fixed documentation warnings

samples/cpp/tutorial_code/viz/transformations.cpp

@@ -0,0 +1,112 @@
+/**
+ * @file transformations.cpp
+ * @brief Visualizing cloud in different positions, coordinate frames, camera frustums
+ * @author Ozan Cagri Tonkal
+ */
+
+#include <opencv2/viz/vizcore.hpp>
+#include <iostream>
+#include <fstream>
+
+using namespace cv;
+using namespace std;
+
+/**
+ * @function help
+ * @brief Display instructions to use this tutorial program
+ */
+void help()
+{
+    cout
+    << "--------------------------------------------------------------------------"   << endl
+    << "This program shows how to use makeTransformToGlobal() to compute required pose,"
+    << "how to use makeCameraPose and Viz3d::setViewerPose. You can observe the scene "
+    << "from camera point of view (C) or global point of view (G)"                    << endl
+    << "Usage:"                                                                       << endl
+    << "./transformations [ G | C ]"                                                 << endl
+    << endl;
+}
+
+/**
+ * @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)
+{
+    help();
+
+    if (argn < 2)
+    {
+        cout << "Missing arguments." << 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;
+}