VTK屬性: 環境光

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2)
VTK_MODULE_INIT(vtkInteractionStyle)
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkProperty.h>
#include <vtkCamera.h>
#include <vtkLight.h>

namespace Ui {
class MainWindow;
}

//
// 環境光係數(Ambient): 光線照射到物體材質上，經過多次反射後最終遺留在環境中的光線強度，越大時，物體偏亮
// 漫反射係數(Diffuse): 光線照射到物體材質上，經過漫反射後形成的光線強度, 越大時，物體偏亮
// 鏡面反射係數(Specular): 光線照射到物體材質上，經過鏡面反射後形成的光線強度
// 鏡面指數(Specular Power): 取值範圍是0---128，該值越小，表示材質越是粗糙，當點光源發射的光線照射到上面時，可以產生較大的亮點，
// 該值越大，表示材質越是類似於鏡面，光源照射到上面後會產生較小的亮點；

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    void addAmbientSpheres();
    void addLight();
    void addCamera();
private:
    vtkSmartPointer<vtkRenderer> pRenderer;
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    pRenderer = vtkSmartPointer<vtkRenderer>::New();

    addAmbientSpheres();
    addLight();
    addCamera();

    ui->qvtkWidget->GetRenderWindow()->AddRenderer(pRenderer);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::addAmbientSpheres()
{
    vtkSmartPointer<vtkSphereSource> sphere = vtkSmartPointer<vtkSphereSource>::New();
    sphere->SetThetaResolution(100);
    sphere->SetPhiResolution(50);

    vtkSmartPointer<vtkPolyDataMapper> sphereMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
    sphereMapper->SetInputConnection(sphere->GetOutputPort());

    //
    vtkSmartPointer<vtkActor> sphere1 = vtkSmartPointer<vtkActor>::New();
    sphere1->SetMapper(sphereMapper);
    sphere1->GetProperty()->SetColor(1,0,0);
    sphere1->GetProperty()->SetAmbient(0.125);       // 環境光係數(Ambient): 光線照射到物體材質上，經過多次反射後最終遺留在環境中的光線強度，越大時，物體偏亮
    sphere1->GetProperty()->SetDiffuse(0.0);         // 漫反射係數(Diffuse): 光線照射到物體材質上，經過漫反射後形成的光線強度, 越大時，物體偏亮
    sphere1->GetProperty()->SetSpecular(0.0);        // 鏡面反射係數(Specular): 光線照射到物體材質上，經過鏡面反射後形成的光線強度
    // sphere1->GetProperty()->SetSpecularPower(64); // 鏡面指數(Specular Power): 取值範圍是0---128，該值越小，表示材質越是粗糙，當點光源發射的光線照射到上面時，可以產生較大的亮點，
                                                     // 該值越大，表示材質越是類似於鏡面，光源照射到上面後會產生較小的亮點；

    vtkSmartPointer<vtkActor> sphere2 = vtkSmartPointer<vtkActor>::New();
    sphere2->SetMapper(sphereMapper);
    sphere2->GetProperty()->SetColor(1,0,0);
    sphere2->GetProperty()->SetAmbient(0.25);
    sphere2->GetProperty()->SetDiffuse(0.0);
    sphere2->GetProperty()->SetSpecular(0.0);
    sphere2->AddPosition(1.25,0,0);

    vtkSmartPointer<vtkActor> sphere3 = vtkSmartPointer<vtkActor>::New();
    sphere3->SetMapper(sphereMapper);
    sphere3->GetProperty()->SetColor(1,0,0);
    sphere3->GetProperty()->SetAmbient(0.375);
    sphere3->GetProperty()->SetDiffuse(0.0);
    sphere3->GetProperty()->SetSpecular(0.0);
    sphere3->AddPosition(2.5,0,0);

    vtkSmartPointer<vtkActor> sphere4 = vtkSmartPointer<vtkActor>::New();
    sphere4->SetMapper(sphereMapper);
    sphere4->GetProperty()->SetColor(1,0,0);
    sphere4->GetProperty()->SetAmbient(0.5);
    sphere4->GetProperty()->SetDiffuse(0.0);
    sphere4->GetProperty()->SetSpecular(0.0);
    sphere4->AddPosition(3.75,0,0);

    vtkSmartPointer<vtkActor> sphere5 = vtkSmartPointer<vtkActor>::New();
    sphere5->SetMapper(sphereMapper);
    sphere5->GetProperty()->SetColor(1,0,0);
    sphere5->GetProperty()->SetAmbient(0.625);
    sphere5->GetProperty()->SetDiffuse(0.0);
    sphere5->GetProperty()->SetSpecular(0.0);
    sphere5->AddPosition(0.0,1.25,0);

    vtkSmartPointer<vtkActor> sphere6 = vtkSmartPointer<vtkActor>::New();
    sphere6->SetMapper(sphereMapper);
    sphere6->GetProperty()->SetColor(1,0,0);
    sphere6->GetProperty()->SetAmbient(0.75);
    sphere6->GetProperty()->SetDiffuse(0.0);
    sphere6->GetProperty()->SetSpecular(0.0);
    sphere6->AddPosition(1.25,1.25,0);

    vtkSmartPointer<vtkActor> sphere7 = vtkSmartPointer<vtkActor>::New();
    sphere7->SetMapper(sphereMapper);
    sphere7->GetProperty()->SetColor(1,0,0);
    sphere7->GetProperty()->SetAmbient(0.875);
    sphere7->GetProperty()->SetDiffuse(0.0);
    sphere7->GetProperty()->SetSpecular(0.0);
    sphere7->AddPosition(2.5,1.25,0);

    vtkSmartPointer<vtkActor> sphere8 = vtkSmartPointer<vtkActor>::New();
    sphere8->SetMapper(sphereMapper);
    sphere8->GetProperty()->SetColor(1,0,0);
    sphere8->GetProperty()->SetAmbient(1.0);
    sphere8->GetProperty()->SetDiffuse(0.0);
    sphere8->GetProperty()->SetSpecular(0.0);
    sphere8->AddPosition(3.75,1.25,0);

    pRenderer->AddActor(sphere1);
    pRenderer->AddActor(sphere2);
    pRenderer->AddActor(sphere3);
    pRenderer->AddActor(sphere4);
    pRenderer->AddActor(sphere5);
    pRenderer->AddActor(sphere6);
    pRenderer->AddActor(sphere7);
    pRenderer->AddActor(sphere8);
    pRenderer->SetBackground(0.1, 0.2, 0.4);
}

void MainWindow::addLight()
{
    vtkSmartPointer<vtkLight> light = vtkSmartPointer<vtkLight>::New();
    light->SetFocalPoint(1.875,0.6125,0);
    light->SetPosition(0.875,1.6125,1);

    pRenderer->AddLight(light);
}

void MainWindow::addCamera()
{
    pRenderer->GetActiveCamera()->SetFocalPoint(0,0,0);
    pRenderer->GetActiveCamera()->SetPosition(0,0,1);
    pRenderer->GetActiveCamera()->SetViewUp(0,1,0);
    pRenderer->GetActiveCamera()->ParallelProjectionOn(); // 啓用正交投影
    pRenderer->ResetCamera();
    pRenderer->GetActiveCamera()->SetParallelScale(1.5);
}

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <layout class="QHBoxLayout" name="horizontalLayout">
    <item>
     <widget class="QVTKWidget" name="qvtkWidget"/>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>400</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <customwidgets>
  <customwidget>
   <class>QVTKWidget</class>
   <extends>QWidget</extends>
   <header>QVTKWidget.h</header>
  </customwidget>
 </customwidgets>
 <resources/>
 <connections/>
</ui>

自下而上，從左到右，環境光係數逐漸增大