example-simplexquiver3d.cxx

Vector function on 3D simplex grid.

 
#include "vtkMath.h"
#include "vtkfigFrame.h"
#include "vtkfigScalarView.h"
#include "vtkfigVectorView.h"
#include "vtkfigTools.h"
 
inline double G(double x,double y, double z, double t) 
{
  
  return exp(-(x*x+y*y+z*z))*sin(t+x)*cos(y-t)*cos(z-2*t);
}
 
inline double dGdx(double x,double y, double z, double t) 
{
  return cos(y-t)*cos(z-2*t)*exp(-(x*x+y*y+z*z))*(cos(t+x)-2*x*sin(t+x));
}
 
inline double dGdy(double x,double y, double z, double t) 
{
  return sin(t+x)*cos(z-2*t)*exp(-(x*x+y*y+z*z))*(-2*y*cos(y-t) -sin(y-t));
}
 
inline double dGdz(double x,double y, double z, double t) 
{
  return sin(t+x)*cos(y-t)*exp(-(x*x+y*y+z*z))*(-2*z*cos(z-2*t) -sin(z-2*t));
}
 
 
int main(void)
{
  size_t nspin=vtkfig::NSpin();
  
  std::vector<double> inpoints;
  
  
  for(double x = -2; x < 2; x+=0.2)
    for(double y = -2; y < 2; y+=0.2)
      for(double z = -2; z < 2; z+=0.2)
      {
        inpoints.push_back(x + vtkMath::Random(-.1, .1));
        inpoints.push_back(y + vtkMath::Random(-.1, .1));
        inpoints.push_back(z + vtkMath::Random(-.1, .1));
      }
  
  
  
  
  
  std::vector<double>points;
  std::vector<int>cells;
  
  vtkfig::Delaunay3D(inpoints,points,cells);
  
  
  int npoints=points.size()/3;
 
  std::vector<double> u(npoints);
  std::vector<double> v(npoints);
  std::vector<double> w(npoints);
  std::vector<double>val(npoints);
  
  auto colors=vtkfig::RGBTable
    { 
      {0.0, 0.3, 0.3, 1.0},
      {0.5, 0.3, 1.0, 0.3},
      {1.0, 1.0, 0.3, 0.3}
    };
  auto qcolors=vtkfig::RGBTable
    { 
      {0.0, 0.0, 0.0, 0.0},
      {1.0, 0.0, 0.0, 0.0}
    };
  
  auto frame=vtkfig::Frame::New();
  auto dataset=vtkfig::DataSet::New();
  dataset->SetSimplexGrid(3,points,cells);
  dataset->SetPointScalar(val ,"val");
  dataset->SetPointVector(u,v,w ,"grad");
  
  auto contour=vtkfig::ScalarView::New();
  contour->SetData(dataset,"val");
  contour->SetSurfaceRGBTable(colors,255);
  contour->ShowIsolines(false);
  contour->SetValueRange(-1,1);
  
  auto quiver=vtkfig::VectorView::New();
  quiver->SetData(dataset,"grad");
  quiver->SetQuiverGrid(10,10,10);
 
  
  frame->AddFigure(contour);
  frame->AddFigure(quiver);
 
 
  
  double t=0;
  double dt=0.1;
  size_t ii=0;
  double t0=(double)clock()/(double)CLOCKS_PER_SEC;
  double i0=ii;
  while (ii<nspin)
  {
    
    for (size_t ipoint=0, ival=0;ipoint<points.size(); ipoint+=3,ival++)
    {
      val[ival]=G(points[ipoint+0],points[ipoint+1],points[ipoint+2],t);
      u[ival]=dGdx(points[ipoint+0],points[ipoint+1],points[ipoint+2],t);
      v[ival]=dGdy(points[ipoint+0],points[ipoint+1],points[ipoint+2],t);
      w[ival]=dGdz(points[ipoint+0],points[ipoint+1],points[ipoint+2],t);
    }
    dataset->SetPointScalar(val ,"val");
    dataset->SetPointVector(u,v ,w,"grad");
 
    frame->Show();
 
    if (ii==3) 
      frame->WritePNG("example-simplexquiver3d.png");
 
    t+=dt;
    double t1=(double)clock()/(double)CLOCKS_PER_SEC;
    double i1=ii;
    if (t1-t0>4.0)
    {
      printf("Frame rate: %.2f fps\n",(double)(i1-i0)/4.0);
      t0=(double)clock()/(double)CLOCKS_PER_SEC;
      i0=ii;
    }
    ii++;
  }
 
}