QT5:3D

在QT上绘制3D总共有三种方法：

用QT 3D模块进行支持3D

引用OpenGL库来支持3D

引用VTK OSG等库来支持3D

一.QT 3D

1.头文件模块支持

//QT 3D

C++ aplication：
qmake .pro file这个配置文件中添加

QT += 3dcore 3drender 3dinput 3dlogic 3dextras 3danimation

Qt Quick applicaton:

QT += 3dcore 3drender 3dinput 3dlogic 3dextras qml quick 3dquick 3danimation


在引用头文件中包含

#include <Qt3DCore>
#include <Qt3DRender>
#include <Qt3DInput>
#include <Qt3DLogic>
#include <Qt3DExtras>
#include <Qt3DAnimation>

#include <Qt3DExtras>
#include <Qt3DCore>

int main(int argc, char* argv)
{
  QGuiApplication a(argc, argv);
  QUrl data = QUrl::fromLocalFile("1.stl");

  Qt3DExtras::Qt3DWindow view;

  Qt3DCore::QEntity* rootEntity = new Qt3DCore::QEntity;
  Qt3DCore::QEntity* flyingwedge = new Qt3DCore::QEntity;

  Qt3DExtras::QPhongMaterial* material = new Qt3DExtras::QPhongMaterial();
  material->setDiffuse(QColor(254, 254, 254));

  Qt3DRender::QMesh* flyingwedgeMesh = new Qt3DRender::QMesh;
  flyingwedgeMesh->setMeshName("FlyingWedge");
  flyingwedgeMesh->setSource(data);
  flyingwedge->addComponent(flyingwedgeMesh);
  flyingwedge->addComponent(material);

  Qt3DRender::QCamera* camera = view.camera();
  camera->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
  camera->setPosition(QVector3D(0, 0, 40.0f));
  camera->setUpVector(QVector3D(0, 1, 0));
  camera->setViewCenter(QVector3D(0, 0, 0));

  Qt3DCore::QEntity* lightEntity = new Qt3DCore::QEntity(rootEntity);
  Qt3DRender::QPointLight* light = new Qt3DRender::QPointLight(lightEntity);
  light->setColor("white");
  light->setIntensity(0.8f);
  light->addComponent(light);

  Qt3DCore::QTransform* lightTransform = new Qt3DCore::QTransform(lightEntity);
  lightTransform->setTranslation(camera->position());
  lightEntity->addComponent(lightTransform);

  Qt3DExtras::QOrbitCameraController* camController = new Qt3DExtras::QOrbitCameraController(rootEntity);
  camController->setLinearSpeed(50.0f);
  camController->setLookSpeed(180.0f);
  camController->setCamera(camera);

  view.setRootEntity(rootEntity);
  view.show();
  
  return a.exec();  
}

二.QT OpenGL

1.头文件模块支持

//QT OpenGL

#include <QtOpenGL>

QT += opengl

Qt中提供了QtOpenGL模块来显示3D图形
Qt提供了QGLWidget类来渲染OpenGL图形
继承的虚函数：
1.initializeGL():设置OpenGL渲染环境，定义显示列表等，该函数只在第一次调用resizeGL()或paintGL()前调用一次
2.resizeGL():设置OpenGL的视口、投影等，每次部件改变大小时都会调用该函数
3.paintGL():渲染OpenGL场景，每当部件需要更新时都会调用该函数