QT3D场景的快速绘制

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本文来自于csdn，将基于QT3D当中的例程BASIC 3D当中的代码一步步的通过讲解并修改其代码可以真正实现一个基于QT的画布。

 Window *view = new Window();//window class
 QWidget *container = QWidget::createWindowContainer(view);
 QSize screenSize = view->screen()->size();
 container->setMinimumSize(QSize(100, 100));
 container->setMaximumSize(screenSize);
 

QWidget *widget = new QWidget;
 QHBoxLayout *hLayout = new QHBoxLayout(widget);//在widget中加入水平的layout
 QVBoxLayout *vLayout = new QVBoxLayout();//不用参数，因为垂直layout作为组件加入到水平layout当中，也就加入到了widget中
 vLayout->setAlignment(Qt::AlignTop);//在顶端对齐
 hLayout->addWidget(container, 1);//加入容器
 hLayout->addLayout(vLayout);
 

cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);

Qt3DCore::QEntity *rootEntity = new Qt3DCore::QEntity();//创建顶层实体rootEntity

Qt3DInput::QInputAspect *input = new Qt3DInput::QInputAspect;
 engine.registerAspect(input);
 Qt3DCore::QCamera *cameraEntity = new Qt3DCore::QCamera(rootEntity);//在新创建的rootEntity里面添加摄像机
 cameraEntity->setObjectName(QStringLiteral("cameraEntity"));
 
 cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
 cameraEntity->setPosition(QVector3D(0, 0, -20.0f));//设定摄像机初始位置
 cameraEntity->setUpVector(QVector3D(0, 1, 0));
 cameraEntity->setViewCenter(QVector3D(0, 0, 0));//设定一进入的中心点
 input->setCamera(cameraEntity);//使摄像机能左右转动

Qt3DRender::QFrameGraph *frameGraph = new Qt3DRender::QFrameGraph();

Qt3DRender::QForwardRenderer *forwardRenderer = new Qt3DRender::QForwardRenderer();

forwardRenderer->setCamera(cameraEntity);//架设摄像机

forwardRenderer->setClearColor(QColor(QRgb(0xff4d4f)));//设置前端背景颜色

frameGraph->setActiveFrameGraph(forwardRenderer);//激活frameGraph

rootEntity->addComponent(frameGraph);

// Cuboid shape data
 Qt3DRender::QCuboidMesh *cuboid = new Qt3DRender::QCuboidMesh();
 
 // CuboidMesh Transform
 Qt3DCore::QTransform *cuboidTransform = new Qt3DCore::QTransform();
 cuboidTransform->setScale(4.0f);
 cuboidTransform->setTranslation(QVector3D(4.0f, -4.0f, 0.0f));
 
 Qt3DRender::QPhongMaterial *cuboidMaterial = new Qt3DRender::QPhongMaterial();
 cuboidMaterial->setDiffuse(QColor(QRgb(0x665423)));
 
 //Cuboid
 m_cuboidEntity = new Qt3DCore::QEntity(m_rootEntity);
 m_cuboidEntity->addComponent(cuboid);
 m_cuboidEntity->addComponent(cuboidMaterial);
 m_cuboidEntity->addComponent(cuboidTransform);
 

QCheckBox *torusCB = new QCheckBox(widget);

torusCB->setChecked(true);

torusCB->setText(QStringLiteral("Torus"));

QObject::connect(torusCB, &QCheckBox::stateChanged,modifier, &SceneModifier::enableTorus);

 void SceneModifier::enableTorus(bool enabled)
 {
 m_torusEntity->setParent(enabled ? m_rootEntity : Q_NULLPTR);
 } 

#include <QApplication>
 #include "myglwidget.h"
 #include "scenemode.h"
 #include<Qt3DRender/qframegraph.h>
 #include <Qt3DRender/qforwardrenderer.h>
 #include<qcolor.h>
 
 int main(int argc, char *argv[])
 {
 QApplication app(argc, argv);
 
 SceneMode *defalut = new SceneMode;
 
 defalut->resize(400, 300);
 defalut->setWindowTitle(QStringLiteral("5G huge scale simulation"));//确定窗口标题
 defalut->show();
 
 return app.exec();
 }

#include "scenemode.h"

#include <QVBoxLayout>

#include <QtCore/QDebug>

SceneMode::SceneMode(QWidget *parent)

:QWidget(parent)

{ QWidget *container;

//isCameraEntityFlag = false;

screen = new MyGLWidget(); //先生成window类型，create()了，

但此时还未显示出来

rootEntity = new Qt3DCore::QEntity();

initConnection();

this->sizeHint();//初始化窗口大小

container = this->initWidget();

this->initEngine();

this->initCameraEntity();

this->initLight();

this->initFrameGraph();

this->initBasicEntity();

this->setEngine();

this->updateRatio(container);

this->initConnection2();//由于camera相关变量需要在

initCameraEntity相关函数之后才能调用，所以三个按键与

camera的联系不能写进initconnection函数当中

（2018年5月4号，今天工作结束）

qDebug() << "Basic is OK";

}

void SceneMode::initConnection()

{

connect(screen,SIGNAL(cameraLevel(int)),this,SLOT

(changeCameraLevel(int)));//滚轮（screen.h）改变视角

（changeCameraLevel中实现，还没看）--看到这里2018年3月18号

// connect(view1,SIGNAL(clicked(bool)),this,SLOT(sysView()));

// connect(view2,SIGNAL(clicked(bool)),this,SLOT(picView()));

// connect(view3,SIGNAL(clicked(bool)),this,SLOT(userView()));

}

void SceneMode::initConnection2()

{

connect(view1,SIGNAL(clicked(bool)),this,SLOT(sysView()));

connect(view2,SIGNAL(clicked(bool)),this,SLOT(picView()));

connect(view3,SIGNAL(clicked(bool)),this,SLOT(userView()));

connect(pic1,SIGNAL(picModes(int)),this,SLOT(pressx(int)));

}

QWidget* SceneMode::initWidget()

{

QHBoxLayout* displaylayout = new QHBoxLayout(this);//changed

QVBoxLayout* buttongroup = new QVBoxLayout;

displaylayout->setMargin(6);//控件与窗体的左右边距

是6个坐标轴单位据

this->setLayout(displaylayout);

QWidget *container = QWidget::createWindowContainer(screen);

//将window类放入容器里

QSize screenSize = screen->screen()->size();

container->setMinimumSize(QSize(100,100));

container->setMaximumSize(screenSize);

displaylayout->addWidget(container,1);//使得displaylayout能显示3D

container->show(); //最后再显示存放绘图的window

类的容器显示出来

return container;

}

void SceneMode::initEngine()

{

QVariantMap data;

this->engine = new Qt3DCore::QAspectEngine();

this->engine->registerAspect(new Qt3DRender::QRenderAspect());

this->input = new Qt3DInput::QInputAspect();

this->engine->registerAspect(this->input);

data.insert(QStringLiteral("surface"), QVariant::fromValue

(static_cast<QSurface *>(this->screen)));

data.insert(QStringLiteral("eventSource"), QVariant::fromValue

(this->screen));

this->engine->setData(data);

//89到96行尚未攻克 2018年3月20日

}

void SceneMode::initCameraEntity()

{

//qDebug() << "Camera is OK";

cameraEntity = new Qt3DCore::QCamera(rootEntity);

cameraEntity->setObjectName(QStringLiteral("cameraEntity"));

//qDebug() << "1";

cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);// void setPerspectiveProjection(float fieldOfView,

float aspect,float nearPlane, float farPlane);

yzaxisDelta = QVector3D(-7,-10,9);//调试出来

一个比较好的结果

camerapos = QVector3D(100,150,-90.0f);

camCenter = QVector3D(0,0,0);

// camera3dPosition = QVector3D(800.0f, 2000.0f, 4000.0f);

// camera3dCenter = QVector3D(800.0f, 0.0f, 0.0f);

cameraEntity->setPosition(camerapos);//cameraEntity->

setPosition(QVector3D(100, 150, -90.0f));

cameraEntity->setUpVector(QVector3D(0, 1, 0));

//UpVector表示了

你在建立视点坐标系时的摄像机向上的方向，

决定了坐标系该轴的

正值延伸方向(取±1）。

//levelDelta = QVector3D(0.0f, 0.5f, 0.0f);

//yaxisDelta = QVector3D(0.0f, 0.0f, 100.0f);

//视角中心与相机位置的差值

cameraEntity->setViewCenter(camCenter);

//摄影机投射的中心点,cameraEntity->setViewCenter(QVector3D(0,0,0));

input->setCamera(cameraEntity);

}

void SceneMode::initLight()

{

Qt3DRender::QSphereMesh* lightMesh = new Qt3DRender::

QSphereMesh(rootEntity); //设置光源：

把光源附着在某一Entity

上就可以确定移动位置

lightMesh->setRings(1);

lightMesh->setSlices(1);

lightMesh->setRadius(1);

Qt3DRender::QSpotLight* spotLight = new Qt3DRender::QSpotLight

(rootEntity); //可以共用 //SpotLight

聚光灯源设置方向、截止角、强度、衰减因子

spotLight->setColor(Qt::white); //DirectionalLight

平行光源设置方向、强度、衰减因子

spotLight->setDirection(QVector3D(0,0,0));

//PointLight点光源设置强度、衰减因子

spotLight->setIntensity(5); //位置都有附着的

实体Entity决定,表示强度

spotLight->setCutOffAngle(360);

spotLight->setAttenuation(QVector3D(0,0.02,0));

//衰减系数和强度是配套的

Qt3DCore::QTransform* lifht1Transform = new Qt3DCore::QTransform(rootEntity); //光源位置

lifht1Transform->setTranslation(QVector3D(0.0f, 10000.0f, 0.0f));

//向y轴正方向平移十个单位

}

void SceneMode::initFrameGraph()

{

Qt3DRender::QFrameGraph *frameGraph = new Qt3DRender::QFrameGraph();

Qt3DRender::QForwardRenderer *forwardRenderer = new Qt3DRender::QForwardRenderer();

forwardRenderer->setCamera(cameraEntity);

forwardRenderer->setClearColor(QColor(QRgb(0xffffff)));

frameGraph->setActiveFrameGraph(forwardRenderer);

rootEntity->addComponent(frameGraph);

}

void SceneMode::initBasicEntity()//设定基本实体

{

// Torus shape data

//! [0]

m_torus = new Qt3DRender::QTorusMesh();

m_torus->setRadius(1.0f);//圆环大小

m_torus->setMinorRadius(0.2f);//应该是从外向里的扩展大小

数越小则窟窿越大

m_torus->setRings(3);//设定多少等边形

m_torus->setSlices(300);//透明度设置，越大越不透明

//! [0]

// TorusMesh Transform

//! [1]

Qt3DCore::QTransform *torusTransform = new Qt3DCore::QTransform();

torusTransform->setScale(3.0f);//放缩比例，

越大则原有图像越大

torusTransform->setRotation(QQuaternion::fromAxisAndAngle

(QVector3D(0.0f, 1.0f, 0.0f), 55.0f));//

最后一个参数设置旋转角度

torusTransform->setTranslation(QVector3D(4.0f, 4.0f, 10.0f));

//x表示左右，y是上下，z表示前后（左正右负，

上正下负，后正前负）

//! [1]

//! [2]

Qt3DRender::QPhongMaterial *torusMaterial = new Qt3DRender:

QPhongMaterial();

torusMaterial->setDiffuse(QColor(QRgb(0xbeb3FF)));//设置颜色

//! [2]

// Torus

//! [3]

m_torusEntity = new Qt3DCore::QEntity(m_rootEntity);

m_torusEntity->addComponent(m_torus);

m_torusEntity->addComponent(torusMaterial);

m_torusEntity->addComponent(torusTransform);

//! [3]

// Cylinder shape data

Qt3DRender::QCylinderMesh *cylinder = new Qt3DRender::QCylinderMesh();

cylinder->setRadius(1);

cylinder->setLength(3);

cylinder->setRings(100);

cylinder->setSlices(20);

// CylinderMesh Transform

Qt3DCore::QTransform *cylinderTransform = new Qt3DCore::QTransform();

cylinderTransform->setScale(1.5f);

cylinderTransform->setRotation(QQuaternion::fromAxisAndAngle

(QVector3D(0.0f, 0.0f, 1.0f), 90.0f));

//x指的是单个物体的前后，

y指的是上下，z指的是物体的左右，最后的向量表示旋转的角度

cylinderTransform->setTranslation(QVector3D(-4.0f, 4.0f, -1.5));

Qt3DRender::QPhongMaterial *cylinderMaterial = new Qt3DRender::

QPhongMaterial();

cylinderMaterial->setDiffuse(QColor(QRgb(0x928327)));

// Cylinder

m_cylinderEntity = new Qt3DCore::QEntity(m_rootEntity);

m_cylinderEntity->addComponent(cylinder);

m_cylinderEntity->addComponent(cylinderMaterial);

m_cylinderEntity->addComponent(cylinderTransform);

// Cuboid shape data

Qt3DRender::QCuboidMesh *cuboid = new Qt3DRender::QCuboidMesh();

// CuboidMesh Transform

Qt3DCore::QTransform *cuboidTransform = new Qt3DCore::QTransform();

cuboidTransform->setScale(4.0f);

cuboidTransform->setTranslation(QVector3D(4.0f, -4.0f, 0.0f));

QPhongMaterial();

cuboidMaterial->setDiffuse(QColor(QRgb(0x665423)));

//Cuboid

m_cuboidEntity = new Qt3DCore::QEntity(m_rootEntity);

m_cuboidEntity->addComponent(cuboid);

m_cuboidEntity->addComponent(cuboidMaterial);

m_cuboidEntity->addComponent(cuboidTransform);

// Sphere shape data

Qt3DRender::QSphereMesh *sphereMesh = new Qt3DRender::QSphereMesh();

sphereMesh->setRings(20);

sphereMesh->setSlices(20);

sphereMesh->setRadius(2);

// Sphere mesh transform

Qt3DCore::QTransform *sphereTransform = new Qt3DCore::QTransform();

sphereTransform->setScale(1.3f);

sphereTransform->setTranslation(QVector3D(-4.0f, -4.0f, 0.0f));

Qt3DRender::QPhongMaterial *sphereMaterial = new Qt3DRender::

QPhongMaterial();

sphereMaterial->setDiffuse(QColor(QRgb(0xa69929)));

// Sphere

m_sphereEntity = new Qt3DCore::QEntity(m_rootEntity);

m_sphereEntity->addComponent(sphereMesh);

m_sphereEntity->addComponent(sphereMaterial);

m_sphereEntity->addComponent(sphereTransform);

//sphere shape data2

Qt3DRender::QSphereMesh *sphereMesh2 = new Qt3DRender::QSphereMesh();

sphereMesh2->setRings(100);

sphereMesh2->setSlices(10);

sphereMesh2->setRadius(1);

//Sphere transformation

// Qt3DCore::QTransform *sphereTransform2 = new Qt3DCore::QTransform();

// sphereTransform2->setScale(2.0f);

// sphereTransform2->setTranslation(QVector3D(-16.0f,-8.0f,2.0f));

Qt3DRender::QPhongMaterial *sphereMaterial2 = new Qt3DRender::

QPhongMaterial();

sphereMaterial2->setDiffuse(QColor(QRgb(0xFFFFFF)));

//加载预置大小，材料以及位置参数

//t_sphereEntity = new Qt3DCore::QEntity(m_rootEntity);

//t_sphereEntity->addComponent(sphereMesh2);

//t_sphereEntity->addComponent(sphereMaterial2);

//t_sphereEntity->addComponent(sphereTransform2);

carEntity1 = new carEntity(m_rootEntity);

carEntity1->transform()->setScale3D(QVector3D(10,10,10));

carEntity1->transform()->setTranslation(QVector3D(0,0,0));

}

void SceneMode::updateRatio(QWidget* ctn)

{

QSize widgetSize = ctn->size();

float aspectRatio = float(widgetSize.width()) / float

(widgetSize.height());

cameraEntity->lens()->setPerspectiveProjection(60.0f,

aspectRatio, 0.1f, 100000.0f);

}

QSize SceneMode::sizeHint() const

{

return QSize(1024*3, 768*3);

}

void SceneMode::setEngine()

{

this->engine->setRootEntity(rootEntity);

}

SceneMode::~SceneMode()

{

}