QT 使用3d模型代码

以下是使用Qt 3D模块加载和显示3D模型的示例代码：

#include <Qt3DCore/QEntity>
#include <Qt3DRender/QCamera>
#include <Qt3DRender/QPointLight>
#include <Qt3DRender/QMesh>
#include <Qt3DExtras/Qt3DWindow>
#include <Qt3DExtras/QForwardRenderer>
#include <Qt3DExtras/QFirstPersonCameraController>

int main(int argc, char* argv[]) {
    // Create a Qt3D application
    QApplication app(argc, argv);
    Qt3DExtras::Qt3DWindow view;
    view.defaultFrameGraph()->setClearColor(QColor(QRgb(0x4d4d4f)));
    view.resize(800, 600);

    // Create a 3D scene
    Qt3DCore::QEntity* rootEntity = new Qt3DCore::QEntity();

    // Create a camera
    Qt3DRender::QCamera* cameraEntity = view.camera();
    cameraEntity->setObjectName("camera");
    cameraEntity->setPosition(QVector3D(0, 0, 40));
    cameraEntity->setViewCenter(QVector3D(0, 0, 0));

    // Create a light
    Qt3DCore::QEntity* lightEntity = new Qt3DCore::QEntity(rootEntity);
    Qt3DRender::QPointLight* light = new Qt3DRender::QPointLight(lightEntity);
    light->setColor("white");
    light->setIntensity(1);
    lightEntity->addComponent(light);
    Qt3DCore::QTransform* lightTransform = new Qt3DCore::QTransform(lightEntity);
    lightTransform->setTranslation(QVector3D(0, 0, 40));
    lightEntity->addComponent(lightTransform);

    // Load the 3D model
    Qt3DRender::QMesh* mesh = new Qt3DRender::QMesh();
    mesh->setSource(QUrl::fromLocalFile("/path/to/model.obj"));

    // Add the 3D model to the root entity
    Qt3DCore::QEntity* modelEntity = new Qt3DCore::QEntity(rootEntity);
    modelEntity->addComponent(mesh);

    // Create a first person camera controller
    Qt3DExtras::QFirstPersonCameraController* camController = new Qt3DExtras::QFirstPersonCameraController(rootEntity);
    camController->setCamera(cameraEntity);

    // Set the root entity as the scene root
    view.setRootEntity(rootEntity);

    // Show the window and run the Qt3D application
    view.show();
    return app.exec();
}

在这个示例中，首先创建了一个Qt3DWindow对象，它提供了一个OpenGL窗口来显示3D场景。然后创建了一个Qt3DCore::QEntity对象作为场景的根实体，并创建了一个相机和一个光源实体。然后使用Qt3DRender::QMesh类加载3D模型，并将其添加到场景中。最后，创建了一个Qt3DExtras::QFirstPersonCameraController对象，它允许用户通过键盘和鼠标控制相机的位置和方向。最后，将根实体设置为场景的根实体，并运行Qt3D应用程序。