Qt3D在场景上删除和添加对象

Question

我想每33毫秒在屏幕上绘制一个新的点云。我可以画点云1次。然后，我无法从屏幕上删除所有绘制的点，只能删除一半的位置。

在这里，我描述了在屏幕上绘制的对象的结构。

Sphere.hpp

#include <Qt3DCore/QEntity>
#include <Qt3DExtras/QSphereMesh>
#include <Qt3DCore/QTransform>
#include <Qt3DExtras/QPhongMaterial>

class Sphere : public Qt3DCore::QEntity
{
public:
    Sphere();
    ~Sphere();
    void Color(const QColor& color);
    void Position(const QVector3D &position);
private:
    Qt3DExtras::QSphereMesh* mesh;
    Qt3DExtras::QPhongMaterial* material;
    Qt3DCore::QTransform* transform;
};

Sphere.cpp

#include "Sphere.hpp"

Sphere::Sphere() :
        mesh(new Qt3DExtras::QSphereMesh()),
        transform(new Qt3DCore::QTransform()),
        material(new Qt3DExtras::QPhongMaterial())

{
    this->addComponent(this->mesh);
    this->addComponent(this->transform);
    this->addComponent(this->material);
}

Sphere::~Sphere()
{
    this->removeComponent(this->mesh);
    this->removeComponent(this->transform);
    this->removeComponent(this->material);
    delete this->mesh;
    delete this->transform;
    delete this->material;
}

void Sphere::Color(const QColor &color) 
{
    this->material->setDiffuse(color);
}

void Sphere::Position(const QVector3D &position)
{
    this->transform->setTranslation(position);
}

在这里我创建一个线程，要在其中添加和删除循环中的点。

main.cpp

#include "Sphere.hpp"

#include <QApplication>
#include <QWidget>
#include <Qt3DExtras/qt3dwindow.h>
#include <Qt3DExtras/QSphereMesh>
#include <Qt3DExtras/QPhongMaterial>
#include <Qt3DCore/QEntity>
#include <Qt3DCore/QTransform>
#include <Qt3DRender/QCamera>
#include <Qt3DRender/QCameraLens>
#include <Qt3DRender/QPointLight>

#include <thread>
#include <chrono>
#include <vector>

std::vector<Sphere*> sphere_vec;
Qt3DCore::QEntity* g_root;

const int sphere_number = 100;

int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    auto view = new Qt3DExtras::Qt3DWindow();
    QWidget* container = QWidget::createWindowContainer(view);

    auto camera = view->camera();
    camera->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
    camera->setPosition(QVector3D(0,0,100));
    camera->setViewCenter(QVector3D(0,0,0));

    g_root = new Qt3DCore::QEntity();

    Qt3DCore::QEntity *lightEntity = new Qt3DCore::QEntity(g_root);
    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(camera->position());
    lightEntity->addComponent(lightTransform);

    view->setRootEntity(g_root);

    for(int i = 0; i < sphere_number;++i)
    {
        auto sphere = new Sphere();
        sphere_vec.push_back(sphere);
    }

    std::thread thr([]{

        for(int i = 0; i < sphere_number; ++i)
        {
            sphere_vec[i]->Position(QVector3D(i, 0, 0));
            sphere_vec[i]->setParent(g_root);
        }
        std::this_thread::sleep_for(std::chrono::seconds(0.33));

        for(int i = 0; i < sphere_number; ++i)
        {
            delete sphere_vec[i];
        }

    });

    container->show();

    int res = app.exec();
    thr.join();
    return res;
}