/** * @file transformations.cpp * @brief Visualizing cloud in different positions, coordinate frames, camera frustums * @author Ozan Cagri Tonkal */ #include <opencv2/viz.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; }