.. _widget_pose: Pose of a widget **************** Goal ==== In this tutorial you will learn how to .. container:: enumeratevisibleitemswithsquare * 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 :download:`here <../../../../samples/cpp/tutorial_code/viz/widget_pose.cpp>`. .. code-block:: cpp #include #include #include 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(0,0) += CV_PI * 0.01f; rot_vec.at(0,1) += CV_PI * 0.01f; rot_vec.at(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; } Explanation =========== Here is the general structure of the program: * Create a visualization window. .. code-block:: cpp /// Create a window viz::Viz3d myWindow("Coordinate Frame"); * Show coordinate axes in the window using CoordinateSystemWidget. .. code-block:: cpp /// Add coordinate axes myWindow.showWidget("Coordinate Widget", viz::WCoordinateSystem()); * Display a line representing the axis (1,1,1). .. code-block:: 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); * Construct a cube. .. code-block:: 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); * Create rotation matrix from rodrigues vector .. code-block:: cpp /// Rotate around (1,1,1) rot_vec.at(0,0) += CV_PI * 0.01f; rot_vec.at(0,1) += CV_PI * 0.01f; rot_vec.at(0,2) += CV_PI * 0.01f; ... Mat rot_mat; Rodrigues(rot_vec, rot_mat); * Use Affine3f to set pose of the cube. .. code-block:: cpp /// Construct pose Affine3f pose(rot_mat, Vec3f(translation, translation, translation)); myWindow.setWidgetPose("Cube Widget", pose); * Animate the rotation using wasStopped and spinOnce .. code-block:: cpp while(!myWindow.wasStopped()) { ... myWindow.spinOnce(1, true); } Results ======= Here is the result of the program. .. raw:: html