doc/tutorials/viz/widget_pose/widget_pose.markdown

   1 Pose of a widget {#tutorial_widget_pose}
   2 ================
   3
   4 @prev_tutorial{tutorial_launching_viz}
   5 @next_tutorial{tutorial_transformations}
   6
   7 Goal
   8 ----
   9
  10 In this tutorial you will learn how to
  11
  12 -   Add widgets to the visualization window
  13 -   Use Affine3 to set pose of a widget
  14 -   Rotating and translating a widget along an axis
  15
  16 Code
  17 ----
  18
  19 You can download the code from [here ](https://github.com/opencv/opencv/tree/3.4/samples/cpp/tutorial_code/viz/widget_pose.cpp).
  20 @include samples/cpp/tutorial_code/viz/widget_pose.cpp
  21
  22 Explanation
  23 -----------
  24
  25 Here is the general structure of the program:
  26
  27 -   Create a visualization window.
  28     @code{.cpp}
  29     /// Create a window
  30     viz::Viz3d myWindow("Coordinate Frame");
  31     @endcode
  32 -   Show coordinate axes in the window using CoordinateSystemWidget.
  33     @code{.cpp}
  34     /// Add coordinate axes
  35     myWindow.showWidget("Coordinate Widget", viz::WCoordinateSystem());
  36     @endcode
  37 -   Display a line representing the axis (1,1,1).
  38     @code{.cpp}
  39     /// Add line to represent (1,1,1) axis
  40     viz::WLine axis(Point3f(-1.0f,-1.0f,-1.0f), Point3f(1.0f,1.0f,1.0f));
  41     axis.setRenderingProperty(viz::LINE_WIDTH, 4.0);
  42     myWindow.showWidget("Line Widget", axis);
  43     @endcode
  44 -   Construct a cube.
  45     @code{.cpp}
  46     /// Construct a cube widget
  47     viz::WCube cube_widget(Point3f(0.5,0.5,0.0), Point3f(0.0,0.0,-0.5), true, viz::Color::blue());
  48     cube_widget.setRenderingProperty(viz::LINE_WIDTH, 4.0);
  49     myWindow.showWidget("Cube Widget", cube_widget);
  50     @endcode
  51 -   Create rotation matrix from rodrigues vector
  52     @code{.cpp}
  53     /// Rotate around (1,1,1)
  54     rot_vec.at<float>(0,0) += CV_PI * 0.01f;
  55     rot_vec.at<float>(0,1) += CV_PI * 0.01f;
  56     rot_vec.at<float>(0,2) += CV_PI * 0.01f;
  57
  58     ...
  59
  60     Mat rot_mat;
  61     Rodrigues(rot_vec, rot_mat);
  62     @endcode
  63 -   Use Affine3f to set pose of the cube.
  64     @code{.cpp}
  65     /// Construct pose
  66     Affine3f pose(rot_mat, Vec3f(translation, translation, translation));
  67     myWindow.setWidgetPose("Cube Widget", pose);
  68     @endcode
  69 -   Animate the rotation using wasStopped and spinOnce
  70     @code{.cpp}
  71     while(!myWindow.wasStopped())
  72     {
  73         ...
  74
  75         myWindow.spinOnce(1, true);
  76     }
  77     @endcode
  78
  79 Results
  80 -------
  81
  82 Here is the result of the program.
  83
  84 \htmlonly
  85 <div align="center">
  86 <iframe width="420" height="315" src="https://www.youtube.com/embed/22HKMN657U0" frameborder="0" allowfullscreen></iframe>
  87 </div>
  88 \endhtmlonly