Doxygen tutorials: basic structure

doc/tutorials/viz/creating_widgets/creating_widgets.markdown

@@ -0,0 +1,144 @@
+Creating Widgets {#tutorial_creating_widgets}
+================
+
+Goal
+----
+
+In this tutorial you will learn how to
+
+-   Create your own widgets using WidgetAccessor and VTK.
+-   Show your widget in the visualization window.
+
+Code
+----
+
+You can download the code from [here ](samples/cpp/tutorial_code/viz/creating_widgets.cpp).
+@code{.cpp}
+#include <opencv2/viz.hpp>
+#include <opencv2/viz/widget_accessor.hpp>
+#include <iostream>
+
+#include <vtkPoints.h>
+#include <vtkTriangle.h>
+#include <vtkCellArray.h>
+#include <vtkPolyData.h>
+#include <vtkPolyDataMapper.h>
+#include <vtkIdList.h>
+#include <vtkActor.h>
+#include <vtkProp.h>
+
+using namespace cv;
+using namespace std;
+
+/*
+ * @class WTriangle
+ * @brief Defining our own 3D Triangle widget
+ */
+class WTriangle : public viz::Widget3D
+{
+    public:
+        WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color = viz::Color::white());
+};
+
+/*
+ * @function WTriangle::WTriangle
+ */
+WTriangle::WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color)
+{
+    // Create a triangle
+    vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
+    points->InsertNextPoint(pt1.x, pt1.y, pt1.z);
+    points->InsertNextPoint(pt2.x, pt2.y, pt2.z);
+    points->InsertNextPoint(pt3.x, pt3.y, pt3.z);
+
+    vtkSmartPointer<vtkTriangle> triangle = vtkSmartPointer<vtkTriangle>::New();
+    triangle->GetPointIds()->SetId(0,0);
+    triangle->GetPointIds()->SetId(1,1);
+    triangle->GetPointIds()->SetId(2,2);
+
+    vtkSmartPointer<vtkCellArray> cells = vtkSmartPointer<vtkCellArray>::New();
+    cells->InsertNextCell(triangle);
+
+    // Create a polydata object
+    vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
+
+    // Add the geometry and topology to the polydata
+    polyData->SetPoints(points);
+    polyData->SetPolys(cells);
+
+    // Create mapper and actor
+    vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
+#if VTK_MAJOR_VERSION <= 5
+    mapper->SetInput(polyData);
+#else
+    mapper->SetInputData(polyData);
+#endif
+
+    vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
+    actor->SetMapper(mapper);
+
+    // Store this actor in the widget in order that visualizer can access it
+    viz::WidgetAccessor::setProp(*this, actor);
+
+    // Set the color of the widget. This has to be called after WidgetAccessor.
+    setColor(color);
+}
+
+/*
+ * @function main
+ */
+int main()
+{
+    /// Create a window
+    viz::Viz3d myWindow("Creating Widgets");
+
+    /// Create a triangle widget
+    WTriangle tw(Point3f(0.0,0.0,0.0), Point3f(1.0,1.0,1.0), Point3f(0.0,1.0,0.0), viz::Color::red());
+
+    /// Show widget in the visualizer window
+    myWindow.showWidget("TRIANGLE", tw);
+
+    /// Start event loop
+    myWindow.spin();
+
+    return 0;
+}
+@endcode
+Explanation
+-----------
+
+Here is the general structure of the program:
+
+-   Extend Widget3D class to create a new 3D widget.
+@code{.cpp}
+class WTriangle : public viz::Widget3D
+{
+    public:
+        WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color = viz::Color::white());
+};
+@endcode
+-   Assign a VTK actor to the widget.
+@code{.cpp}
+// Store this actor in the widget in order that visualizer can access it
+viz::WidgetAccessor::setProp(*this, actor);
+@endcode
+-   Set color of the widget.
+@code{.cpp}
+// Set the color of the widget. This has to be called after WidgetAccessor.
+setColor(color);
+@endcode
+-   Construct a triangle widget and display it in the window.
+@code{.cpp}
+/// Create a triangle widget
+WTriangle tw(Point3f(0.0,0.0,0.0), Point3f(1.0,1.0,1.0), Point3f(0.0,1.0,0.0), viz::Color::red());
+
+/// Show widget in the visualizer window
+myWindow.showWidget("TRIANGLE", tw);
+@endcode
+Results
+-------
+
+Here is the result of the program.
+
+![image](images/red_triangle.png)
+

doc/tutorials/viz/launching_viz/launching_viz.markdown

@@ -0,0 +1,108 @@
+Launching Viz {#tutorial_launching_viz}
+=============
+
+Goal
+----
+
+In this tutorial you will learn how to
+
+-   Open a visualization window.
+-   Access a window by its name.
+-   Start event loop.
+-   Start event loop for a given amount of time.
+
+Code
+----
+
+You can download the code from [here ](samples/cpp/tutorial_code/viz/launching_viz.cpp).
+@code{.cpp}
+#include <opencv2/viz.hpp>
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+/*
+* @function main
+*/
+int main()
+{
+    /// Create a window
+    viz::Viz3d myWindow("Viz Demo");
+
+    /// Start event loop
+    myWindow.spin();
+
+    /// Event loop is over when pressed q, Q, e, E
+    cout << "First event loop is over" << endl;
+
+    /// Access window via its name
+    viz::Viz3d sameWindow = viz::getWindowByName("Viz Demo");
+
+    /// Start event loop
+    sameWindow.spin();
+
+    /// Event loop is over when pressed q, Q, e, E
+    cout << "Second event loop is over" << endl;
+
+    /// Event loop is over when pressed q, Q, e, E
+    /// Start event loop once for 1 millisecond
+    sameWindow.spinOnce(1, true);
+    while(!sameWindow.wasStopped())
+    {
+        /// Interact with window
+
+        /// Event loop for 1 millisecond
+        sameWindow.spinOnce(1, true);
+    }
+
+    /// Once more event loop is stopped
+    cout << "Last event loop is over" << endl;
+    return 0;
+}
+@endcode
+Explanation
+-----------
+
+Here is the general structure of the program:
+
+-   Create a window.
+@code{.cpp}
+/// Create a window
+viz::Viz3d myWindow("Viz Demo");
+@endcode
+-   Start event loop. This event loop will run until user terminates it by pressing **e**, **E**,
+    **q**, **Q**.
+@code{.cpp}
+/// Start event loop
+myWindow.spin();
+@endcode
+-   Access same window via its name. Since windows are implicitly shared, **sameWindow** is exactly
+    the same with **myWindow**. If the name does not exist, a new window is created.
+@code{.cpp}
+/// Access window via its name
+viz::Viz3d sameWindow = viz::get("Viz Demo");
+@endcode
+-   Start a controlled event loop. Once it starts, **wasStopped** is set to false. Inside the while
+    loop, in each iteration, **spinOnce** is called to prevent event loop from completely stopping.
+    Inside the while loop, user can execute other statements including those which interact with the
+    window.
+@code{.cpp}
+/// Event loop is over when pressed q, Q, e, E
+/// Start event loop once for 1 millisecond
+sameWindow.spinOnce(1, true);
+while(!sameWindow.wasStopped())
+{
+    /// Interact with window
+
+    /// Event loop for 1 millisecond
+    sameWindow.spinOnce(1, true);
+}
+@endcode
+Results
+-------
+
+Here is the result of the program.
+
+![image](images/window_demo.png)
+

doc/tutorials/viz/table_of_content_viz/table_of_content_viz.markdown

@@ -0,0 +1,34 @@
+OpenCV Viz {#tutorial_table_of_content_viz}
+==========
+
+-   @subpage tutorial_launching_viz
+
+    *Compatibility:* \> OpenCV 3.0.0
+
+    *Author:* Ozan Tonkal
+
+    You will learn how to launch a viz window.
+
+-   @subpage tutorial_widget_pose
+
+    *Compatibility:* \> OpenCV 3.0.0
+
+    *Author:* Ozan Tonkal
+
+    You will learn how to change pose of a widget.
+
+-   @subpage tutorial_transformations
+
+    *Compatibility:* \> OpenCV 3.0.0
+
+    *Author:* Ozan Tonkal
+
+    You will learn how to transform between global and camera frames.
+
+-   @subpage tutorial_creating_widgets
+
+    *Compatibility:* \> OpenCV 3.0.0
+
+    *Author:* Ozan Tonkal
+
+    You will learn how to create your own widgets.

doc/tutorials/viz/transformations/transformations.markdown

@@ -0,0 +1,177 @@
+Transformations {#tutorial_transformations}
+===============
+
+Goal
+----
+
+In this tutorial you will learn how to
+
+-   How to use makeTransformToGlobal to compute pose
+-   How to use makeCameraPose and Viz3d::setViewerPose
+-   How to visualize camera position by axes and by viewing frustum
+
+Code
+----
+
+You can download the code from [here ](samples/cpp/tutorial_code/viz/transformations.cpp).
+@code{.cpp}
+#include <opencv2/viz.hpp>
+#include <iostream>
+#include <fstream>
+
+using namespace cv;
+using namespace std;
+
+/*
+ * @function cvcloud_load
+ * @brief load bunny.ply
+ */
+Mat cvcloud_load()
+{
+    Mat cloud(1, 1889, CV_32FC3);
+    ifstream ifs("bunny.ply");
+
+    string str;
+    for(size_t i = 0; i < 12; ++i)
+        getline(ifs, str);
+
+    Point3f* data = cloud.ptr<cv::Point3f>();
+    float dummy1, dummy2;
+    for(size_t i = 0; i < 1889; ++i)
+        ifs >> data[i].x >> data[i].y >> data[i].z >> dummy1 >> dummy2;
+
+    cloud *= 5.0f;
+    return cloud;
+}
+
+/*
+ * @function main
+ */
+int main(int argn, char **argv)
+{
+    if (argn < 2)
+    {
+        cout << "Usage: " << endl << "./transformations [ G | C ]" << endl;
+        return 1;
+    }
+
+    bool camera_pov = (argv[1][0] == 'C');
+
+    /// Create a window
+    viz::Viz3d myWindow("Coordinate Frame");
+
+    /// Add coordinate axes
+    myWindow.showWidget("Coordinate Widget", viz::WCoordinateSystem());
+
+    /// Let's assume camera has the following properties
+    Point3f cam_pos(3.0f,3.0f,3.0f), cam_focal_point(3.0f,3.0f,2.0f), cam_y_dir(-1.0f,0.0f,0.0f);
+
+    /// We can get the pose of the cam using makeCameraPose
+    Affine3f cam_pose = viz::makeCameraPose(cam_pos, cam_focal_point, cam_y_dir);
+
+    /// We can get the transformation matrix from camera coordinate system to global using
+    /// - makeTransformToGlobal. We need the axes of the camera
+    Affine3f transform = viz::makeTransformToGlobal(Vec3f(0.0f,-1.0f,0.0f), Vec3f(-1.0f,0.0f,0.0f), Vec3f(0.0f,0.0f,-1.0f), cam_pos);
+
+    /// Create a cloud widget.
+    Mat bunny_cloud = cvcloud_load();
+    viz::WCloud cloud_widget(bunny_cloud, viz::Color::green());
+
+    /// Pose of the widget in camera frame
+    Affine3f cloud_pose = Affine3f().translate(Vec3f(0.0f,0.0f,3.0f));
+    /// Pose of the widget in global frame
+    Affine3f cloud_pose_global = transform * cloud_pose;
+
+    /// Visualize camera frame
+    if (!camera_pov)
+    {
+        viz::WCameraPosition cpw(0.5); // Coordinate axes
+        viz::WCameraPosition cpw_frustum(Vec2f(0.889484, 0.523599)); // Camera frustum
+        myWindow.showWidget("CPW", cpw, cam_pose);
+        myWindow.showWidget("CPW_FRUSTUM", cpw_frustum, cam_pose);
+    }
+
+    /// Visualize widget
+    myWindow.showWidget("bunny", cloud_widget, cloud_pose_global);
+
+    /// Set the viewer pose to that of camera
+    if (camera_pov)
+        myWindow.setViewerPose(cam_pose);
+
+    /// Start event loop.
+    myWindow.spin();
+
+    return 0;
+}
+@endcode
+Explanation
+-----------
+
+Here is the general structure of the program:
+
+-   Create a visualization window.
+@code{.cpp}
+/// Create a window
+viz::Viz3d myWindow("Transformations");
+@endcode
+-   Get camera pose from camera position, camera focal point and y direction.
+@code{.cpp}
+/// Let's assume camera has the following properties
+Point3f cam_pos(3.0f,3.0f,3.0f), cam_focal_point(3.0f,3.0f,2.0f), cam_y_dir(-1.0f,0.0f,0.0f);
+
+/// We can get the pose of the cam using makeCameraPose
+Affine3f cam_pose = viz::makeCameraPose(cam_pos, cam_focal_point, cam_y_dir);
+@endcode
+-   Obtain transform matrix knowing the axes of camera coordinate system.
+@code{.cpp}
+/// We can get the transformation matrix from camera coordinate system to global using
+/// - makeTransformToGlobal. We need the axes of the camera
+Affine3f transform = viz::makeTransformToGlobal(Vec3f(0.0f,-1.0f,0.0f), Vec3f(-1.0f,0.0f,0.0f), Vec3f(0.0f,0.0f,-1.0f), cam_pos);
+@endcode
+-   Create a cloud widget from bunny.ply file
+@code{.cpp}
+/// Create a cloud widget.
+Mat bunny_cloud = cvcloud_load();
+viz::WCloud cloud_widget(bunny_cloud, viz::Color::green());
+@endcode
+-   Given the pose in camera coordinate system, estimate the global pose.
+@code{.cpp}
+/// Pose of the widget in camera frame
+Affine3f cloud_pose = Affine3f().translate(Vec3f(0.0f,0.0f,3.0f));
+/// Pose of the widget in global frame
+Affine3f cloud_pose_global = transform * cloud_pose;
+@endcode
+-   If the view point is set to be global, visualize camera coordinate frame and viewing frustum.
+@code{.cpp}
+/// Visualize camera frame
+if (!camera_pov)
+{
+    viz::WCameraPosition cpw(0.5); // Coordinate axes
+    viz::WCameraPosition cpw_frustum(Vec2f(0.889484, 0.523599)); // Camera frustum
+    myWindow.showWidget("CPW", cpw, cam_pose);
+    myWindow.showWidget("CPW_FRUSTUM", cpw_frustum, cam_pose);
+}
+@endcode
+-   Visualize the cloud widget with the estimated global pose
+@code{.cpp}
+/// Visualize widget
+myWindow.showWidget("bunny", cloud_widget, cloud_pose_global);
+@endcode
+-   If the view point is set to be camera's, set viewer pose to **cam_pose**.
+@code{.cpp}
+/// Set the viewer pose to that of camera
+if (camera_pov)
+    myWindow.setViewerPose(cam_pose);
+@endcode
+Results
+-------
+
+1.  Here is the result from the camera point of view.
+
+    ![image](images/camera_view_point.png)
+
+2.  Here is the result from global point of view.
+
+    ![image](images/global_view_point.png)
+
+

doc/tutorials/viz/widget_pose/widget_pose.markdown

@@ -0,0 +1,143 @@
+Pose of a widget {#tutorial_widget_pose}
+================
+
+Goal
+----
+
+In this tutorial you will learn how to
+
+-   Add widgets to the visualization window
+-   Use Affine3 to set pose of a widget
+-   Rotating and translating a widget along an axis
+
+Code
+----
+
+You can download the code from [here ](samples/cpp/tutorial_code/viz/widget_pose.cpp).
+@code{.cpp}
+#include <opencv2/viz.hpp>
+#include <opencv2/calib3d.hpp>
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+/*
+ * @function main
+ */
+int main()
+{
+    /// Create a window
+    viz::Viz3d myWindow("Coordinate Frame");
+
+    /// Add coordinate axes
+    myWindow.showWidget("Coordinate Widget", viz::WCoordinateSystem());
+
+    /// Add line to represent (1,1,1) axis
+    viz::WLine axis(Point3f(-1.0f,-1.0f,-1.0f), Point3f(1.0f,1.0f,1.0f));
+    axis.setRenderingProperty(viz::LINE_WIDTH, 4.0);
+    myWindow.showWidget("Line Widget", axis);
+
+    /// Construct a cube widget
+    viz::WCube cube_widget(Point3f(0.5,0.5,0.0), Point3f(0.0,0.0,-0.5), true, viz::Color::blue());
+    cube_widget.setRenderingProperty(viz::LINE_WIDTH, 4.0);
+
+    /// Display widget (update if already displayed)
+    myWindow.showWidget("Cube Widget", cube_widget);
+
+    /// Rodrigues vector
+    Mat rot_vec = Mat::zeros(1,3,CV_32F);
+    float translation_phase = 0.0, translation = 0.0;
+    while(!myWindow.wasStopped())
+    {
+        /* Rotation using rodrigues */
+        /// Rotate around (1,1,1)
+        rot_vec.at<float>(0,0) += CV_PI * 0.01f;
+        rot_vec.at<float>(0,1) += CV_PI * 0.01f;
+        rot_vec.at<float>(0,2) += CV_PI * 0.01f;
+
+        /// Shift on (1,1,1)
+        translation_phase += CV_PI * 0.01f;
+        translation = sin(translation_phase);
+
+        Mat rot_mat;
+        Rodrigues(rot_vec, rot_mat);
+
+        /// Construct pose
+        Affine3f pose(rot_mat, Vec3f(translation, translation, translation));
+
+        myWindow.setWidgetPose("Cube Widget", pose);
+
+        myWindow.spinOnce(1, true);
+    }
+
+    return 0;
+}
+@endcode
+Explanation
+-----------
+
+Here is the general structure of the program:
+
+-   Create a visualization window.
+@code{.cpp}
+/// Create a window
+viz::Viz3d myWindow("Coordinate Frame");
+@endcode
+-   Show coordinate axes in the window using CoordinateSystemWidget.
+@code{.cpp}
+/// Add coordinate axes
+myWindow.showWidget("Coordinate Widget", viz::WCoordinateSystem());
+@endcode
+-   Display a line representing the axis (1,1,1).
+@code{.cpp}
+/// Add line to represent (1,1,1) axis
+viz::WLine axis(Point3f(-1.0f,-1.0f,-1.0f), Point3f(1.0f,1.0f,1.0f));
+axis.setRenderingProperty(viz::LINE_WIDTH, 4.0);
+myWindow.showWidget("Line Widget", axis);
+@endcode
+-   Construct a cube.
+@code{.cpp}
+/// Construct a cube widget
+viz::WCube cube_widget(Point3f(0.5,0.5,0.0), Point3f(0.0,0.0,-0.5), true, viz::Color::blue());
+cube_widget.setRenderingProperty(viz::LINE_WIDTH, 4.0);
+myWindow.showWidget("Cube Widget", cube_widget);
+@endcode
+-   Create rotation matrix from rodrigues vector
+@code{.cpp}
+/// Rotate around (1,1,1)
+rot_vec.at<float>(0,0) += CV_PI * 0.01f;
+rot_vec.at<float>(0,1) += CV_PI * 0.01f;
+rot_vec.at<float>(0,2) += CV_PI * 0.01f;
+
+...
+
+Mat rot_mat;
+Rodrigues(rot_vec, rot_mat);
+@endcode
+-   Use Affine3f to set pose of the cube.
+@code{.cpp}
+/// Construct pose
+Affine3f pose(rot_mat, Vec3f(translation, translation, translation));
+myWindow.setWidgetPose("Cube Widget", pose);
+@endcode
+-   Animate the rotation using wasStopped and spinOnce
+@code{.cpp}
+while(!myWindow.wasStopped())
+{
+    ...
+
+    myWindow.spinOnce(1, true);
+}
+@endcode
+Results
+-------
+
+Here is the result of the program.
+
+\htmlonly
+<div align="center">
+<iframe width="420" height="315" src="https://www.youtube.com/embed/22HKMN657U0" frameborder="0" allowfullscreen></iframe>
+</div>
+\endhtmlonly
+