QT3D学习笔记——圆台、圆锥

类名	作用
Qt3DWindow	3D渲染窗口容器
QEntity	场景中的实体（对象或容器）
QCamera	控制观察视角
QPointLight	点光源
QConeMesh	圆锥几何网格
QTransform	控制实体的位置/旋转/缩放
QPhongMaterial	Phong光照材质（定义颜色、反光等）
QFirstPersonCameraController	第一人称相机控制器（WASD+鼠标控制）

Qt3DWindow（3D 窗口）

│

├─ RootEntity (QEntity 根实体)

│ ├─ Camera (QCamera 相机)

│ │ ├─ Lens (镜头：透视投影参数)

│ │ └─ Controller (控制器：WASD+鼠标控制)

│ │

│ ├─ Light (光源)

│ │ ├─ QPointLight(点光源：颜色/强度)

│ │ └─ QTransform (变换：光源位置)

│ │

│ └─ Cone (3d 圆锥实体）

│ ├─ QConeMesh (网格：几何图形)

│ ├─ QPhongMaterial (材质：颜色/反光)

│ └─ QTransform (变换：位置/旋转)

│

└─ FrameGraph (渲染管线：背景色/渲染设置)

//#include "mainwindow.h"

//#include "FrustumWidget.h"
#include <QApplication>
#include <QtCore/QObject>
#include <QGuiApplication>

#include <Qt3DRender/qcamera.h>
#include <Qt3DCore/qentity.h>
#include <Qt3DRender/qcameralens.h>

#include <QtWidgets/QApplication>
#include <QtWidgets/QWidget>
#include <QtWidgets/QHBoxLayout>
#include <QtWidgets/QCheckBox>
#include <QtWidgets/QCommandLinkButton>
#include <QtGui/QScreen>

#include <Qt3DInput/QInputAspect>

#include <Qt3DExtras/qtorusmesh.h>
#include <Qt3DRender/qmesh.h>
#include <Qt3DRender/qtechnique.h>
#include <Qt3DRender/qmaterial.h>
#include <Qt3DRender/qeffect.h>
#include <Qt3DRender/qtexture.h>
#include <Qt3DRender/qrenderpass.h>
#include <Qt3DRender/qsceneloader.h>
#include <Qt3DRender/qpointlight.h>

#include <Qt3DCore/qtransform.h>
#include <Qt3DCore/qaspectengine.h>

#include <Qt3DRender/qrenderaspect.h>
#include <Qt3DExtras/qforwardrenderer.h>

#include <Qt3DExtras/qt3dwindow.h>
#include <Qt3DExtras/qfirstpersoncameracontroller.h>
#include <Qt3DExtras/QPhongMaterial>
#include <Qt3DExtras/QConeMesh>
#include <QText2DEntity>
// 创建坐标轴线
Qt3DCore::QEntity* createAxisLine(Qt3DCore::QEntity* parent,
                                  const QVector3D& start,
                                  const QVector3D& end,
                                  const QColor& color) {
    Qt3DCore::QEntity* axis = new Qt3DCore::QEntity(parent);

    // 顶点数据
    QByteArray vertexData;
    vertexData.resize(2 * 3 * sizeof(float)); // 2 points xyz
    float* ptr = reinterpret_cast<float*>(vertexData.data());
    *ptr++ = start.x(); *ptr++ = start.y(); *ptr++ = start.z();
    *ptr++ = end.x();   *ptr++ = end.y();   *ptr++ = end.z();

    // 几何体
    Qt3DCore::QGeometry* geometry = new Qt3DCore::QGeometry(axis);
    Qt3DCore::QBuffer* vertexBuffer = new Qt3DCore::QBuffer(geometry);
    vertexBuffer->setData(vertexData);

    Qt3DCore::QAttribute* positionAttr = new Qt3DCore::QAttribute(
        vertexBuffer,  // 直接传递缓冲区，不传递geometry
        Qt3DCore::QAttribute::defaultPositionAttributeName(),
        Qt3DCore::QAttribute::Float,
        3,  // 每个顶点的分量数（xyz=3）
        2   // 顶点数量（起点+终点=2）
        );
    geometry->addAttribute(positionAttr);  // 手动添加到geometry

    // 渲染器
    Qt3DRender::QGeometryRenderer* line = new Qt3DRender::QGeometryRenderer(axis);
    line->setGeometry(geometry);
    line->setPrimitiveType(Qt3DRender::QGeometryRenderer::Lines);

    // 材质
    Qt3DExtras::QPhongMaterial* material = new Qt3DExtras::QPhongMaterial(axis);
    material->setDiffuse(color);
    material->setAmbient(color);

    axis->addComponent(line);
    axis->addComponent(material);

    return axis;
}

// 添加坐标轴标签（需要Qt3DExtras模块）
void addAxisLabel(Qt3DCore::QEntity* parent,
                  const QString& text,
                  const QVector3D& position) {
    Qt3DExtras::QText2DEntity* label = new Qt3DExtras::QText2DEntity(parent);
    label->setText(text);
    label->setColor(Qt::black);
    label->setHeight(20);
    label->setWidth(30);

    Qt3DCore::QTransform* transform = new Qt3DCore::QTransform(label);
    transform->setTranslation(position);
    label->addComponent(transform);
}
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    //MainWindow w;
    //w.show();

    Qt3DExtras::Qt3DWindow *view = new Qt3DExtras::Qt3DWindow();//3D的渲染窗口,提供3D场景的显示容器
    view->defaultFrameGraph()->setClearColor(QColor(Qt::black));//设置视图背景色
    QWidget *widget = QWidget::createWindowContainer(view);
    QSize screenSize = view->screen()->size();
    widget->setMinimumSize(QSize(200, 100));
    widget->setMaximumSize(screenSize);
    widget->setWindowTitle(QStringLiteral("Basic shapes"));

    //3D中的基本实体类，代表场景中的一个对象或容器。
    Qt3DCore::QEntity *rootEntity = new Qt3DCore::QEntity();
    view->setRootEntity(rootEntity);

    //管理输入设备的抽象层,启用输入处理（如鼠标、键盘事件）
    Qt3DInput::QInputAspect *input = new Qt3DInput::QInputAspect;
    view->registerAspect(input);

    //控制3D场景的观察视角
    Qt3DRender::QCamera *cameraEntity = view->camera();
    cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f / 9.0f, 0.1f, 1000.0f);
    cameraEntity->setUpVector(QVector3D(0, 1, 0));//定义相机的"向上"方向（通常为Y轴 (0,1,0)）。
    cameraEntity->setPosition(QVector3D(0, 10.0f, 10.0f));//视点:观察者所处的位置。
    cameraEntity->setViewCenter(QVector3D(0, 0, 0));//观察目标点

    //高光控制
    Qt3DCore::QEntity *lightEntity = new Qt3DCore::QEntity(rootEntity);
    //点光源组件
    Qt3DRender::QPointLight *light = new Qt3DRender::QPointLight(lightEntity);
    light->setColor("white");
    light->setIntensity(1);
    lightEntity->addComponent(light);

    //定义3d实体的位置/旋转/缩放
    Qt3DCore::QTransform *lightTransform = new Qt3DCore::QTransform(lightEntity);
    lightTransform->setTranslation(cameraEntity->position());
    lightEntity->addComponent(lightTransform);

    //启用第一人称相机控制（通过WASD和鼠标移动相机）
    Qt3DExtras::QFirstPersonCameraController *camController = new Qt3DExtras::QFirstPersonCameraController(rootEntity);
    camController->setCamera(cameraEntity);

    // 第一个圆锥（底部圆锥）
    Qt3DCore::QEntity *m_coneEntity = new Qt3DCore::QEntity(rootEntity);
    Qt3DExtras::QConeMesh *cone = new Qt3DExtras::QConeMesh();
    cone->setTopRadius(0.5);
    cone->setBottomRadius(0.5);
    cone->setLength(1);  // 高度为1
    cone->setRings(50);
    cone->setSlices(20);

    Qt3DCore::QTransform *coneTransform = new Qt3DCore::QTransform();
    coneTransform->setScale(1.0);
    //coneTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    coneTransform->setTranslation(QVector3D(0.0f, 0.0f, 0.0f));  // 底部圆锥位于原点

    Qt3DExtras::QPhongMaterial *coneMaterial = new Qt3DExtras::QPhongMaterial();
    coneMaterial->setDiffuse(QColor(Qt::white));

    m_coneEntity->addComponent(cone);
    m_coneEntity->addComponent(coneMaterial);
    m_coneEntity->addComponent(coneTransform);

    // 第二个圆锥（顶部圆锥）
    Qt3DCore::QEntity *m_coneEntity1 = new Qt3DCore::QEntity(rootEntity);
    Qt3DExtras::QConeMesh *cone1 = new Qt3DExtras::QConeMesh();
    cone1->setTopRadius(0.5);
    cone1->setBottomRadius(0.5);
    cone1->setLength(1);  // 高度同样为1
    cone1->setRings(50);
    cone1->setSlices(20);

    Qt3DCore::QTransform *coneTransform1 = new Qt3DCore::QTransform();
    coneTransform1->setScale(1.0);
    //coneTransform1->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    // 将第二个圆锥放在第一个圆锥的顶部
    // Y轴偏移 = 第一个圆锥的高度 + 第二个圆锥高度的一半（因为旋转后中心点在几何中心）
    coneTransform1->setTranslation(QVector3D(0.0f, 1.0f, 0.0f));

    Qt3DExtras::QPhongMaterial *coneMaterial1 = new Qt3DExtras::QPhongMaterial();
    coneMaterial1->setDiffuse(QColor(Qt::white));

    m_coneEntity1->addComponent(cone1);
    m_coneEntity1->addComponent(coneMaterial1);
    m_coneEntity1->addComponent(coneTransform1);

    widget->show();
    widget->resize(500, 500);

    return a.exec();
}