VTKcreate spline points
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定义5个点
double p[5][3] = 0.0, 4.0, 0.0,
2.0, 0.0, 0.0,
4.0, 2.0, 0.0,
6.0, 0.0, 0.0,
8.0, 4.0, 0.0 ;
定义500个插值点
示例代码：
double p[5][3] = 0.0, 4.0, 0.0,
2.0, 0.0, 0.0,
4.0, 2.0, 0.0,
6.0, 0.0, 0.0,
8.0, 4.0, 0.0 ;
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
for( int i = 0; i < 5; ++i )
points->InsertNextPoint( p[i] );
vtkSmartPointer<vtkParametricSpline> spline =
vtkSmartPointer<vtkParametricSpline>::New();
spline->SetPoints(points);
vtkSmartPointer<vtkPoints> betaPoints = vtkSmartPointer<vtkPoints>::New();
int index = 0;
int countOfDeltaPoints = 500;
double step = 1.0 / ( countOfDeltaPoints - 1 );
for( double i = 0; i <= 1; i = i + step )
double tmp[3] = i, 0, 0 ;
spline->Evaluate( tmp, tmp, NULL );
betaPoints->InsertPoint( index++, tmp );
使用vtkParametricFunctionSource的polyData，不用开发者自己来create points：
示例代码：
#include <vtkSmartPointer.h>
#include <vtkParametricFunctionSource.h>
#include <vtkParametricSpline.h>
#include <vtkCellArray.h>
#include <vtkCellData.h>
#include <vtkDoubleArray.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkTransformPolyDataFilter.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkTransform.h>
#include <vtkSphereSource.h>
#include <vtkNamedColors.h>
#include <vtkTextSource.h>
#include <vtkCoordinate.h>
#include <vtkPolyDataMapper2D.h>
#include <vtkActor2D.h>
#include <QString>
#include <iostream>
using namespace std;
int main(int, char *[])
vtkSmartPointer<vtkNamedColors> colors =
vtkSmartPointer<vtkNamedColors>::New();
double p[5][3] = 0.0, 4.0, 0.0,
2.0, 0.0, 0.0,
4.0, 2.0, 0.0,
6.0, 0.0, 0.0,
8.0, 4.0, 0.0 ;
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
for( int i = 0; i < 5; ++i )
points->InsertNextPoint( p[i] );
vtkSmartPointer<vtkParametricSpline> spline =
vtkSmartPointer<vtkParametricSpline>::New();
spline->SetPoints(points);
/*
* we can use this way to create some delta points on line.
*
vtkSmartPointer<vtkPoints> betaPoints = vtkSmartPointer<vtkPoints>::New();
int index = 0;
int countOfDeltaPoints = 500;
double step = 1.0 / ( countOfDeltaPoints - 1 );
for( double i = 0; i <= 1; i = i + step )
double tmp[3] = i, 0, 0 ;
spline->Evaluate( tmp, tmp, NULL );
betaPoints->InsertPoint( index++, tmp );
spline->SetPoints( betaPoints );
*/
vtkSmartPointer<vtkParametricFunctionSource> functionSource =
vtkSmartPointer<vtkParametricFunctionSource>::New();
functionSource->SetParametricFunction(spline);
functionSource->Update();
vtkPolyData* polyData = functionSource->GetOutput();
vtkPoints* splinePoints = polyData->GetPoints();
// Setup actor and mapper
vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(functionSource->GetOutputPort());
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetColor( 1, 0, 0 );
actor->GetProperty()->SetLineWidth(3.0);
// 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);
printf( "the count of spline points is %d\\n", splinePoints->GetNumberOfPoints() );
for( int i = 0; i < splinePoints->GetNumberOfPoints(); ++i )
vtkSmartPointer<vtkSphereSource> sphere = vtkSmartPointer<vtkSphereSource>::New();
sphere->SetRadius( 0.1 );
vtkSmartPointer<vtkPolyDataMapper> sphereMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
sphereMapper->SetInputConnection( sphere->GetOutputPort() );
vtkSmartPointer<vtkActor> sphereActor = vtkSmartPointer<vtkActor>::New();
sphereActor->SetMapper( sphereMapper );
sphereActor->GetProperty()->SetColor( 0, 0, 1 );
sphereActor->VisibilityOn();
sphereActor->SetPosition( splinePoints->GetPoint(i) );
renderer->AddActor( sphereActor );
// text 2D
vtkSmartPointer<vtkTextSource> text2D =
vtkSmartPointer<vtkTextSource>::New();
text2D->SetText( QString::number( i+1 ).toStdString().c_str() );
vtkSmartPointer<vtkTransform> text2DTransform =
vtkSmartPointer<vtkTransform>::New();
double *center = sphereActor->GetCenter();
text2DTransform->Translate( center[0], center[1] + 0.1, center[2] );
text2DTransform->Scale( 0.01, 0.01, 0.01 );
vtkSmartPointer<vtkTransformPolyDataFilter> text2DDataFilter =
vtkSmartPointer<vtkTransformPolyDataFilter>::New();
text2DDataFilter->SetTransform( text2DTransform );
text2DDataFilter->SetInputConnection( text2D->GetOutputPort() );
vtkSmartPointer<vtkCoordinate> coords =
vtkSmartPointer<vtkCoordinate>::New();
coords->SetCoordinateSystemToWorld();
vtkSmartPointer<vtkPolyDataMapper2D> text2DMapper =
vtkSmartPointer<vtkPolyDataMapper2D>::New();
text2DMapper->SetInputConnection( text2DDataFilter->GetOutputPort() );
text2DMapper->SetTransformCoordinate( coords );
vtkSmartPointer<vtkActor2D> text2DActor =
vtkSmartPointer<vtkActor2D>::New();
text2DActor->SetMapper( text2DMapper );
renderer->AddActor( text2DActor );
renderer->SetBackground(colors->GetColor3d("Silver").GetData());
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
现在，再创建一条线，使得两条线封闭。
接着，尝试将这些points作为平面的边线点，创造一个cell将points串起来，画出一个面。
这样沿着曲线画平面有一个问题：
曲面并不会100%的沿着边界点生成。
如下图：
#include <vtkSmartPointer.h>
#include <vtkParametricFunctionSource.h>
#include <vtkParametricSpline.h>
#include <vtkCellArray.h>
#include <vtkCellData.h>
#include <vtkDoubleArray.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkTransformPolyDataFilter.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkTransform.h>
#include <vtkSphereSource.h>
#include <vtkNamedColors.h>
#include <vtkTextSource.h>
#include <vtkCoordinate.h>
#include <vtkPolyDataMapper2D.h>
#include <vtkActor2D.h>
#include <vtkPolyDataNormals.h>
#include <vtkPointData.h>
#include <vtkFloatArray.h>
#include <QString>
#include <iostream>
using namespace std;
int main(int, char *[])
setbuf( stdout, NULL );
vtkSmartPointer<vtkNamedColors> colors =
vtkSmartPointer<vtkNamedColors>::New();
double p[5][3] = 0.0, 4.0, 0.0,
2.0, 0.0, 0.0,
4.0, 2.0, 0.0,
6.0, 0.0, 0.0,
8.0, 4.0, 0.0 ;
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
for( int i = 0; i < 5; ++i )
points->InsertNextPoint( p[i] );
vtkSmartPointer<vtkParametricSpline> spline =
vtkSmartPointer<vtkParametricSpline>::New();
spline->SetPoints(points);
double p2[5][3] = 0.0, 4.0, 0.0,
2.0, 4.0, 0.0,
4.0, 4.0, 0.0,
6.0, 4.0, 0.0,
8.0, 4.0, 0.0 ;
for( int i = 0; i < 5; ++i )
points->InsertNextPoint( p2[4 - i] );
/*
* we can use this way to create some delta points on line.
*
vtkSmartPointer<vtkPoints> betaPoints = vtkSmartPointer<vtkPoints>::New();
int index = 0;
int countOfDeltaPoints = 500;
double step = 1.0 / ( countOfDeltaPoints - 1 );
for( double i = 0; i <= 1; i = i + step )
double tmp[3] = i, 0, 0 ;
spline->Evaluate( tmp, tmp, NULL );
betaPoints->InsertPoint( index++, tmp );
spline->SetPoints( betaPoints );
*/
vtkSmartPointer<vtkParametricFunctionSource> functionSource =
vtkSmartPointer<vtkParametricFunctionSource>::New();
functionSource->SetParametricFunction(spline);
functionSource->SetUResolution( 60 ); // generate 61 points.
functionSource->GenerateNormalsOn();
functionSource->Update();
vtkPolyData* polyData = functionSource->GetOutput();
vtkPoints* splinePoints = polyData->GetPoints();
// Setup actor and mapper
vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(functionSource->GetOutputPort());
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetColor( 1, 0, 0 );
actor->GetProperty()->SetLineWidth(3.0);
// 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 );
printf( "the count of spline points is %d\\n", splinePoints->GetNumberOfPoints() );
for( int i = 0; i < splinePoints->GetNumberOfPoints(); ++i )
vtkSmartPointer<vtkSphereSource> sphere = vtkSmartPointer<vtkSphereSource>::New();
sphere->SetRadius( 0.1 );
vtkSmartPointer<vtkPolyDataMapper> sphereMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
sphereMapper->SetInputConnection( sphere->GetOutputPort() );
vtkSmartPointer<vtkActor> sphereActor = vtkSmartPointer<vtkActor>::New();
sphereActor->SetMapper( sphereMapper );
sphereActor->GetProperty()->SetColor( 0, 0, 1 );
sphereActor->VisibilityOn();
sphereActor->SetPosition( splinePoints->GetPoint(i) );
renderer->AddActor( sphereActor );
// text 2D
vtkSmartPointer<vtkTextSource> text2D =
vtkSmartPointer<vtkTextSource>::New();
text2D->SetText( QString::number( i+1 ).toStdString().c_str() );
vtkSmartPointer<vtkTransform> text2DTransform =
vtkSmartPointer<vtkTransform>::New();
double *center = sphereActor->GetCenter();
text2DTransform->Translate( center[0], center[1] + 0.1, center[2] );
text2DTransform->Scale( 0.01, 0.01, 0.01 );
vtkSmartPointer<vtkTransformPolyDataFilter> text2DDataFilter =
vtkSmartPointer<vtkTransformPolyDataFilter>::New();
text2DDataFilter->SetTransform( text2DTransform );
text2DDataFilter->SetInputConnection( text2D->GetOutputPort() );
vtkSmartPointer<vtkCoordinate> coords =
vtkSmartPointer<vtkCoordinate>::New();
coords->SetCoordinateSystemToWorld();
vtkSmartPointer<vtkPolyDataMapper2D> text2DMapper =
vtkSmartPointer<vtkPolyDataMapper2D>::New();
text2DMapper->SetInputConnection( text2DDataFilter->GetOutputPort() );
text2DMapper->SetTransformCoordinate( coords );
vtkSmartPointer<vtkActor2D> text2DActor =
vtkSmartPointer<vtkActor2D>::New();
text2DActor->SetMapper( text2DMapper );
renderer->AddActor( text2DActor );
// create cell to form plane
vtkSmartPointer<vtkCellArray> poly = vtkSmartPointer<vtkCellArray>::New();
const int length = splinePoints->GetNumberOfPoints();
vtkIdType pts[ length ];
for( int i = 0; i < length; ++i )
pts[i] = i;
poly->InsertNextCell( length, pts );
vtkSmartPointer<vtkPolyData> planePd = vtkSmartPointer<vtkPolyData>::New();
planePd->SetPoints( splinePoints );
planePd->SetPolys( poly );
vtkSmartPointer<vtkPolyDataMapper> planeMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
planeMapper->SetInputData( planePd );
vtkSmartPointer<vtkActor> planeActor =
vtkSmartPointer<vtkActor>::New();
planeActor->SetMapper( planeMapper );
renderer->AddActor( planeActor );
renderer->SetBackground(colors->GetColor3d("Silver").GetData());
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
想要精确地画出曲面，可以使用微积分模型，利用这些边界点画出一个个小的四边形作为不同的cell，然后将这些不同的cell插入到vtkCellArray中。最后再构造vtkPolyData，mapper，actor等。
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