+
−#include <vtkPoints.h>
+
−#include <vtkPointData.h>
+
−#include <vtkDelaunay2D.h>
+
−#include <vtkLookupTable.h>
+
−
+
−#include <vtkPolyData.h>
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−#include <vtkPolyDataNormals.h>
+
−#include <vtkPolyDataMapper.h>
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−
+
−#include <vtkWarpScalar.h>
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−
+
−#include <vtkCamera.h>
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−#include <vtkActor.h>
+
−#include <vtkRenderWindow.h>
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−#include <vtkRenderWindowInteractor.h>
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−#include <vtkRenderer.h>
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−
+
−#include <vtkInteractorStyleTerrain.h>
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−
+
−#include <vtkSmartPointer.h>
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−#include <vtkDoubleArray.h>
+
−
+
−#include <vtkGraphicsFactory.h>
+
−#include <vtkImagingFactory.h>
+
−#include <vtkWindowToImageFilter.h>
+
−#include <vtkPNGWriter.h>
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−
+
−typedef double (*Func3d)(double, double);
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−
+
−void InitOffscreen(bool offscreen);
+
−vtkSmartPointer<vtkDelaunay2D> TriangulateTerrain(Func3d func);
+
−void PlotPoints(vtkSmartPointer<vtkDelaunay2D> delaunay, bool offscreen=true);
+
−
+
−double F(double x, double y)
+
−{
+
−  return atan(x*y*y);
+
−}
+
−
+
−int main (int argc, char ** argv)
+
−{
+
−	auto delaunay = TriangulateTerrain(&F);	
+
−  PlotPoints(delaunay,false);
+
−	return 0;
+
−}
+
−
+
−void InitOffscreen(bool offscreen)
+
−{
+
−  // Graphics Factory
+
−  vtkSmartPointer<vtkGraphicsFactory> graphics_factory
+
−    = vtkGraphicsFactory::New();
+
−  graphics_factory->SetOffScreenOnlyMode( offscreen );
+
−  graphics_factory->SetUseMesaClasses( offscreen );
+
−
+
−  // Imaging Factory
+
−  vtkSmartPointer<vtkImagingFactory>  imaging_factory
+
−    = vtkImagingFactory::New();
+
−  imaging_factory->SetUseMesaClasses( offscreen );
+
−}
+
−
+
−vtkSmartPointer<vtkDelaunay2D> TriangulateTerrain(Func3d func)
+
−{
+
−
+
−	vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
+
−  vtkSmartPointer<vtkDoubleArray> scalars = vtkSmartPointer<vtkDoubleArray>::New();
+
− 
+
−	unsigned int GridSize = 50;
+
−	for(double x = -3; x < 3; x += 6.0/GridSize)
+
−	{
+
−		for(double y = -3; y < 3; y += 6.0/GridSize)
+
−		{
+
−      double z = func(x,y);
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−			vtkIdType idx = points->InsertNextPoint(x, y, z);
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−      scalars -> InsertTuple(idx, &z);
+
−		}
+
−	}
+
− 
+
−	//add the grid points to a polydata object
+
−	vtkSmartPointer<vtkPolyData> polydata = vtkPolyData::New();
+
−	polydata->SetPoints(points);
+
−  polydata->GetPointData() -> SetScalars(scalars);
+
− 
+
−	//triangulate the grid points
+
−	vtkSmartPointer<vtkDelaunay2D> delaunay = vtkDelaunay2D::New();
+
−	delaunay->SetInput(polydata);
+
−	delaunay->Update();
+
−
+
−  return delaunay;
+
−}
+
−
+
−void PlotPoints(vtkSmartPointer<vtkDelaunay2D> delaunay, bool offscreen)
+
−{
+
−  InitOffscreen(offscreen);
+
−
+
−
+
−  //Normals for Gourad shading
+
−  vtkSmartPointer<vtkPolyDataNormals> normals = vtkPolyDataNormals::New();
+
−  normals -> SetInputConnection(delaunay ->GetOutputPort() );
+
−  normals -> SetFeatureAngle(60);
+
−
+
−  //Set the colours for the rendering
+
−  vtkSmartPointer<vtkLookupTable> lut = vtkLookupTable::New();
+
−  lut -> SetHueRange(0.66667, 0.0);
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−  lut -> SetNumberOfColors(256);
+
−  lut -> SetRampToLinear();
+
−  lut -> Build();
+
−
+
−  
+
−	// map the contours to graphical primitives
+
−	vtkSmartPointer<vtkPolyDataMapper> contMapper = vtkPolyDataMapper::New();
+
−  contMapper->SetInput(normals -> GetOutput() );
+
−  contMapper->SetScalarRange(0,1);
+
−  contMapper->SetLookupTable(lut);
+
−  contMapper->ImmediateModeRenderingOn();
+
−
+
− 
+
−  // create an actor for the contours
+
−	vtkSmartPointer<vtkActor> contActor = vtkActor::New();
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−	contActor->SetMapper(contMapper);
+
− 
+
−  // a renderer and render window
+
−	vtkSmartPointer<vtkRenderer> ren1 = vtkRenderer::New();
+
−	vtkSmartPointer<vtkRenderWindow> renWin = vtkRenderWindow::New();
+
−  if(offscreen)
+
−  {
+
−    renWin->SetOffScreenRendering(1);
+
−  }
+
−	renWin->AddRenderer(ren1);
+
−
+
−  // an interactor
+
−  vtkSmartPointer<vtkRenderWindowInteractor> iren 
+
−    = vtkRenderWindowInteractor::New();
+
−  iren->SetRenderWindow(renWin);  
+
−
+
−	// add the actors to the scene
+
−	ren1->SetBackground(0.0,0.0,0.0);
+
−  ren1->GetActiveCamera()->SetViewUp(0,0,1);
+
−  ren1->GetActiveCamera()->SetPosition(1, -1, -1);
+
−  ren1->GetActiveCamera()->SetParallelProjection(1);
+
−	ren1->AddActor(contActor);
+
−  ren1->ResetCamera();
+
− 
+
−  // render an image (lights and cameras are created automatically)
+
−	renWin->Render();
+
−
+
−  if(offscreen)
+
−  {
+
−    // Write to file
+
−    vtkSmartPointer<vtkWindowToImageFilter> windowToImageFilter = 
+
−      vtkSmartPointer<vtkWindowToImageFilter>::New();
+
−    windowToImageFilter->SetInput(renWin);
+
−    windowToImageFilter->Update();
+
− 
+
−    vtkSmartPointer<vtkPNGWriter> writer = vtkSmartPointer<vtkPNGWriter>::New();
+
−    writer->SetFileName("screenshot.png");
+
−    writer->SetInput(windowToImageFilter->GetOutput());
+
−    writer->Write();
+
−  }
+
−  else
+
−  {
+
−    //The style
+
−    vtkSmartPointer<vtkInteractorStyleTerrain> terrain_style 
+
−      = vtkInteractorStyleTerrain::New();
+
− 
+
−    // Set the style
+
−    iren -> SetInteractorStyle(terrain_style);
+
−  
+
−    // begin mouse interaction
+
−    iren->Start(); 
+
−  }
+
−}