOGRAPHIC type, the value is simply clamped to 0.0

See also the zFar(), zClippingCoefficient() and zNearCoefficient() documentations.

If you need a completely different zNear computation, overload the zNear() and zFar() methods in a new class that publicly inherits from Camera and use QGLViewer::setCamera():

class myCamera :: public qglviewer::Camera { virtual float Camera::zNear() const { return 0.001; }; virtual float Camera::zFar() const { return 100.0; }; }

See the standardCamera example for an application.

**Attention:**- The value is always positive although the clipping plane is positioned at a negative z value in the Camera coordinate system. This follows the
`gluPerspective`

standard.

Definition at line 208 of file camera.cpp.

float qglviewer::Camera::zNearCoefficient | ( | ) | const` [inline]` |

Returns the coefficient which is used to set zNear() when the Camera is inside the sphere defined by sceneCenter() and zClippingCoefficient() * sceneRadius().

In that case, the zNear() value is set to zNearCoefficient() * zClippingCoefficient() * sceneRadius(). See the zNear() documentation for details.

Default value is 0.005, which is appropriate for most applications. In case you need a high dynamic ZBuffer precision, you can increase this value (~0.1). A lower value will prevent clipping of very close objects at the expense of a worst Z precision.

Only meaningful when Camera type is Camera::PERSPECTIVE.

float qglviewer::Camera::fieldOfView_` [private]` |

float qglviewer::Camera::focusDistance_` [private]` |

ManipulatedCameraFrame* qglviewer::Camera::frame_` [private]` |

float qglviewer::Camera::IODistance_` [private]` |

QMap<int, KeyFrameInterpolator*> qglviewer::Camera::kfi_` [private]` |

GLdouble qglviewer::Camera::modelViewMatrix_[16]` [mutable, private]` |

float qglviewer::Camera::orthoCoef_` [private]` |

float qglviewer::Camera::physicalScreenWidth_` [private]` |

GLdouble qglviewer::Camera::projectionMatrix_[16]` [mutable, private]` |

Vec qglviewer::Camera::sceneCenter_` [private]` |

float qglviewer::Camera::sceneRadius_` [private]` |

int qglviewer::Camera::screenHeight_` [private]` |

int qglviewer::Camera::screenWidth_` [private]` |

Type qglviewer::Camera::type_` [private]` |

float qglviewer::Camera::zClippingCoef_` [private]` |

float qglviewer::Camera::zNearCoef_` [private]` |

The documentation for this class was generated from the following files: