创建小部件

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下一个教程： 创建3D直方图

目标

在本教程中，您将学习如何

• 使用WidgetAccessor和VTK创建自己的小部件。
• 在可视化窗口中显示小部件。

代码

您可以从此处下载代码。

 
#ifndef USE_VTK
#include <iostream>
int main()
{
std::cout << "This sample requires direct compilation with VTK. Stop" << std::endl;
    return 0;
}
#else
#include <opencv2/viz.hpp>
#include <opencv2/viz/widget_accessor.hpp>
#include <iostream>
 
#include < vtkPoints.h>
#include < vtkTriangle.h>
#include < vtkCellArray.h>
#include < vtkPolyData.h>
#include < vtkPolyDataMapper.h>
#include < vtkIdList.h>
#include < vtkActor.h>
#include < vtkProp.h>
 
using namespace cv;
using namespace std;
 
static void help()
{
cout
<< "--------------------------------------------------------------------------" << endl
<< "This program shows how to create a custom widget. You can create your own "
<< "widgets by extending Widget2D/Widget3D, and with the help of WidgetAccessor." << endl
<< "Usage:" << endl
<< "./creating_widgets" << endl
<< endl;
}
 
class WTriangle : public viz::Widget3D
{
    public:
WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color = viz::Color::white());
};
 
WTriangle::WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color)
{
    // 创建一个三角形
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(pt1.x, pt1.y, pt1.z);
points->InsertNextPoint(pt2.x, pt2.y, pt2.z);
points->InsertNextPoint(pt3.x, pt3.y, pt3.z);
 
vtkSmartPointer<vtkTriangle> triangle = vtkSmartPointer<vtkTriangle>::New();
triangle->GetPointIds()->SetId(0,0);
triangle->GetPointIds()->SetId(1,1);
triangle->GetPointIds()->SetId(2,2);
 
vtkSmartPointer<vtkCellArray> cells = vtkSmartPointer<vtkCellArray>::New();
cells->InsertNextCell(triangle);
 
    // 创建一个多边形数据对象
vtkSmartPointer polyData = vtkSmartPointer::New();
 
    // 向多边形数据中添加几何体和拓扑结构
polyData->SetPoints(points);
polyData->SetPolys(cells);
 
    // 创建映射器和演员
vtkSmartPointer mapper = vtkSmartPointer::New();
#if VTK_MAJOR_VERSION <= 5
mapper->SetInput(polyData);
#else
mapper->SetInputData(polyData);
#endif
 
vtkSmartPointer actor = vtkSmartPointer::New();
actor->SetMapper(mapper);
 
    // 为了使可视化器能够访问，将此演员存储在小部件中
viz::WidgetAccessor::setProp(*this, actor);
 
    // 设置部件的颜色。这必须在WidgetAccessor之后调用。
setColor(color);
}
 
int main()
{
help();
 
    viz::Viz3d myWindow("Creating Widgets");
 
WTriangle tw(Point3f(0.0,0.0,0.0), Point3f(1.0,1.0,1.0), Point3f(0.0,1.0,0.0), viz::Color::red());
 
myWindow.showWidget("TRIANGLE", tw);
 
myWindow.spin();
 
    return 0;
}
#endif

说明

以下是程序的一般结构

• 扩展 Widget3D 类以创建一个新的 3D 小部件。

  class WTriangle : public viz::Widget3D
  {
      public:
  WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color = viz::Color::white());
  };

• 将 VTK 演员分配给小部件。

  // 为了使可视化器能够访问，将此演员存储在小部件中
  viz::WidgetAccessor::setProp(*this, actor);

• 设置小部件的颜色。

  // 设置部件的颜色。这必须在WidgetAccessor之后调用。
  setColor(color);

• 构建一个三角形小部件并在窗口中显示它。

   
  WTriangle tw(Point3f(0.0,0.0,0.0), Point3f(1.0,1.0,1.0), Point3f(0.0,1.0,0.0), viz::Color::red());
   
  myWindow.showWidget("TRIANGLE", tw);

结果

以下是程序的结果。