A perspective or orthographic camera. More...

#include <easy3d/renderer/camera.h>

Public Types
enum	Type { PERSPECTIVE , ORTHOGRAPHIC }
	Enumerates the two possible types of Camera. More...

Public Member Functions
	Camera ()
	Default constructor.

virtual	~Camera ()
	Destructor.

	Camera (const Camera &camera)
	Copy constructor.

Camera &	operator= (const Camera &camera)
	Assignment operator.

Position and orientation
vec3	position () const
	Get the position of the camera.

vec3	upVector () const
	Get the up vector of the camera.

vec3	viewDirection () const
	Get the view direction of the camera.

vec3	rightVector () const
	Get the right vector of the camera.

quat	orientation () const
	Get the orientation of the camera.

void	set_from_model_view_matrix (const mat4 &mv) const
	Sets the Camera's position() and orientation() from an OpenGL ModelView matrix.

void	set_from_calibration (float fx, float fy, float skew, float cx, float cy, const mat3 &R, const vec3 &t, bool convert=true)
	Defines the position(), orientation() and fieldOfView() of the camera from calibrated camera intrinsic and extrinsic parameters. This function assumes the camera parameters were obtained by standard camera calibration, in which image coordinates are denoted in pixels, with the origin point (0, 0) corresponding to the top-left corner of the image. The X axis starts at the left edge of an image and goes towards the right edge. The Y axis starts at the top of the image towards image bottom. All image pixels have non-negative coordinates.

void	set_from_calibration (const mat34 &proj)
	Defines the position(), orientation() and fieldOfView() of the camera from calibrated camera intrinsic and extrinsic parameters. This function assumes the camera parameters were obtained by standard camera calibration, in which image coordinates are denoted in pixels, with the origin point (0, 0) corresponding to the top-left corner of the image. The X axis starts at the left edge of an image and goes towards the right edge. The Y axis starts at the top of the image towards image bottom. All image pixels have non-negative coordinates.

void	set_projection_matrix (const mat4 &proj)
	Temporally change the projection matrix.

void	set_modelview_matrix (const mat4 &mv)
	Temporally change the modelview matrix.

void	setPosition (const vec3 &pos) const
	Set the position of the camera.

void	setOrientation (const quat &q) const
	Set the orientation of the camera.

void	setOrientation (float theta, float phi) const
	Set the orientation of the camera.

void	setUpVector (const vec3 &up, bool noMove=true) const
	Set the up vector of the camera.

void	setViewDirection (const vec3 &direction) const
	Set the view direction of the camera.

Positioning tools
void	lookAt (const vec3 &target) const
	Make the camera look at a target.

void	showEntireScene () const
	Show the entire scene.

void	fitSphere (const vec3 &center, float radius) const
	Move the camera so that entire sphere fits the screen.

void	fitBoundingBox (const vec3 &min, const vec3 &max) const
	Move the camera so that entire box fits the screen.

void	fitScreenRegion (int xmin, int ymin, int xmax, int ymax) const
	Moves the Camera so that the rectangular screen region fits the screen.

void	centerScene () const
	Moves the Camera so that its sceneCenter() is projected in the center of the screen.

KeyFrameInterpolator *	keyframe_interpolator () const
	Get the keyframe interpolator.

void	interpolateToLookAt (const vec3 &point)
	Perform keyframe interpolation to look at a point.

void	interpolateToFitScene ()
	Perform keyframe interpolation to fit the scene.

void	interpolateTo (const Frame *frame, float duration)
	Perform keyframe interpolation to a frame.

Type	type () const
	Get the 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.

float	pixelGLRatio (const vec3 &position) const
	Get the pixel GL ratio at a 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.

virtual float	zNear () const
	Get the near clipping plane distance.

virtual float	zFar () const
	Get the far clipping plane distance.

virtual void	getOrthoWidthHeight (float &halfWidth, float &halfHeight) const
	Get the orthographic width and height.

void	getFrustumPlanesCoefficients (float coef[6][4]) const
	Get the frustum planes coefficients.

void	getFrustumPlanesCoefficients2 (float coef[6][4]) const
	Get the frustum planes coefficients (alternative version).

void	setType (Type type)
	Set the type of the camera.

void	setFieldOfView (float fov)
	Set the field of view of the camera.

void	setHorizontalFieldOfView (float hfov)
	Sets the horizontalFieldOfView() of the Camera (in radians).

void	setFOVToFitScene ()
	Set the field of view to fit the scene.

void	setAspectRatio (float aspect)
	Defines the Camera aspectRatio().

void	setScreenWidthAndHeight (int width, int height)
	Set the screen width and height.

void	setZNearCoefficient (float coef)
	Set the zNear coefficient.

void	setZClippingCoefficient (float coef)
	Set the zClipping coefficient.

Scene radius and center
float	sceneRadius () const
	Returns the radius of the scene observed by the Camera.

vec3	sceneCenter () const
	Returns the position of the scene center, defined in the world coordinate system.

float	distanceToSceneCenter () const
	Get the distance to the scene center.

void	setSceneRadius (float radius)
	Set the radius of the scene.

void	setSceneCenter (const vec3 &center)
	Set the center of the scene.

void	setSceneBoundingBox (const vec3 &min, const vec3 &max)
	Set the bounding box of the scene.

void	setPivotPoint (const vec3 &point)
	Set the pivot point of the camera. After this method is called, the Camera rotates around this point.

vec3	pivotPoint () const
	Get the pivot point of the camera.

ManipulatedCameraFrame *	frame () const
	Returns the ManipulatedFrame attached to the Camera.

void	setFrame (ManipulatedCameraFrame *const mcf)
	Set the manipulated frame of the camera.

void	computeProjectionMatrix ()
	Compute the projection matrix.

void	computeModelViewMatrix ()
	Compute the model view matrix.

const mat4 &	projectionMatrix () const
	Get the projection matrix.

const mat4 &	modelViewMatrix () const
	Get the model view matrix.

mat4	modelViewProjectionMatrix () const
	Get the model view projection matrix.

World to Camera coordinate systems conversions
vec3	cameraCoordinatesOf (const vec3 &src) const
	Convert world coordinates to camera coordinates.

vec3	worldCoordinatesOf (const vec3 &src) const
	Convert camera coordinates to world coordinates.

2D screen to 3D world coordinate systems conversions
Signal	frame_modified
	A signal indicating the frame has been modified.

vec3	projectedCoordinatesOf (const vec3 &src, const Frame *frame=nullptr) const
	Returns the screen projected coordinates of a 3D point defined in the frame coordinate system. When `frame` in `NULL` (default), `src` is expressed in the world coordinate system.

vec3	unprojectedCoordinatesOf (const vec3 &src, const Frame *frame=nullptr) const
	Returns the world unprojected coordinates of a point defined in the screen coordinate system. The result is expressed in the `frame` coordinate system. When `frame` is `NULL` (default), the result is expressed in the world coordinate system.

void	convertClickToLine (int x, int y, vec3 &orig, vec3 &dir) const
	Returns the coefficients of a 3D half-line passing through the Camera eye and pixel (x, y).

Detailed Description

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.

Mouse manipulation

The position() and orientation() of the Camera are defined by a ManipulatedFrame (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.

If a pivotPoint() has been set, the Camera observes a scene and rotates around its pivotPoint().

Other functionalities

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 scene radius, scene center, and zClippingCoefficient() by the zNear() and zFar() methods. Reasonable values on the scene extends hence have to be provided to 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. Use playPath() to make the Camera follow the path.

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.

A Camera can also be used outside a viewer 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.

To use the camera, you need to do the following:

Create and (if necessary) setup camera in the constructor of your viewer.
camera_ = new Camera;

camera_->setType(Camera::PERSPECTIVE);

camera_->setUpVector(vec3(0, 0, 1)); // Z pointing up

camera_->setViewDirection(vec3(-1, 0, 0)); // X pointing out

camera_->showEntireScene(); // position and orient the camera

camera_->connect(this, &Viewer::update); // connect the viewer's update function

easy3d::Camera::PERSPECTIVE
@ PERSPECTIVE
Perspective camera.
Definition camera.h:144

easy3d::Camera::Camera
Camera()
Default constructor.

easy3d::Viewer::update
void update() const
Update the display (i.e., repaint).
Definition viewer.cpp:630

easy3d::vec3
Vec< 3, float > vec3
A 3D point/vector of float type.
Definition types.h:44
Call camera_->setScreenWidthAndHeight() at both
- creation or initialization (i.e., before the viewer appears) of the application;
- change of the window size.
Call camera_->frame()->action_start() on mouse down and camera_->frame()->action_end() on mouse up.
Call camera_->frame()->action_rotate() on mouse move for rotation and camera_->frame()->action_translate() on mouse move for translation and camera_->frame()->action_zoom() on mouse move for zoom

To make the entire scene visible, call camera_->setSceneBoundingBox() and camera_->showEntireScene() ;

To retrieve the model view projection matrix, call camera_->modelViewProjectionMatrix()

Examples: Tutorial_207_RealCamera/main.cpp.

Member Enumeration Documentation

◆ Type

enum Type

Enumerates the two possible types of Camera.

See type() and setType(). This type mainly defines different Camera projection matrix (see loadProjectionMatrix()). Many other methods (convertClickToLine(), projectedCoordinatesOf(), pixelGLRatio()...) are affected by this Type.

Enumerator
PERSPECTIVE	Perspective camera.
ORTHOGRAPHIC	Orthographic camera.

Constructor & Destructor Documentation

◆ Camera()

Camera ( const Camera & camera )

Copy constructor.

Parameters

camera The camera to copy.

Member Function Documentation

◆ aspectRatio()

float aspectRatio ( ) const

inline

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

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

Returns: The aspect ratio.

◆ cameraCoordinatesOf()

vec3 cameraCoordinatesOf ( const vec3 & src ) const

Convert world coordinates to camera coordinates.

Parameters

src	The source coordinates in world space.

Returns: The coordinates in camera space.

◆ centerScene()

void centerScene ( ) const

Moves the Camera so that its sceneCenter() is projected in the center of the screen.

This method simply projects the current position on a line passing through sceneCenter(). The orientation() and fieldOfView() are unchanged.

See also: showEntireScene()

◆ convertClickToLine()

void convertClickToLine	(	int	x,
		int	y,
		vec3 &	orig,
		vec3 &	dir ) const

Returns 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 as the origin defined in the upper left corner. Use screenHeight() - y - 1 to convert to OpenGL units.

Parameters

x	The x coordinate of the click.
y	The y coordinate of the click.
orig	The origin of the line.
dir	The direction of the line.

◆ distanceToSceneCenter()

float distanceToSceneCenter ( ) const

Get the distance to the scene center.

Returns: The distance to the scene center.

◆ fieldOfView()

float 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.

Examples: Tutorial_207_RealCamera/main.cpp.

◆ fitBoundingBox()

void fitBoundingBox	(	const vec3 &	min,
		const vec3 &	max ) const

Move the camera so that entire box fits the screen.

Parameters

min	The minimum corner of the bounding box.
max	The maximum corner of the bounding box.

◆ fitScreenRegion()

void fitScreenRegion	(	int	xmin,
		int	ymin,
		int	xmax,
		int	ymax ) const

Moves the Camera so that the rectangular screen region fits the screen.

The rectangular screen region is defined in pixel units, with origin in the upper left corner. 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.

Parameters

xmin	The minimum x coordinate.
ymin	The minimum y coordinate.
xmax	The maximum x coordinate.
ymax	The maximum y coordinate.

◆ fitSphere()

void fitSphere	(	const vec3 &	center,
		float	radius ) const

Move the camera so that entire sphere fits the screen.

Parameters

center	The center of the sphere.
radius	The radius of the sphere.

◆ frame()

ManipulatedCameraFrame * frame ( ) const

inline

Returns the ManipulatedFrame attached to the Camera.

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

Returns: The manipulated frame.

Examples: Tutorial_204_Viewer_Qt/main.cpp, and Tutorial_207_RealCamera/main.cpp.

◆ getFrustumPlanesCoefficients()

void getFrustumPlanesCoefficients ( float coef[6][4] ) const

Get the frustum planes coefficients.

Parameters

coef

The coefficients. 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.

◆ getFrustumPlanesCoefficients2()

void getFrustumPlanesCoefficients2 ( float coef[6][4] ) const

Get the frustum planes coefficients (alternative version).

Parameters

coef

The coefficients. 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.

◆ getOrthoWidthHeight()

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

virtual

Get the orthographic width and height.

Parameters

halfWidth	The half width.
halfHeight	The half height.

◆ horizontalFieldOfView()

float horizontalFieldOfView ( ) const

inline

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

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

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

easy3d::Camera::aspectRatio

float aspectRatio() const

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

Definition camera.h:396

easy3d::Camera::fieldOfView

float fieldOfView() const

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

Definition camera.h:376

easy3d::Camera::horizontalFieldOfView

float horizontalFieldOfView() const

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

Definition camera.h:386

Returns: The horizontal field of view in radians.

◆ interpolateTo()

void interpolateTo	(	const Frame *	frame,
		float	duration )

Perform keyframe interpolation to a frame.

Parameters

frame	The frame to interpolate to.
duration	The duration of the interpolation.

◆ interpolateToLookAt()

void interpolateToLookAt ( const vec3 & point )

Perform keyframe interpolation to look at a point.

Parameters

point The point to look at.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ keyframe_interpolator()

KeyFrameInterpolator * keyframe_interpolator ( ) const

inline

Get the keyframe interpolator.

Returns: The keyframe interpolator.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ lookAt()

void lookAt ( const vec3 & target ) const

Make the camera look at a target.

Parameters

target The target to look at.

◆ modelViewMatrix()

const mat4 & modelViewMatrix ( ) const

Get the model view matrix.

Returns: The model view matrix.

◆ modelViewProjectionMatrix()

mat4 modelViewProjectionMatrix ( ) const

Get the model view projection matrix.

Returns: The model view projection matrix.

◆ operator=()

Camera & operator= ( const Camera & camera )

Assignment operator.

Parameters

camera The camera to assign.

Returns: A reference to this camera.

◆ orientation()

quat orientation ( ) const

Get the orientation of the camera.

Returns: The orientation of the camera.

◆ pivotPoint()

vec3 pivotPoint ( ) const

Get the pivot point of the camera.

Returns: The pivot point.

◆ pixelGLRatio()

float pixelGLRatio ( const vec3 & position ) const

Get the pixel GL ratio at a position.

Parameters

position The position.

Returns: The pixel GL ratio.

◆ position()

vec3 position ( ) const

Get the position of the camera.

Returns: The position of the camera.

◆ projectedCoordinatesOf()

vec3 projectedCoordinatesOf	(	const vec3 &	src,
		const Frame *	frame = nullptr ) const

Returns the screen projected coordinates of a 3D point defined in the frame coordinate system. When frame in NULL (default), src is expressed in the world coordinate system.

Parameters

src	The source coordinates in world space.
frame	The frame to use for the conversion.

Returns: The coordinates in screen space.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ projectionMatrix()

const mat4 & projectionMatrix ( ) const

Get the projection matrix.

Returns: The projection matrix.

◆ rightVector()

vec3 rightVector ( ) const

Get the right vector of the camera.

Returns: The right vector of the camera.

◆ sceneCenter()

vec3 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.

Returns: The center of the scene.

See also: setSceneBoundingBox().

◆ sceneRadius()

float 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.

Returns: The radius of the scene.

See also: setSceneBoundingBox().

Examples: Tutorial_204_Viewer_Qt/main.cpp, and Tutorial_207_RealCamera/main.cpp.

◆ screenHeight()

int screenHeight ( ) const

inline

Returns the height (in pixels) of the Camera screen.

Set using setScreenWidthAndHeight(). This value is automatically fitted to the viewer's window dimensions when the Camera is attached to a Viewer.

Returns: The height in pixels.

◆ screenWidth()

int screenWidth ( ) const

inline

Returns the width (in pixels) of the Camera screen.

Set using setScreenWidthAndHeight(). This value is automatically fitted to the Viewer's window dimensions when the Camera is attached to a viewer.

Returns: The width in pixels.

◆ set_from_calibration() [1/2]

void set_from_calibration ( const mat34 & proj )

Defines the position(), orientation() and fieldOfView() of the camera from calibrated camera intrinsic and extrinsic parameters. This function assumes the camera parameters were obtained by standard camera calibration, in which image coordinates are denoted in pixels, with the origin point (0, 0) corresponding to the top-left corner of the image. The X axis starts at the left edge of an image and goes towards the right edge. The Y axis starts at the top of the image towards image bottom. All image pixels have non-negative coordinates.

Parameters

proj	The projection matrix, which can be computed as P = K * M * [R\|t], where R is a 3x3 matrix representing the camera rotation, and t is a 3D vector describing the camera translation (rotation first then translation).

Attention: The additional M is a 3 by 3 matrix that converts the coordinate system from the vision convention to the OpenGL convention (i.e., inverting Y and Z axes), i.e., M(1, 1) = -1; // invert the Y axis M(2, 2) = -1; // invert the Z axis This is because the camera coordinates in computer vision goes X right, Y down, Z forward, while the camera coordinates in OpenGL goes X right, Y up, Z inward.

See also: set_from_calibration.

◆ set_from_calibration() [2/2]

void set_from_calibration	(	float	fx,
		float	fy,
		float	skew,
		float	cx,
		float	cy,
		const mat3 &	R,
		const vec3 &	t,
		bool	convert = true )

Defines the position(), orientation() and fieldOfView() of the camera from calibrated camera intrinsic and extrinsic parameters. This function assumes the camera parameters were obtained by standard camera calibration, in which image coordinates are denoted in pixels, with the origin point (0, 0) corresponding to the top-left corner of the image. The X axis starts at the left edge of an image and goes towards the right edge. The Y axis starts at the top of the image towards image bottom. All image pixels have non-negative coordinates.

Parameters

fx	The focal length in the x direction.
fy	The focal length in the y direction.
skew	The skew coefficient.
cx	The principal point in the x direction.
cy	The principal point in the y direction.
R	The rotation matrix. It denotes the coordinate system transformation from 3D world coordinates to 3D camera coordinates.
t	The translation vector. It is the position of the origin of the world coordinate system expressed in the camera coordinate system.

Note: t is often mistakenly considered the position of the camera. The position of the camera expressed in world coordinates is C = -inverse(R) * t = -transpose(R) * t.

Parameters

convert True to convert from vision convention to OpenGL convention (i.e., invert Y and Z axes). This is because the camera coordinates of computer vision goes X right, Y down, Z forward, while the camera coordinates of OpenGL goes X right, Y up, Z inward.

See also: set_from_calibration.

Examples: Tutorial_207_RealCamera/main.cpp.

◆ set_from_model_view_matrix()

void set_from_model_view_matrix ( const mat4 & mv ) const

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

This enables a Camera initialisation from another OpenGL application. After this method has been called, getModelViewMatrix() returns a matrix equivalent to mv. Only the orientation() and position() of the Camera are modified.

Parameters

mv	The model view matrix.

◆ set_modelview_matrix()

void set_modelview_matrix ( const mat4 & mv )

Temporally change the modelview matrix.

Parameters

mv	The modelview matrix.

Attention: This function directly changes the modelview matrix. It actually doesn't change any of the camera parameters (i.e., position, orientation, fov, zFar, zNear, etc.). This is only useful if you want to temporally use a different modelview matrix for rendering (e.g., grabbing a snapshot from the framebuffer).

◆ set_projection_matrix()

void set_projection_matrix ( const mat4 & proj )

Temporally change the projection matrix.

Parameters

proj	The projection matrix.

Attention: This function directly changes the projection matrix. It actually doesn't change any of the camera parameters (i.e., position, orientation, fov, zFar, zNear, etc.). This is only useful if you want to temporally use a different projection matrix for rendering (e.g., grabbing a snapshot from the framebuffer).

◆ setAspectRatio()

void setAspectRatio ( float aspect )

inline

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 Viewer. It actually sets the screenHeight() to 100 and the screenWidth() accordingly. See also setFOVToFitScene().

Parameters

aspect The aspect ratio.

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

◆ setFieldOfView()

void setFieldOfView ( float fov )

Set the field of view of the camera.

Parameters

fov	The field of view in radians.

Examples: Tutorial_207_RealCamera/main.cpp.

◆ setFrame()

void setFrame ( ManipulatedCameraFrame *const mcf )

Set the manipulated frame of the camera.

Parameters

mcf	The manipulated frame.

◆ setHorizontalFieldOfView()

void setHorizontalFieldOfView ( float hfov )

inline

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

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

Parameters

hfov	The horizontal field of view in radians.

◆ setOrientation() [1/2]

void setOrientation ( const quat & q ) const

Set the orientation of the camera.

Parameters

q	The orientation of the camera.

Examples: Tutorial_207_RealCamera/main.cpp.

◆ setOrientation() [2/2]

void setOrientation	(	float	theta,
		float	phi ) const

Set the orientation of the camera.

Parameters

theta	The theta angle.
phi	The phi angle.

◆ setPivotPoint()

void setPivotPoint ( const vec3 & point )

Set the pivot point of the camera. After this method is called, the Camera rotates around this point.

Parameters

point The pivot point.

◆ setPosition()

void setPosition ( const vec3 & pos ) const

Set the position of the camera.

Parameters

pos	The position of the camera.

Examples: Tutorial_207_RealCamera/main.cpp.

◆ setSceneBoundingBox()

void setSceneBoundingBox	(	const vec3 &	min,
		const vec3 &	max )

Set the bounding box of the scene.

This method sets the scene center and radius from the bounding box.

Parameters

min	The minimum corner of the bounding box.
max	The maximum corner of the bounding box.

◆ setSceneCenter()

void setSceneCenter ( const vec3 & center )

Set the center of the scene.

Parameters

center The center of the scene.

◆ setSceneRadius()

void setSceneRadius ( float radius )

Set the radius of the scene.

Parameters

radius The radius of the scene.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ setScreenWidthAndHeight()

void setScreenWidthAndHeight	(	int	width,
		int	height )

Set the screen width and height.

Parameters

width	The width in pixels.
height	The height in pixels.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ setType()

void setType ( Type type )

Set the type of the camera.

Parameters

type	The type of the camera.

◆ setUpVector()

void setUpVector	(	const vec3 &	up,
		bool	noMove = true ) const

Set the up vector of the camera.

Parameters

up	The up vector.
noMove	True to not move the camera.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ setViewDirection()

void setViewDirection ( const vec3 & direction ) const

Set the view direction of the camera.

Parameters

direction The view direction.

Examples: Tutorial_204_Viewer_Qt/main.cpp.

◆ setZClippingCoefficient()

void setZClippingCoefficient ( float coef )

inline

Set the zClipping coefficient.

Parameters

coef	The zClipping coefficient.

◆ setZNearCoefficient()

void setZNearCoefficient ( float coef )

inline

Set the zNear coefficient.

Parameters

coef	The zNear coefficient.

◆ type()

Type type ( ) const

inline

Get the type of the camera.

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

Returns: The type of the camera.

◆ unprojectedCoordinatesOf()

vec3 unprojectedCoordinatesOf	(	const vec3 &	src,
		const Frame *	frame = nullptr ) const

Returns the world unprojected coordinates of a point defined in the screen coordinate system. The result is expressed in the frame coordinate system. When frame is NULL (default), the result is expressed in the world coordinate system.

Parameters

src	The source coordinates in screen space.
frame	The frame to use for the conversion.

Returns: The unprojected coordinates.

◆ upVector()

vec3 upVector ( ) const

Get the up vector of the camera.

Returns: The up vector of the camera.

◆ viewDirection()

vec3 viewDirection ( ) const

Get the view direction of the camera.

Returns: The view direction of the camera.

◆ worldCoordinatesOf()

vec3 worldCoordinatesOf ( const vec3 & src ) const

Convert camera coordinates to world coordinates.

Parameters

src	The source coordinates in camera space.

Returns: The coordinates in world space.

◆ zClippingCoefficient()

float 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 guarantees 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. For a total control on clipping planes' positions, another option is to overload the zNear() and zFar() methods.

Attention: When you visualize the Camera paths, set a larger value (suggested value is 5.0) so that the Camera paths are not clipped. Don't forget to restore the previous zClippingCoefficient() value back when you leave this mode.

Returns: The zClipping coefficient.

See also: zNearCoefficient().

◆ zFar()

virtual float zFar ( ) const

virtual

Get the far clipping plane distance.

Returns: The far clipping plane distance.

◆ zNear()

virtual float zNear ( ) const

virtual

Get the near clipping plane distance.

Returns: The near clipping plane distance.

◆ zNearCoefficient()

float 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 0.001, 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 the worst Z precision. Only meaningful when Camera type is Camera::PERSPECTIVE.

Returns: The zNear coefficient.

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

G:/3_code/Easy3D/easy3d/renderer/camera.h

Public Types

Public Member Functions

2D screen to 3D world coordinate systems conversions

Detailed Description

Mouse manipulation

Other functionalities

Member Enumeration Documentation

◆ Type

Constructor & Destructor Documentation

◆ Camera()

Member Function Documentation

◆ aspectRatio()

◆ cameraCoordinatesOf()

◆ centerScene()

◆ convertClickToLine()

◆ distanceToSceneCenter()

◆ fieldOfView()

◆ fitBoundingBox()

◆ fitScreenRegion()

◆ fitSphere()

◆ frame()

◆ getFrustumPlanesCoefficients()

◆ getFrustumPlanesCoefficients2()

◆ getOrthoWidthHeight()

◆ horizontalFieldOfView()

◆ interpolateTo()

◆ interpolateToLookAt()

◆ keyframe_interpolator()

◆ lookAt()

◆ modelViewMatrix()

◆ modelViewProjectionMatrix()

◆ operator=()

◆ orientation()

◆ pivotPoint()

◆ pixelGLRatio()

◆ position()

◆ projectedCoordinatesOf()

◆ projectionMatrix()

◆ rightVector()

◆ sceneCenter()

◆ sceneRadius()

◆ screenHeight()

◆ screenWidth()

◆ set_from_calibration() [1/2]

◆ set_from_calibration() [2/2]

◆ set_from_model_view_matrix()

◆ set_modelview_matrix()

◆ set_projection_matrix()

◆ setAspectRatio()

◆ setFieldOfView()

◆ setFrame()

◆ setHorizontalFieldOfView()

◆ setOrientation() [1/2]

◆ setOrientation() [2/2]

◆ setPivotPoint()

◆ setPosition()

◆ setSceneBoundingBox()

◆ setSceneCenter()

◆ setSceneRadius()

◆ setScreenWidthAndHeight()

◆ setType()

◆ setUpVector()

◆ setViewDirection()

◆ setZClippingCoefficient()

◆ setZNearCoefficient()

◆ type()

◆ unprojectedCoordinatesOf()

◆ upVector()

◆ viewDirection()

◆ worldCoordinatesOf()

◆ zClippingCoefficient()

◆ zFar()

◆ zNear()

◆ zNearCoefficient()