Files
LBPM/tests/TestSphereCurvature.cpp
2018-09-10 20:26:43 -04:00

97 lines
2.7 KiB
C++

#include <iostream>
#include <math.h>
#include "analysis/Minkowski.h"
#include "common/Domain.h"
#include "common/SpherePack.h"
using namespace std;
/*
* Compare the measured and analytical curvature for a sphere
*
*/
int main(int argc, char **argv)
{
int i,j,k;
int Nx,Ny,Nz;
double Lx,Ly,Lz;
double fluid_isovalue=0.0;
double solid_isovalue=0.0;
Lx = Ly = Lz = 1.0;
Nx = Ny = Nz = 64;
DoubleArray Phase(Nx,Ny,Nz);
DoubleArray CubeValues(2,2,2);
printf("Set distance map \n");
for (k=0; k<Nz; k++){
for (j=0; j<Ny; j++){
for (i=0; i<Nx; i++){
Phase(i,j,k) = sqrt((1.0*i-0.5*Nx)*(1.0*i-0.5*Nx)+(1.0*j-0.5*Ny)*(1.0*j-0.5*Ny)+(1.0*k-0.5*Nz)*(1.0*k-0.5*Nz))-0.3*Nx;
}
}
}
printf("Construct local isosurface \n");
DECL sphere;
Point P1,P2,P3;
unsigned long int e1,e2,e3;
double s,s1,s2,s3;
double area = 0.f;
double Xi = 0.f;
double Vx,Vy,Vz,Wx,Wy,Wz,nx,ny,nz,norm;
for (k=0; k<Nz-1; k++){
for (j=0; j<Ny-1; j++){
for (i=0; i<Nx-1; i++){
sphere.LocalIsosurface(Phase,0.f,i,j,k);
for (unsigned long int idx=0; idx<sphere.TriangleCount; idx++){
e1 = sphere.Face(idx);
e2 = sphere.halfedge.next(e1);
e3 = sphere.halfedge.next(e2);
P1 = sphere.vertex.coords(sphere.halfedge.v1(e1));
P2 = sphere.vertex.coords(sphere.halfedge.v1(e2));
P3 = sphere.vertex.coords(sphere.halfedge.v1(e3));
// compute the area
s1 = sqrt((P1.x-P2.x)*(P1.x-P2.x)+(P1.y-P2.y)*(P1.y-P2.y)+(P1.z-P2.z)*(P1.z-P2.z));
s2 = sqrt((P1.x-P3.x)*(P1.x-P3.x)+(P1.y-P3.y)*(P1.y-P3.y)+(P1.z-P3.z)*(P1.z-P3.z));
s3 = sqrt((P2.x-P3.x)*(P2.x-P3.x)+(P2.y-P3.y)*(P2.y-P3.y)+(P2.z-P3.z)*(P2.z-P3.z));
s = 0.5*(s1+s2+s3);
area += sqrt(s*(s-s1)*(s-s2)*(s-s3));
// compute the normal vector
Vx=P2.x-P1.x;
Vy=P2.y-P1.y;
Vz=P2.z-P1.z;
Wx=P3.x-P2.x;
Wy=P3.y-P2.y;
Wz=P3.z-P2.z;
nx = Vy*Wz-Vz*Wy;
ny = Vz*Wx-Vx*Wz;
N_z = Vx*Wy-Vy*Wx;
norm = 1.f/sqrt(nx*nx+ny*ny+nz*nz);
nx *= norm;
ny *= norm;
nz *= norm;
// Euler characteristic (half edge rule: one face - 0.5*(three edges))
Xi -= 0.5;
}
// Euler characteristic -- each vertex shared by four cubes
Xi += 0.25*double(sphere.VertexCount);
}
}
}
printf("Surface area = %f (analytical = %f) \n", area,4*3.14159*0.3*0.3*double(Nx*Nx));
printf("Euler characteristic = %f (analytical = 2.0) \n",Xi);
// printf("Mean Curvature Average = %f, Analytical = %f \n", wn_curvature_sum/wn_area_sum, 2.0/rad[0]/101 );
int toReturn = 0;
/* if ( fabs(wn_curvature_sum/wn_area_sum -2.0/rad[0]/101)*rad[0]*101.0*0.5 > 0.01 ){
toReturn = 1;
printf("Mean curvature test error exceeds relative error tolerance \n ");
}
*/
return toReturn;
}