如何在VTK中设置两个管之间的区域颜色

Question

我在同一条线上创建了两个管，我的下一步是在两个管之间设置区域的颜色，但我不知道该怎么做。有帮助吗？先感谢您！我的代码如下所示。

#include <vtkSmartPointer.h>
#include <vtkVersion.h>

#include <vtkParametricFunctionSource.h>
#include <vtkTupleInterpolator.h>
#include <vtkTubeFilter.h>
#include <vtkParametricSpline.h>

#include <vtkDoubleArray.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPointData.h>

#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>


vtkSmartPointer<vtkActor> createTube(double rad1,double rad2,double rad3,double rad4,double rad5,double rad6)
{
    vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
    points->InsertPoint(0,1,0,0);
    points->InsertPoint(1,2,0.3,0);
    points->InsertPoint(2,3,0.1,0);
    points->InsertPoint(3,4,0.2,0);
    points->InsertPoint(4,5,0.5,0);
    points->InsertPoint(5,6,0.4,0);

    // Fit a spline to the points
    vtkSmartPointer<vtkParametricSpline> spline =
        vtkSmartPointer<vtkParametricSpline>::New();
    spline->SetPoints(points);
    vtkSmartPointer<vtkParametricFunctionSource> functionSource =
        vtkSmartPointer<vtkParametricFunctionSource>::New();
    functionSource->SetParametricFunction(spline);
    functionSource->SetUResolution(10 * points->GetNumberOfPoints());
    functionSource->Update();

    // Interpolate the scalars
    //double rad;
    vtkSmartPointer<vtkTupleInterpolator> interpolatedRadius =
        vtkSmartPointer<vtkTupleInterpolator> ::New();
    interpolatedRadius->SetInterpolationTypeToLinear();
    interpolatedRadius->SetNumberOfComponents(1);
    interpolatedRadius->AddTuple(0,&rad1);
    interpolatedRadius->AddTuple(1,&rad2);
    interpolatedRadius->AddTuple(2,&rad3);
    interpolatedRadius->AddTuple(3,&rad4);
    interpolatedRadius->AddTuple(4,&rad5);
    interpolatedRadius->AddTuple(5,&rad6);

    // Generate the radius scalars
    vtkSmartPointer<vtkDoubleArray> tubeRadius =
        vtkSmartPointer<vtkDoubleArray>::New();
    unsigned int n = functionSource->GetOutput()->GetNumberOfPoints();
    tubeRadius->SetNumberOfTuples(n);
    tubeRadius->SetName("TubeRadius");
    double tMin = interpolatedRadius->GetMinimumT();
    double tMax = interpolatedRadius->GetMaximumT();
    double r;
    for (unsigned int i = 0; i < n; ++i)
    {
        double t = (tMax - tMin) / (n - 1) * i + tMin;
        interpolatedRadius->InterpolateTuple(t, &r);
        tubeRadius->SetTuple1(i, r);
    }

    // Add the scalars to the polydata
    vtkSmartPointer<vtkPolyData> tubePolyData =
        vtkSmartPointer<vtkPolyData>::New();
    tubePolyData = functionSource->GetOutput();
    tubePolyData->GetPointData()->AddArray(tubeRadius);
    tubePolyData->GetPointData()->SetActiveScalars("TubeRadius");

    // Create the tubes
    vtkSmartPointer<vtkTubeFilter> tuber =
        vtkSmartPointer<vtkTubeFilter>::New();
    tuber->SetInput(tubePolyData);
    tuber->SetNumberOfSides(20);
    tuber->SetVaryRadiusToVaryRadiusByAbsoluteScalar();

    vtkSmartPointer<vtkPolyDataMapper> tubeMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
    tubeMapper->SetInputConnection(tuber->GetOutputPort());
    tubeMapper->SetScalarRange(tubePolyData->GetScalarRange());

    //vtkSmartPointer<vtkActor> lineActor = vtkSmartPointer<vtkActor>::New();
    //lineActor->SetMapper(lineMapper);
    vtkSmartPointer<vtkActor> tubeActor = vtkSmartPointer<vtkActor>::New();
    tubeActor->SetMapper(tubeMapper);

    return tubeActor;
}


int main()
{
    vtkSmartPointer<vtkActor> tubeActor_1 = vtkSmartPointer<vtkActor>::New();
    tubeActor_1= createTube(0.15,0.14,0.13,0.12,0.11,0.10);

    vtkSmartPointer<vtkActor> tubeActor_2 = vtkSmartPointer<vtkActor>::New();
    tubeActor_2= createTube(0.5,0.155,0.145,0.145,0.125,0.115);
    //tubeActor_2->GetProperty()->SetOpacity(0.25);

    // Setup render window, renderer, and interactor
    vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
    vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
    renderWindow->AddRenderer(renderer);
    vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
    renderWindowInteractor->SetRenderWindow(renderWindow);
    renderer->AddActor(tubeActor_1);
    renderer->AddActor(tubeActor_2);
    renderer->SetBackground(1, 1, 1);

    renderWindow->Render();
    renderWindowInteractor->Start();

    return 0;
}