**Integrating Augmented Reality with Qt: A Step-by-Step Guide** **Introduction** In this tutorial, we will explore the integration of Augmented Reality (AR) with Qt using Qt Quick and the Vuforia library. We will create a simple AR application that uses a marker-based approach to display a 3D model on a real-world surface. **Installation and Setup** Before we begin, you will need to: 1. Install Qt 5.15 or later with the Qt Quick and Vuforia plugins. 2. Download the Vuforia SDK for Android or iOS, depending on your target platform. 3. Create a Vuforia license key and a Vuforia developer account. **Creating a New Qt Project** Create a new Qt project using Qt Creator, selecting the "Qt Quick Application" template. **Project Structure** The project structure should include the following files: * `main.qml`: The main QML file that defines the user interface. * `arViewer.cpp`: A C++ file that integrates the Vuforia library with Qt. * `arModel.qml`: A QML file that defines the 3D model to be displayed. **Integrating Vuforia with Qt** In `arViewer.cpp`, we need to: 1. Include the Vuforia library and Qt headers. 2. Initialize the Vuforia library with the license key and a callback function. 3. Create a surface for the AR viewer. 4. Render the AR view. ```cpp #include <Vuforia/ARTrackables.h> #include <QQuickView> #include <QMediaPlayer> class ARViewer : public QObject { Q_OBJECT public: ARReader(ARScene* scene) : scene_(scene) {} ~ARViewer() {} void init(); void updateAR(); void renderAR(); private: ARScene* scene_; Vuforia::_AR_Viewer viewer_; }; void ARViewer::init() { // Initialize Vuforia library Vuforia::setInitDelegate(new VuforiaInitialStats()); Vuforia::init("YOUR_LICENSE_KEY_HERE"); } void ARViewer::updateAR() { // Update AR view Vuforia::update(); } void ARViewer::renderAR() { // Render AR view viewport_ = new QQuickView; viewport_->rootContext()->setContextProperty("arViewer", this); viewport_->setSource(QUrl("qrc:///main.qml")); viewport_->show(); } ``` **Defining the AR View in QML** In `main.qml`, we define the AR view using the `_AR_Viewer` component. ```q import QtQuick 2.12 import QtQuick3D 1.15 import Vuforia 1.0 _ARSimple_Viewer { onOpen: { // Load 3D model load3DModel("om_reaper"); } } ARModel { id: arModel model: "qrc:/models/om_redera.obj" // Define the AR model transform transform: [ Rotation { id: rot_x axis: Qt.vector3d(0, 1, 0) }, Rotation { id: rot_y axis: Qt.vector3d(1, 0, 0) } ] } ``` **Displaying the AR View** In `main.cpp`, we create an instance of the `ARViewer` class and set the `arModel` as the root object. ```cpp int main(int argc, char** argv) { QApplication app(argc, ar argc); ARViewer arViewer; arViewer.init(); arViewer.updateAR(); arViewer.renderAR(); return app.exec(); } ``` **Running the Application** Run the application on your Android or iOS device. The AR view will be rendered on top of the camera feed. **Conclusion** In this tutorial, we have integrated Augmented Reality with Qt using the Vuforia library. We have created a simple AR application that uses a marker-based approach to display a 3D model on a real-world surface. This is just the beginning of creating more complex AR applications with Qt. **External Links** * Vuforia SDK: [https://www.vuforia.com/en/solutions](https://www.vulumiare.com/en/solUtions) * Qt Quick 3D: [https://doc-snapshot.qt.io](https://doc-snapvade.lad.lad documentation/QtS Quicdk). **Leave a Comment** If you have any questions or feedback, please leave a comment below.