vtkSpline这个类怎么使用啊，我以为和vtkLine差不多，可是和我想的不一样。我知道怎么用vtkSplineWidget，但是不知道怎么vtkSpline。

去看看这些：
vtkCardinalSpline vtkKochenekSpline vtkParametricSpline vtkSCurveSpline.

看了官方的例子，vtkCardinalSpline、vtkKochenekSpline、vtkSCurveSpline的使用如下：
#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkProperty.h>
#include <vtkPoints.h>
#include <vtkPointSource.h>
#include <vtkSpline.h>
#include <vtkCardinalSpline.h>
#include <vtkParametricSpline.h>
#include <vtkParametricFunctionSource.h>
#include <vtkKochanekSpline.h>
#include <vtkSCurveSpline.h>
int main()
{
/*
//1.原例子设置点的方式
vtkSmartPointer<vtkPointSource> pointSource =
vtkSmartPointer<vtkPointSource>::New();
pointSource->SetNumberOfPoints(5);
pointSource->Update();
vtkPoints* points = pointSource->GetOutput()->GetPoints();
*/
//2.我试下设置定点，也可以运行
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(0,0,0);
points->InsertNextPoint(0,1,0);
points->InsertNextPoint(1,1,0);
points->InsertNextPoint(1,0,0);
points->InsertNextPoint(0,0,0);
/*//scurve spline
vtkSmartPointer<vtkSCurveSpline> xSpline =
vtkSmartPointer<vtkSCurveSpline>::New();
vtkSmartPointer<vtkSCurveSpline> ySpline =
vtkSmartPointer<vtkSCurveSpline>::New();
vtkSmartPointer<vtkSCurveSpline> zSpline =
vtkSmartPointer<vtkSCurveSpline>::New();
*/
/*
//cardinal spline
vtkSmartPointer<vtkCardinalSpline> xSpline = vtkSmartPointer<vtkCardinalSpline>::New();
vtkSmartPointer<vtkCardinalSpline> ySpline = vtkSmartPointer<vtkCardinalSpline>::New();
vtkSmartPointer<vtkCardinalSpline> zSpline = vtkSmartPointer<vtkCardinalSpline>::New();
*/
//kochanek spline
vtkSmartPointer<vtkKochanekSpline> xSpline = vtkSmartPointer<vtkKochanekSpline>::New();
vtkSmartPointer<vtkKochanekSpline> ySpline = vtkSmartPointer<vtkKochanekSpline>::New();
vtkSmartPointer<vtkKochanekSpline> zSpline = vtkSmartPointer<vtkKochanekSpline>::New();
vtkSmartPointer<vtkParametricSpline> spline =
vtkSmartPointer<vtkParametricSpline>::New();
spline->SetXSpline(xSpline);
spline->SetYSpline(ySpline);
spline->SetZSpline(zSpline);
spline->SetPoints(points);
vtkSmartPointer<vtkParametricFunctionSource> functionSource =
vtkSmartPointer<vtkParametricFunctionSource>::New();
functionSource->SetParametricFunction(spline);
functionSource->Update();
// Setup actor and mapper
vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(functionSource->GetOutputPort());
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
// 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(actor);
renderer->SetBackground(0.1,0.2,0.3);
renderWindow->Render();
renderWindowInteractor->Start();
return 0;
}
运行结果：
vtkSCurveSpline：
vtkCardinalSpline：
vtkKochenekSpline：

vtkParametricSpline的使用则更加简单：
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(0,0,0);
points->InsertNextPoint(0,1,0);
points->InsertNextPoint(1,1,0);
points->InsertNextPoint(1,0,0);
points->InsertNextPoint(0,0,0);
vtkSmartPointer<vtkParametricSpline> spline =
vtkSmartPointer<vtkParametricSpline>::New();
spline->SetPoints(points);
vtkSmartPointer<vtkParametricFunctionSource> functionSource =
vtkSmartPointer<vtkParametricFunctionSource>::New();
functionSource->SetParametricFunction(spline);
functionSource->Update();
// Setup actor and mapper
vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(functionSource->GetOutputPort());
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
// 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(actor);
renderer->SetBackground(0.1,0.2,0.3);
renderWindow->Render();
renderWindowInteractor->Start();
运行结果：

但是这不是我要的效果啊，我希望可以像使用vtkSplineWidget一样可以调节区域范围，如图：
但是好像vtkSplineWidget这个类好像不能在图像上使用，或者是我的代码有问题？
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(0,0,0);
points->InsertNextPoint(1,0,0);
points->InsertNextPoint(1,1,0);
points->InsertNextPoint(0,1,0);
points->InsertNextPoint(0,0,0);
vtkSmartPointer<vtkProperty> property = vtkSmartPointer<vtkProperty>::New();
property->SetLineWidth(1);
property->SetColor(1.0,0,0);
property->SetPointSize(0.5);
vtkSmartPointer<vtkSplineWidget> splineWidget = vtkSmartPointer<vtkSplineWidget>::New();
splineWidget->InitializeHandles(points);
splineWidget->SetLineProperty(property);
vtkSmartPointer<vtkJPEGReader> reader = vtkSmartPointer<vtkJPEGReader>::New();
reader->SetFileName("C:\\Users\\Administrator\\Desktop\\lyt.jpg");
reader->Update();
vtkSmartPointer<vtkImageData> image = vtkSmartPointer<vtkImageData>::New();
image = reader->GetOutput();
vtkSmartPointer<vtkImageActor> actor = vtkSmartPointer<vtkImageActor>::New();
actor->SetInput(image);
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
renderer->SetBackground(0.1,0.2,0.4);
renderer->AddActor(actor);
vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New();
renWin->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow(renWin);
renWin->SetSize(640,480);
splineWidget->SetInteractor(iren);
iren->Initialize();
renWin->Render();
splineWidget->On();
iren->Start();
运行结果：
为什么呢？

我想你需要的是这个：vtkContourWidget
试试看

时过一年 ..
请问楼主 SCurve样条的二次或者三次曲线 如何设置..
CardinalSpline和 kochanekspline 又是啥啊..