Viz¶

This section describes 3D visualization window as well as classes and methods that are used to interact with it.

3D visualization window (see Viz3d) is used to display widgets (see Widget), and it provides several methods to interact with scene and widgets.

viz::makeTransformToGlobal¶

Takes coordinate frame data and builds transform to global coordinate frame.

C++: Affine3d viz::makeTransformToGlobal(const Vec3f& axis_x, const Vec3f& axis_y, const Vec3f& axis_z, const Vec3f& origin=Vec3f::all(0))¶

Parameters:	axis_x – X axis vector in global coordinate frame. axis_y – Y axis vector in global coordinate frame. axis_z – Z axis vector in global coordinate frame. origin – Origin of the coordinate frame in global coordinate frame.

This function returns affine transform that describes transformation between global coordinate frame and a given coordinate frame.

viz::makeCameraPose¶

Constructs camera pose from position, focal_point and up_vector (see gluLookAt() for more infromation).

C++: Affine3d makeCameraPose(const Vec3f& position, const Vec3f& focal_point, const Vec3f& y_dir)¶

Parameters:	position – Position of the camera in global coordinate frame. focal_point – Focal point of the camera in global coordinate frame. y_dir – Up vector of the camera in global coordinate frame.

This function returns pose of the camera in global coordinate frame.

viz::getWindowByName¶

Retrieves a window by its name.

C++: Viz3d getWindowByName(const String& window_name)¶

Parameters:	window_name – Name of the window that is to be retrieved.

This function returns a Viz3d object with the given name.

Note

If the window with that name already exists, that window is returned. Otherwise, new window is created with the given name, and it is returned.

Note

Window names are automatically prefixed by “Viz - ” if it is not done by the user.

/// window and window_2 are the same windows.
viz::Viz3d window   = viz::getWindowByName("myWindow");
viz::Viz3d window_2 = viz::getWindowByName("Viz - myWindow");

viz::isNan¶

Checks float/double value for nan.

C++: bool isNan(float x)¶

C++: bool isNan(double x)¶

Parameters:

x – return true if nan.

Checks vector for nan.

C++: bool isNan(const Vec<_Tp, cn>& v)¶

Parameters:

v – return true if any of the elements of the vector is nan.

Checks point for nan

C++: bool isNan(const Point3_<_Tp>& p)¶

Parameters:

p – return true if any of the elements of the point is nan.

viz::Viz3d¶

class Viz3d¶

The Viz3d class represents a 3D visualizer window. This class is implicitly shared.

class CV_EXPORTS Viz3d
{
public:
    typedef cv::Ptr<Viz3d> Ptr;
    typedef void (*KeyboardCallback)(const KeyboardEvent&, void*);
    typedef void (*MouseCallback)(const MouseEvent&, void*);

    Viz3d(const String& window_name = String());
    Viz3d(const Viz3d&);
    Viz3d& operator=(const Viz3d&);
    ~Viz3d();

    void showWidget(const String &id, const Widget &widget, const Affine3d &pose = Affine3d::Identity());
    void removeWidget(const String &id);
    Widget getWidget(const String &id) const;
    void removeAllWidgets();

    void setWidgetPose(const String &id, const Affine3d &pose);
    void updateWidgetPose(const String &id, const Affine3d &pose);
    Affine3d getWidgetPose(const String &id) const;

    void showImage(InputArray image, const Size& window_size = Size(-1, -1));

    void setCamera(const Camera &camera);
    Camera getCamera() const;
    Affine3d getViewerPose();
    void setViewerPose(const Affine3d &pose);

    void resetCameraViewpoint (const String &id);
    void resetCamera();

    void convertToWindowCoordinates(const Point3d &pt, Point3d &window_coord);
    void converTo3DRay(const Point3d &window_coord, Point3d &origin, Vec3d &direction);

    Size getWindowSize() const;
    void setWindowSize(const Size &window_size);
    String getWindowName() const;
    void saveScreenshot (const String &file);
    void setWindowPosition (int x, int y);
    void setFullScreen (bool mode);
    void setBackgroundColor(const Color& color = Color::black());

    void spin();
    void spinOnce(int time = 1, bool force_redraw = false);
    bool wasStopped() const;

    void registerKeyboardCallback(KeyboardCallback callback, void* cookie = 0);
    void registerMouseCallback(MouseCallback callback, void* cookie = 0);

    void setRenderingProperty(const String &id, int property, double value);
    double getRenderingProperty(const String &id, int property);


    void setRepresentation(int representation);
private:
    /* hidden */
};

viz::Viz3d::Viz3d¶

The constructors.

C++: Viz3d::Viz3d(const String& window_name=String())¶

Parameters:	window_name – Name of the window.

viz::Viz3d::showWidget¶

Shows a widget in the window.

C++: void Viz3d::showWidget(const String& id, const Widget& widget, const Affine3d& pose=Affine3d::Identity())¶

Parameters:	id – A unique id for the widget. widget – The widget to be displayed in the window. pose – Pose of the widget.

viz::Viz3d::removeWidget¶

Removes a widget from the window.

C++: void removeWidget(const String& id)¶

Parameters:	id – The id of the widget that will be removed.

viz::Viz3d::getWidget¶

Retrieves a widget from the window. A widget is implicitly shared; that is, if the returned widget is modified, the changes will be immediately visible in the window.

C++: Widget getWidget(const String& id) const¶

Parameters:	id – The id of the widget that will be returned.

viz::Viz3d::removeAllWidgets¶

Removes all widgets from the window.

C++: void removeAllWidgets()¶

viz::Viz3d::showImage¶

Removed all widgets and displays image scaled to whole window area.

C++: void showImage(InputArray image, const Size& window_size=Size(-1, -1))¶

Parameters:	image – Image to be displayed. size – Size of Viz3d window. Default value means no change.

viz::Viz3d::setWidgetPose¶

Sets pose of a widget in the window.

C++: void setWidgetPose(const String& id, const Affine3d& pose)¶

Parameters:	id – The id of the widget whose pose will be set. pose – The new pose of the widget.

viz::Viz3d::updateWidgetPose¶

Updates pose of a widget in the window by pre-multiplying its current pose.

C++: void updateWidgetPose(const String& id, const Affine3d& pose)¶

Parameters:	id – The id of the widget whose pose will be updated. pose – The pose that the current pose of the widget will be pre-multiplied by.

viz::Viz3d::getWidgetPose¶

Returns the current pose of a widget in the window.

C++: Affine3d getWidgetPose(const String& id) const¶

Parameters:	id – The id of the widget whose pose will be returned.

viz::Viz3d::setCamera¶

Sets the intrinsic parameters of the viewer using Camera.

C++: void setCamera(const Camera& camera)¶

Parameters:	camera – Camera object wrapping intrinsinc parameters.

viz::Viz3d::getCamera¶

Returns a camera object that contains intrinsic parameters of the current viewer.

C++: Camera getCamera() const¶

viz::Viz3d::getViewerPose¶

Returns the current pose of the viewer.

..ocv:function:: Affine3d getViewerPose()

viz::Viz3d::setViewerPose¶

Sets pose of the viewer.

C++: void setViewerPose(const Affine3d& pose)¶

Parameters:	pose – The new pose of the viewer.

viz::Viz3d::resetCameraViewpoint¶

Resets camera viewpoint to a 3D widget in the scene.

C++: void resetCameraViewpoint(const String& id)¶

Parameters:	pose – Id of a 3D widget.

viz::Viz3d::resetCamera¶

Resets camera.

C++: void resetCamera()¶

viz::Viz3d::convertToWindowCoordinates¶

Transforms a point in world coordinate system to window coordinate system.

C++: void convertToWindowCoordinates(const Point3d& pt, Point3d& window_coord)¶

Parameters:	pt – Point in world coordinate system. window_coord – Output point in window coordinate system.

viz::Viz3d::converTo3DRay¶

Transforms a point in window coordinate system to a 3D ray in world coordinate system.

C++: void converTo3DRay(const Point3d& window_coord, Point3d& origin, Vec3d& direction)¶

Parameters:	window_coord – Point in window coordinate system. origin – Output origin of the ray. direction – Output direction of the ray.

viz::Viz3d::getWindowSize¶

Returns the current size of the window.

C++: Size getWindowSize() const¶

viz::Viz3d::setWindowSize¶

Sets the size of the window.

C++: void setWindowSize(const Size& window_size)¶

Parameters:	window_size – New size of the window.

viz::Viz3d::getWindowName¶

Returns the name of the window which has been set in the constructor.

C++: String getWindowName() const¶

viz::Viz3d::saveScreenshot¶

Saves screenshot of the current scene.

C++: void saveScreenshot(const String& file)¶

Parameters:	file – Name of the file.

viz::Viz3d::setWindowPosition¶

Sets the position of the window in the screen.

C++: void setWindowPosition(int x, int y)¶

Parameters:	x – x coordinate of the window y – y coordinate of the window

viz::Viz3d::setFullScreen¶

Sets or unsets full-screen rendering mode.

C++: void setFullScreen(bool mode)¶

Parameters:	mode – If true, window will use full-screen mode.

viz::Viz3d::setBackgroundColor¶

Sets background color.

C++: void setBackgroundColor(const Color& color=Color::black())¶

viz::Viz3d::spin¶

The window renders and starts the event loop.

C++: void spin()¶

viz::Viz3d::spinOnce¶

Starts the event loop for a given time.

C++: void spinOnce(int time=1, bool force_redraw=false)¶

Parameters:	time – Amount of time in milliseconds for the event loop to keep running. force_draw – If true, window renders.

viz::Viz3d::wasStopped¶

Returns whether the event loop has been stopped.

C++: bool wasStopped()¶

viz::Viz3d::registerKeyboardCallback¶

Sets keyboard handler.

C++: void registerKeyboardCallback(KeyboardCallback callback, void* cookie=0)¶

Parameters:	callback – Keyboard callback `(void (KeyboardCallbackFunction(const KeyboardEvent&, void))`. cookie – The optional parameter passed to the callback.

viz::Viz3d::registerMouseCallback¶

Sets mouse handler.

C++: void registerMouseCallback(MouseCallback callback, void* cookie=0)¶

Parameters:	callback – Mouse callback `(void (MouseCallback)(const MouseEvent&, void))`. cookie – The optional parameter passed to the callback.

viz::Viz3d::setRenderingProperty¶

Sets rendering property of a widget.

C++: void setRenderingProperty(const String& id, int property, double value)¶

Parameters:	id – Id of the widget. property – Property that will be modified. value – The new value of the property.

Rendering property can be one of the following:

POINT_SIZE
OPACITY
LINE_WIDTH
FONT_SIZE
REPRESENTATION: Expected values are
- REPRESENTATION_POINTS
- REPRESENTATION_WIREFRAME
- REPRESENTATION_SURFACE
IMMEDIATE_RENDERING:
- Turn on immediate rendering by setting the value to 1.
- Turn off immediate rendering by setting the value to 0.
SHADING: Expected values are
- SHADING_FLAT
- SHADING_GOURAUD
- SHADING_PHONG

viz::Viz3d::getRenderingProperty¶

Returns rendering property of a widget.

C++: double getRenderingProperty(const String& id, int property)¶

Parameters:	id – Id of the widget. property – Property.

Rendering property can be one of the following:

POINT_SIZE
OPACITY
LINE_WIDTH
FONT_SIZE
REPRESENTATION: Expected values are
- REPRESENTATION_POINTS
- REPRESENTATION_WIREFRAME
- REPRESENTATION_SURFACE
IMMEDIATE_RENDERING:
- Turn on immediate rendering by setting the value to 1.
- Turn off immediate rendering by setting the value to 0.
SHADING: Expected values are
- SHADING_FLAT
- SHADING_GOURAUD
- SHADING_PHONG

viz::Viz3d::setRepresentation¶

Sets geometry representation of the widgets to surface, wireframe or points.

C++: void setRepresentation(int representation)¶

Parameters:	representation – Geometry representation which can be one of the following: REPRESENTATION_POINTS REPRESENTATION_WIREFRAME REPRESENTATION_SURFACE

viz::Color¶

class Color¶

This class a represents BGR color.

class CV_EXPORTS Color : public Scalar
{
public:
    Color();
    Color(double gray);
    Color(double blue, double green, double red);

    Color(const Scalar& color);

    static Color black();
    static Color blue();
    static Color green();
    static Color cyan();

    static Color red();
    static Color magenta();
    static Color yellow();
    static Color white();

    static Color gray();
};

viz::Mesh¶

class Mesh¶

This class wraps mesh attributes, and it can load a mesh from a ply file.

class CV_EXPORTS Mesh
{
public:

    Mat cloud, colors, normals;

    //! Raw integer list of the form: (n,id1,id2,...,idn, n,id1,id2,...,idn, ...)
    //! where n is the number of points in the poligon, and id is a zero-offset index into an associated cloud.
    Mat polygons;

    //! Loads mesh from a given ply file
    static Mesh load(const String& file);
};

viz::Mesh::load¶

Loads a mesh from a ply file.

C++: static Mesh load(const String& file)¶

Parameters:	file – File name (for no only PLY is supported)

viz::KeyboardEvent¶

class KeyboardEvent¶

This class represents a keyboard event.

class CV_EXPORTS KeyboardEvent
{
public:
    enum { ALT = 1, CTRL = 2, SHIFT = 4 };
    enum Action { KEY_UP = 0, KEY_DOWN = 1 };

    KeyboardEvent(Action action, const String& symbol, unsigned char code, int modifiers);

    Action action;
    String symbol;
    unsigned char code;
    int modifiers;
};

viz::KeyboardEvent::KeyboardEvent¶

Constructs a KeyboardEvent.

C++: KeyboardEvent(Action action, const String& symbol, unsigned char code, Modifiers modifiers)¶

Parameters:	action – Signals if key is pressed or released. symbol – Name of the key. code – Code of the key. modifiers – Signals if `alt`, `ctrl` or `shift` are pressed or their combination.

viz::MouseEvent¶

class MouseEvent¶

This class represents a mouse event.

class CV_EXPORTS MouseEvent
{
public:
    enum Type { MouseMove = 1, MouseButtonPress, MouseButtonRelease, MouseScrollDown, MouseScrollUp, MouseDblClick } ;
    enum MouseButton { NoButton = 0, LeftButton, MiddleButton, RightButton, VScroll } ;

    MouseEvent(const Type& type, const MouseButton& button, const Point& pointer, int modifiers);

    Type type;
    MouseButton button;
    Point pointer;
    int modifiers;
};

viz::MouseEvent::MouseEvent¶

Constructs a MouseEvent.

C++: MouseEvent(const Type& type, const MouseButton& button, const Point& p, Modifiers modifiers)¶

Parameters:

type – Type of the event. This can be MouseMove, MouseButtonPress, MouseButtonRelease, MouseScrollDown, MouseScrollUp, MouseDblClick.
button – Mouse button. This can be NoButton, LeftButton, MiddleButton, RightButton, VScroll.
p – Position of the event.
modifiers – Signals if alt, ctrl or shift are pressed or their combination.

viz::Camera¶

class Camera¶

This class wraps intrinsic parameters of a camera. It provides several constructors that can extract the intrinsic parameters from field of view, intrinsic matrix and projection matrix.

class CV_EXPORTS Camera
{
public:
    Camera(double f_x, double f_y, double c_x, double c_y, const Size &window_size);
    Camera(const Vec2d &fov, const Size &window_size);
    Camera(const Matx33d &K, const Size &window_size);
    Camera(const Matx44d &proj, const Size &window_size);

    inline const Vec2d & getClip() const;
    inline void setClip(const Vec2d &clip);

    inline const Size & getWindowSize() const;
    void setWindowSize(const Size &window_size);

    inline const Vec2d & getFov() const;
    inline void setFov(const Vec2d & fov);

    inline const Vec2d & getPrincipalPoint() const;
    inline const Vec2d & getFocalLength() const;

    void computeProjectionMatrix(Matx44d &proj) const;

    static Camera KinectCamera(const Size &window_size);

private:
    /* hidden */
};

viz::Camera::Camera¶

Constructs a Camera.

C++: Camera(double f_x, double f_y, double c_x, double c_y, const Size& window_size)¶

Parameters:	f_x – Horizontal focal length. f_y – Vertical focal length. c_x – x coordinate of the principal point. c_y – y coordinate of the principal point. window_size – Size of the window. This together with focal length and principal point determines the field of view.

C++: Camera(const Vec2d& fov, const Size& window_size)¶

Parameters:	fov – Field of view (horizontal, vertical) window_size – Size of the window.

Principal point is at the center of the window by default.

C++: Camera(const Matx33d& K, const Size& window_size)¶

Parameters:	K – Intrinsic matrix of the camera. window_size – Size of the window. This together with intrinsic matrix determines the field of view.

C++: Camera(const Matx44d& proj, const Size& window_size)¶

Parameters:	proj – Projection matrix of the camera. window_size – Size of the window. This together with projection matrix determines the field of view.

viz::Camera::computeProjectionMatrix¶

Computes projection matrix using intrinsic parameters of the camera.

C++: void computeProjectionMatrix(Matx44d& proj) const¶

Parameters:	proj – Output projection matrix.

viz::Camera::KinectCamera¶

Creates a Kinect Camera.

C++: static Camera KinectCamera(const Size& window_size)¶

Parameters:	window_size – Size of the window. This together with intrinsic matrix of a Kinect Camera determines the field of view.

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