VTK 显示3D网格线

在VTK9.1.0在Windows10+VS2019+Qt 5.15.2环境下编译安装的Qt例子中，想显示球体表面的网格线。

通过vtkExtractEdges来实现显示全部网格线

    QSurfaceFormat::setDefaultFormat(QVTKOpenGLNativeWidget::defaultFormat());

    vtkNew<vtkRenderer> renderer;
    vtkNew<vtkNamedColors> colors;

    vtkNew<vtkSphereSource> sphereSource;

    {
        //球体
        vtkNew<vtkPolyDataMapper> sphereMapper;
        sphereMapper->SetInputConnection(sphereSource->GetOutputPort());

        vtkNew<vtkActor> sphereActor;
        sphereActor->SetMapper(sphereMapper);
        sphereActor->GetProperty()->SetColor(colors->GetColor4d("Tomato").GetData());

        renderer->AddActor(sphereActor);
    }

    {
        //网格线
        vtkNew<vtkExtractEdges> extractEdges;
        extractEdges->SetInputConnection(sphereSource->GetOutputPort());

        vtkNew<vtkPolyDataMapper> sphereMapper;
        sphereMapper->SetInputConnection(extractEdges->GetOutputPort());
        vtkNew<vtkActor> sphereActor;
        sphereActor->SetMapper(sphereMapper);
        sphereActor->GetProperty()->SetColor(colors->GetColor4d("Black").GetData());

        renderer->AddActor(sphereActor);
    }

    renderer->SetBackground(colors->GetColor3d("SteelBlue").GetData());
    vtkNew<vtkGenericOpenGLRenderWindow> renderWindow;
    renderWindow->AddRenderer(renderer);
    renderWindow->SetWindowName("RenderWindowNoUIFile");
    ui.vtk_main->setRenderWindow(renderWindow);

如下图所示：

还可以通过vtkFeatureEdges来显示特定的网格线：

1.边界(boundary)：只被一个多边形使用的边，或者直线单元；
2.非流行(non-manifold)：被三个以上的多边形共用的边；
3.特征边(feature edges)：被两个三角形使用，并且两个三角形之间的夹角大于特征角度（可自行设置此角度）；
4.流行边(manifold edges)：只被两个多边形使用的边。