剪裁

　　剪裁的操作基本上和剪下一樣，需要使用一把“刀”（隱函式）並設定剪裁值。輸入的資料集被分成了兩部分：裁下的部分和裁掉的部分。預設只產生裁下的部分這個輸出。

示例演示

CMakeLists.txt檔案程式碼如下：

CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
PROJECT(ClipExample)
FIND_PACKAGE(VTK REQUIRED)
INCLUDE(${VTK_USE_FILE})
ADD_EXECUTABLE(ClipExample Clip.cpp)
TARGET_LINK_LIBRARIES(ClipExample ${VTK_LIBRARIES}
 
)

C++程式碼：

#include "vtkActor.h"
#include "vtkXMLPolyDataReader.h"
#include "vtkClipPolyData.h"
#include "vtkPlane.h"
#include "vtkPolyData.h"
#include "vtkPolyDataMapper.h"
#include "vtkPolyDataNormals.h"
#include "vtkProperty.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
 

#include "vtkRenderer.h"
#include "vtkSmartPointer.h"
#include "vtkInteractorStyleTrackballCamera.h"

int main()
{
    //read input data
    vtkSmartPointer<vtkXMLPolyDataReader> reader = vtkSmartPointer<vtkXMLPolyDataReader>::New();
    reader->SetFileName("E:\\TestData\\cow.vtp");

    vtkSmartPointer<
 
vtkPolyDataNormals> cow_normals = vtkSmartPointer<vtkPolyDataNormals>::New();
    cow_normals->SetInputConnection(reader->GetOutputPort());

    vtkSmartPointer<vtkPlane> plane = vtkSmartPointer<vtkPlane>::New();
    plane->SetOrigin(0.25, 0.0, 0.0);
    plane->SetNormal(-1, -1, 0);

    vtkSmartPointer<vtkClipPolyData> clipper = vtkSmartPointer<vtkClipPolyData>::New();
    clipper->SetInputConnection(cow_normals->GetOutputPort());
    clipper->SetClipFunction(plane);
    clipper->GenerateClipScalarsOn();
    clipper->GenerateClippedOutputOn();
    clipper->SetValue(0.5);

    vtkSmartPointer<vtkPolyDataMapper> clip_mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
    clip_mapper->SetInputConnection(clipper->GetOutputPort());
    clip_mapper->ScalarVisibilityOff();

    vtkSmartPointer<vtkProperty> backProp = vtkSmartPointer<vtkProperty>::New();
    backProp->SetDiffuseColor(1.00, 0.388, 0.278);

    vtkSmartPointer<vtkActor> clip_actor = vtkSmartPointer<vtkActor>::New();
    clip_actor->SetMapper(clip_mapper);
    clip_actor->GetProperty()->SetColor(.200, .631, .788);
    clip_actor->SetBackfaceProperty(backProp);


    vtkSmartPointer<vtkPolyDataMapper> rest_mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
    rest_mapper->SetInputConnection(clipper->GetClippedOutputPort());
    rest_mapper->ScalarVisibilityOff();

    vtkSmartPointer<vtkActor> rest_actor = vtkSmartPointer<vtkActor>::New();
    rest_actor->SetMapper(rest_mapper);
    rest_actor->GetProperty()->SetRepresentationToWireframe();


    vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
    renderer->AddActor(clip_actor);
    renderer->AddActor(rest_actor);
    renderer->SetBackground(1.0, 1.0, 1.0);


    vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New();
    renWin->AddRenderer(renderer);
    renWin->SetSize(640, 480);
    renWin->Render();
    renWin->SetWindowName("ClipExample");

    vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
    iren->SetRenderWindow(renWin);

    vtkSmartPointer<vtkInteractorStyleTrackballCamera> style =
        vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
    iren->SetInteractorStyle(style);

    iren->Initialize();
    iren->Start();

    return EXIT_SUCCESS;
}

執行結果：

圖中顏色顯示部分是裁下的部分PolyData資料，而裁掉的部分以線框的形式顯示。