StandardCamera Class Reference

Inheritance diagram for StandardCamera:

Public Member Functions
void	changeOrthoFrustumSize (int delta)
virtual void	getOrthoWidthHeight (GLdouble &halfWidth, GLdouble &halfHeight) const
	Returns the halfWidth and halfHeight of the Camera orthographic frustum.
virtual float	zFar () const
	Returns the far clipping plane distance used by the Camera projection matrix.
virtual float	zNear () const
	Returns the near clipping plane distance used by the Camera projection matrix.
Public Member Functions inherited from Camera
	Camera ()
	Default constructor.
	Camera (const Camera &camera)
	Copy constructor.
virtual	~Camera ()
	Virtual destructor.
Camera &	operator= (const Camera &camera)
	Equal operator.
Vec	position () const
	Returns the Camera position (the eye), defined in the world coordinate system.
Vec	upVector () const
	Returns the normalized up vector of the Camera, defined in the world coordinate system.
Vec	viewDirection () const
	Returns the normalized view direction of the Camera, defined in the world coordinate system.
Vec	rightVector () const
	Returns the normalized right vector of the Camera, defined in the world coordinate system.
Quaternion	orientation () const
	Returns the Camera orientation, defined in the world coordinate system.
void	setFromModelViewMatrix (const GLdouble *const modelViewMatrix)
	Sets the Camera's position() and orientation() from an OpenGL ModelView matrix.
void	setFromProjectionMatrix (const float matrix[12])
	Defines the Camera position(), orientation() and fieldOfView() from a projection matrix.
Type	type () const
	Returns the Camera::Type of the Camera.
float	fieldOfView () const
	Returns the vertical field of view of the Camera (in radians).
float	horizontalFieldOfView () const
	Returns the horizontal field of view of the Camera (in radians).
float	aspectRatio () const
	Returns the Camera aspect ratio defined by screenWidth() / screenHeight().
int	screenWidth () const
	Returns the width (in pixels) of the Camera screen.
int	screenHeight () const
	Returns the height (in pixels) of the Camera screen.
void	getViewport (GLint viewport[4]) const
	Fills viewport with the Camera OpenGL viewport.
float	pixelGLRatio (const Vec &position) const
	Returns the ratio between pixel and OpenGL units at position.
float	zNearCoefficient () const
	Returns the coefficient which is used to set zNear() when the Camera is inside the sphere defined by sceneCenter() and zClippingCoefficient() * sceneRadius().
float	zClippingCoefficient () const
	Returns the coefficient used to position the near and far clipping planes.
void	getFrustumPlanesCoefficients (GLdouble coef[6][4]) const
	Returns the 6 plane equations of the Camera frustum.
float	sceneRadius () const
	Returns the radius of the scene observed by the Camera.
Vec	sceneCenter () const
	Returns the position of the scene center, defined in the world coordinate system.
float	distanceToSceneCenter () const
	Returns the distance from the Camera center to sceneCenter(), projected along the Camera Z axis.
Vec	revolveAroundPoint () const
	The point the Camera revolves around with the QGLViewer::ROTATE mouse binding.
ManipulatedCameraFrame *	frame () const
	Returns the ManipulatedCameraFrame attached to the Camera.
KeyFrameInterpolator *	keyFrameInterpolator (int i) const
	Returns the KeyFrameInterpolator that defines the Camera path number i.
virtual void	loadProjectionMatrix (bool reset=true) const
	Loads the OpenGL GL_PROJECTION matrix with the Camera projection matrix.
virtual void	loadModelViewMatrix (bool reset=true) const
	Loads the OpenGL GL_MODELVIEW matrix with the modelView matrix corresponding to the Camera.
void	computeProjectionMatrix () const
	Computes the projection matrix associated with the Camera.
void	computeModelViewMatrix () const
	Computes the modelView matrix associated with the Camera's position() and orientation().
virtual void	loadProjectionMatrixStereo (bool leftBuffer=true) const
	Same as loadProjectionMatrix() but for a stereo setup.
virtual void	loadModelViewMatrixStereo (bool leftBuffer=true) const
	Same as loadModelViewMatrix() but for a stereo setup.
void	getProjectionMatrix (GLdouble m[16]) const
	Fills m with the Camera projection matrix values.
void	getModelViewMatrix (GLdouble m[16]) const
	Fills m with the Camera modelView matrix values.
void	getModelViewProjectionMatrix (GLdouble m[16]) const
	Fills m with the product of the ModelView and Projection matrices.
void	getProjectionMatrix (GLfloat m[16]) const
void	getModelViewMatrix (GLfloat m[16]) const
virtual void	draw (bool drawFarPlane=true, float scale=1.0) const
	Draws a representation of the Camera in the 3D world.
Vec	cameraCoordinatesOf (const Vec &src) const
	Returns the Camera frame coordinates of a point src defined in world coordinates.
Vec	worldCoordinatesOf (const Vec &src) const
	Returns the world coordinates of the point whose position src is defined in the Camera coordinate system.
void	getCameraCoordinatesOf (const float src[3], float res[3]) const
	Same as cameraCoordinatesOf(), but with float[3] parameters (src and res may be identical pointers).
void	getWorldCoordinatesOf (const float src[3], float res[3]) const
	Same as worldCoordinatesOf(), but with float[3] parameters (src and res may be identical pointers).
Vec	projectedCoordinatesOf (const Vec &src, const Frame *frame=NULL) const
	Returns the screen projected coordinates of a point src defined in the frame coordinate system.
Vec	unprojectedCoordinatesOf (const Vec &src, const Frame *frame=NULL) const
	Returns the world unprojected coordinates of a point src defined in the screen coordinate system.
void	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).
void	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).
void	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).
Vec	pointUnderPixel (const QPoint &pixel, bool &found) const
	Returns the coordinates of the 3D point located at pixel (x,y) on screen.
float	flySpeed () const
	Returns the fly speed of the Camera.
float	IODistance () const
	Returns the user's inter-ocular distance (in meters).
float	physicalDistanceToScreen () const
	Returns the physical distance between the user's eyes and the screen (in meters).
float	physicalScreenWidth () const
	Returns the physical screen width, in meters.
float	focusDistance () const
	Returns the focus distance used by stereo display, expressed in OpenGL units.
virtual QDomElement	domElement (const QString &name, QDomDocument &document) const
	Returns an XML QDomElement that represents the Camera.

Additional Inherited Members
Public Types inherited from Camera
enum	Type { PERSPECTIVE, ORTHOGRAPHIC }
	Enumerates the two possible types of Camera. More...
Public Slots inherited from Camera
void	setPosition (const Vec &pos)
	Sets the Camera position() (the eye), defined in the world coordinate system.
void	setOrientation (const Quaternion &q)
	Sets the Camera orientation(), defined in the world coordinate system.
void	setOrientation (float theta, float phi)
	Sets the orientation() of the Camera using polar coordinates.
void	setUpVector (const Vec &up, bool noMove=true)
	Rotates the Camera so that its upVector() becomes up (defined in the world coordinate system).
void	setViewDirection (const Vec &direction)
	Rotates the Camera so that its viewDirection() is direction (defined in the world coordinate system).
void	setType (Type type)
	Defines the Camera type().
void	setFieldOfView (float fov)
	Sets the vertical fieldOfView() of the Camera (in radians).
void	setHorizontalFieldOfView (float hfov)
	Sets the horizontalFieldOfView() of the Camera (in radians).
void	setFOVToFitScene ()
	Changes the Camera fieldOfView() so that the entire scene (defined by QGLViewer::sceneCenter() and QGLViewer::sceneRadius()) is visible from the Camera position().
void	setAspectRatio (float aspect)
	Defines the Camera aspectRatio().
void	setScreenWidthAndHeight (int width, int height)
	Sets Camera screenWidth() and screenHeight() (expressed in pixels).
void	setZNearCoefficient (float coef)
	Sets the zNearCoefficient() value.
void	setZClippingCoefficient (float coef)
	Sets the zClippingCoefficient() value.
void	setSceneRadius (float radius)
	Sets the sceneRadius() value.
void	setSceneCenter (const Vec &center)
	Sets the sceneCenter().
bool	setSceneCenterFromPixel (const QPoint &pixel)
	setSceneCenter() to the result of pointUnderPixel(pixel).
void	setSceneBoundingBox (const Vec &min, const Vec &max)
	Similar to setSceneRadius() and setSceneCenter(), but the scene limits are defined by a (world axis aligned) bounding box.
void	setRevolveAroundPoint (const Vec &rap)
	Changes the revolveAroundPoint() to rap (defined in the world coordinate system).
bool	setRevolveAroundPointFromPixel (const QPoint &pixel)
	The revolveAroundPoint() is set to the point located under pixel on screen.
void	setFrame (ManipulatedCameraFrame *const mcf)
	Sets the Camera frame().
void	setKeyFrameInterpolator (int i, KeyFrameInterpolator *const kfi)
	Sets the KeyFrameInterpolator that defines the Camera path of index i.
virtual void	addKeyFrameToPath (int i)
	Adds the current Camera position() and orientation() as a keyFrame to the path number i.
virtual void	playPath (int i)
	Makes the Camera follow the path of keyFrameInterpolator() number i.
virtual void	deletePath (int i)
	Deletes the keyFrameInterpolator() of index i.
virtual void	resetPath (int i)
	Resets the path of the keyFrameInterpolator() number i.
virtual void	drawAllPaths ()
	Draws all the Camera paths defined by the keyFrameInterpolator().
void	setFlySpeed (float speed)
	Sets the Camera flySpeed().
void	setIODistance (float distance)
	Sets the IODistance().
void	setPhysicalDistanceToScreen (float distance)
	Sets the physicalDistanceToScreen().
void	setPhysicalScreenWidth (float width)
	Sets the physical screen (monitor or projected wall) width (in meters).
void	setFocusDistance (float distance)
	Sets the focusDistance(), in OpenGL scene units.
virtual void	initFromDOMElement (const QDomElement &element)
	Restores the Camera state from a QDomElement created by domElement().
void	lookAt (const Vec &target)
	Sets the Camera orientation(), so that it looks at point target (defined in the world coordinate system).
void	showEntireScene ()
	Moves the Camera so that the entire scene is visible.
void	fitSphere (const Vec &center, float radius)
	Moves the Camera so that the sphere defined by (center, radius) is visible and fits the window.
void	fitBoundingBox (const Vec &min, const Vec &max)
	Moves the Camera so that the (world axis aligned) bounding box (min, max) is entirely visible, using fitSphere().
void	fitScreenRegion (const QRect &rectangle)
	Moves the Camera so that the rectangular screen region defined by rectangle (pixel units, with origin in the upper left corner) fits the screen.
void	centerScene ()
	Moves the Camera so that its sceneCenter() is projected on the center of the window.
void	interpolateToZoomOnPixel (const QPoint &pixel)
	Makes the Camera smoothly zoom on the pointUnderPixel() pixel.
void	interpolateToFitScene ()
	Interpolates the Camera on a one second KeyFrameInterpolator path so that the entire scene fits the screen at the end.
void	interpolateTo (const Frame &fr, float duration)
	Smoothly interpolates the Camera on a KeyFrameInterpolator path so that it goes to fr.
Static Public Member Functions inherited from Camera
static void	drawCamera (float scale=1.0, float aspectRatio=1.33, float fieldOfView=M_PI/4.0)
	This method has been deprecated in libQGLViewer version 2.2.0.

Detailed Description

Definition at line 326 of file renderworld.cpp.

Member Function Documentation

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

inlinevirtual

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:

glOrtho( -halfWidth, halfWidth, -halfHeight, halfHeight, zNear(), zFar() )

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.

Reimplemented from Camera.

Definition at line 344 of file renderworld.cpp.

References Camera::aspectRatio().

virtual float zFar ( ) const

inlinevirtual

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.

Reimplemented from Camera.

Definition at line 334 of file renderworld.cpp.

virtual float zNear ( ) const

inlinevirtual

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():

zNear = distanceToSceneCenter() - zClippingCoefficient()*sceneRadius();

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.

Reimplemented from Camera.

Definition at line 331 of file renderworld.cpp.

---

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

• worldsim/src/renderworld.cpp