OpenCV/opencv_contrib/modules/viz/tutorials/creating_widgets/creating_widgets.markdown

Creating Widgets {#tutorial_creating_widgets}

@prev_tutorial{tutorial_transformations} @next_tutorial{tutorial_histo3D}

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 . @include viz/samples/creating_widgets.cpp

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.