，

 

        本例 vtkCutter可以配合隐式函数截取数据使用vtkPlane隐式函数配合vtkWidget截取任意平面。

1.读入数据

Create(vtkMultiBlockPLOT3DReader, reader);
    reader->SetXYZFileName("G:/Temp/vtkTest/combxyz.bin");
    reader->SetQFileName("G:/Temp/vtkTest/combq.bin");
    reader->SetScalarFunctionNumber(100);
    reader->Update();

        可以使用其他类型的数据测试。读取的数据文件在《VTK—vtkStructuredGrid提取维度面数据》文章中上传过。

2.定位截取平面

    vtkStructuredGrid *grid = (vtkStructuredGrid *) (reader->GetOutput()->GetBlock(0));
    double bounds[6] = {0};
    grid->GetBounds(bounds);

    Create(vtkPlane, plane);
    plane->SetOrigin((bounds[0] + bounds[1]) * 0.5,
                     (bounds[2] + bounds[3]) * 0.5,
                     (bounds[4] + bounds[5]) * 0.5);
    plane->SetNormal(0, 0, 1);

        初始时隐式函数平面定位在包络框中心，法线指向Z轴正方向。

3.配置vtkCutter

    Create(vtkCutter, cutter);
    cutter->SetCutFunction(plane);
    cutter->SetInputData(grid);

 4.使用vtkPlaneWidget交互定位切割平面

Create(vtkPlaneWidget, widget);
    widget->SetInteractor(inter);
    widget->SetDefaultRenderer(render1);
    widget->SetOrigin(plane->GetOrigin());
    widget->SetPoint1(bounds[1],
                      (bounds[2] + bounds[3]) * 0.5,
                      (bounds[4] + bounds[5]) * 0.5);
    widget->SetPoint2((bounds[0] + bounds[1]) * 0.5,
                      bounds[3],
                      (bounds[4] + bounds[5]) * 0.5);


    widget->EnabledOn();

    Create(mycallback, callback);
    callback->m_plane = plane;
    widget->AddObserver(vtkCommand::InteractionEvent, callback);

4.1小部件四角拖动可调整平面显示大小

 4.2鼠标左键点击平面可以任意拖动

4.3鼠标左键点击平面+CTRL键可使平面绕法线旋转

4.4拖动箭头可改变平面角度

4.5鼠标中键可以沿着法线拖动平面

5.完整代码

#include<vtkNew.h>
#include<vtkPlane.h>
#include<vtkCutter.h>
#include<vtkCamera.h>
#include<vtkAutoInit.h>
#include<vtkRenderer.h>
#include<vtkPlaneWidget.h>
#include<vtkRenderWindow.h>
#include<vtkDataSetMapper.h>
#include<vtkStructuredGrid.h>
#include<vtkMultiBlockDataSet.h>
#include<vtkRendererCollection.h>
#include<vtkRenderWindowInteractor.h>
#include<vtkMultiBlockPLOT3DReader.h>

VTK_MODULE_INIT(vtkRenderingOpenGL2)
VTK_MODULE_INIT(vtkInteractionStyle)
VTK_MODULE_INIT(vtkRenderingFreeType)


#define Create(type,name)\
    vtkNew<type> name;


class mycallback: public vtkCommand
{
public:
    static mycallback *New() {
        return new mycallback;
    }

    void Execute(vtkObject *caller, unsigned long eventId, void *callData) override
    {
        vtkPlaneWidget *widget = (vtkPlaneWidget *)caller;
        widget->GetPlane(m_plane);
    }
    vtkPlane *m_plane;
private:
    mycallback() {
        m_plane = nullptr;
    }
    ~mycallback() {}
};

int main()
{

    Create(vtkMultiBlockPLOT3DReader, reader);
    reader->SetXYZFileName("G:/Temp/vtkTest/combxyz.bin");
    reader->SetQFileName("G:/Temp/vtkTest/combq.bin");
    reader->SetScalarFunctionNumber(100);
    reader->Update();

    vtkStructuredGrid *grid = (vtkStructuredGrid *) (reader->GetOutput()->GetBlock(0));
    double bounds[6] = {0};
    grid->GetBounds(bounds);

    Create(vtkPlane, plane);
    plane->SetOrigin((bounds[0] + bounds[1]) * 0.5,
                     (bounds[2] + bounds[3]) * 0.5,
                     (bounds[4] + bounds[5]) * 0.5);
    plane->SetNormal(0, 0, 1);

    Create(vtkCutter, cutter);
    cutter->SetCutFunction(plane);
    cutter->SetInputData(grid);

    Create(vtkDataSetMapper, mapper1);
    mapper1->SetInputData(grid);
    Create(vtkActor, actor1);
    actor1->SetMapper(mapper1);
    Create(vtkRenderer, render1);
    render1->AddActor(actor1);
    render1->SetViewport(0, 0, 0.5, 1);

    Create(vtkDataSetMapper, mapper2);
    mapper2->SetInputConnection(cutter->GetOutputPort());
    Create(vtkActor, actor2);
    actor2->SetMapper(mapper2);
    Create(vtkRenderer, render2);
    render2->AddActor(actor2);
    render2->SetViewport(0.5, 0, 1, 1);

    Create(vtkRenderWindow, window);
    window->AddRenderer(render1);
    window->AddRenderer(render2);
    window->GetRenderers()->InitTraversal();

    Create(vtkRenderWindowInteractor, inter);
    inter->SetRenderWindow(window);


    Create(vtkCamera, camera);
    render1->SetActiveCamera(camera);
    render2->SetActiveCamera(camera);


    render1->ResetCamera();


    Create(vtkPlaneWidget, widget);
    widget->SetInteractor(inter);
    widget->SetDefaultRenderer(render1);
    widget->SetOrigin(plane->GetOrigin());
    widget->SetPoint1(bounds[1],
                      (bounds[2] + bounds[3]) * 0.5,
                      (bounds[4] + bounds[5]) * 0.5);
    widget->SetPoint2((bounds[0] + bounds[1]) * 0.5,
                      bounds[3],
                      (bounds[4] + bounds[5]) * 0.5);


    widget->EnabledOn();

    Create(mycallback, callback);
    callback->m_plane = plane;
    widget->AddObserver(vtkCommand::InteractionEvent, callback);


    inter->Start();
    return 0;
}