vtk中插值拟合成线的函数

逃离我推掉我的手 2022-06-09 10:57 87阅读 0赞

根据点进行样条插值拟合成曲线

vtkPoints *points = vtkPoints::New();
    
        points->InsertPoint(0, 0.0, 0.0, 0.0);
        points->InsertPoint(1, 1.0, 1.0, 1.0);
        points->InsertPoint(2, 1.0, 0.0, 0.0);
        points->InsertPoint(3, 1.0, 0.0, 1.0);
    
        //插值为样条曲线  
        vtkParametricSpline *spline = vtkParametricSpline::New();
        spline->SetPoints(points);
        spline->ClosedOff();
        vtkParametricFunctionSource *splineSource = vtkParametricFunctionSource::New();
        splineSource->SetParametricFunction(spline);
    
        vtkPolyDataMapper *splineMapper = vtkPolyDataMapper::New();
        splineMapper->SetInputConnection(splineSource->GetOutputPort());
    
        vtkActor *splineActor = vtkActor::New();
        splineActor->SetMapper(splineMapper);
        splineActor->GetProperty()->SetColor(0.3800, 0.7000, 0.1600);

根据vtk官网中的描述：  
`*vtkParametricSpline is a parametric function for 1D interpolating splines. vtkParametricSpline maps the single parameter u into a 3D point (x,y,z) using three instances of interpolating splines. This family of 1D splines is guaranteed to be parameterized in the interval [0,1]. Attempting to evaluate outside this interval will cause the parameter u to be clamped in the range [0,1]. When constructed, this class creates instances of vtkCardinalSpline for each of the x-y-z coordinates. The user may choose to replace these with their own instances of subclasses of vtkSpline*.`

vtkParametricSpline 为vtkCardinalSpline，使用者也可以继承vktSpline这个类来写一个函数做插值拟合。  
[插值结果][Link 1]当然还有一个继承Hermite的为vtkKochenekSpline，vtk官网还提供了vtkSCurve S型曲线拟合的方式，三者测试结果如下图所示：  
![这里写图片描述][SouthEast]  
后续还需要分析这三者插值的方式，具体到数学公式这一块。

[Link 1]: http://tieba.baidu.com/p/4671508109?pid=94226951599&cid=0#94226951599
[SouthEast]: /images/20220609/34e7da804f6545518dc92812931c17a3.png