You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

154 lines
4.8 KiB

#include <test_common.h>
#include <igl/PI.h>
#include <igl/cotmatrix_entries.h>
#include <igl/edge_lengths.h>
#include <igl/EPS.h>
TEST_CASE("cotmatrix_entries: simple", "[igl]")
{
//The allowed error for this test
const double epsilon = 1e-15;
Eigen::MatrixXd V;
Eigen::MatrixXi F;
//This is a cube of dimensions 1.0x1.0x1.0
igl::read_triangle_mesh(test_common::data_path("cube.obj"), V, F);
//Prepare another mesh with triangles along side diagonals of the cube
//These triangles are form a regular tetrahedron of side sqrt(2)
Eigen::MatrixXi F_tet(4,3);
F_tet << 4,6,1,
6,4,3,
4,1,3,
1,6,3;
//1. Check cotmatrix_entries
Eigen::MatrixXd C1;
igl::cotmatrix_entries(V,F,C1);
REQUIRE (C1.rows() == F.rows());
REQUIRE (C1.cols() == 3);
//All angles in unit cube measure 45 or 90 degrees
//Their (half)cotangent must value 0.5 or 0.0
for(int f = 0;f<C1.rows();f++)
{
#ifdef IGL_EDGE_LENGTHS_SQUARED_H
//Hard assert if we have edge_length_squared
for(int v = 0;v<3;v++)
if (C1(f,v) > 0.1)
REQUIRE (C1(f,v) == 0.5);
else
REQUIRE (C1(f,v) == 0.0);
//All cotangents sum 1.0 for those triangles
REQUIRE (C1.row(f).sum() == 1.0);
#else
//Soft assert if we have not edge_length_squared
for(int v = 0;v<3;v++)
if (C1(f,v) > 0.1)
REQUIRE (C1(f,v) == Approx (0.5).margin( epsilon));
else
REQUIRE (C1(f,v) == Approx (0.0).margin( epsilon));
//All cotangents sum 1.0 for those triangles
REQUIRE (C1.row(f).sum() == Approx (1.0).margin( epsilon));
#endif
}
//Check the regular tetrahedron
Eigen::MatrixXd C2;
igl::cotmatrix_entries(V,F_tet,C2);
REQUIRE (C2.rows() == F_tet.rows());
REQUIRE (C2.cols() == 3);
for(int f = 0;f<C2.rows();f++)
{
//Their (half)cotangent must value 0.5 / tan(igl::PI / 3.0)
for(int v = 0;v<3;v++)
REQUIRE (C2(f,v) == Approx (0.5 / tan(igl::PI / 3.0)).margin( epsilon));
}
//Scale the cube to have huge sides
Eigen::MatrixXd V_huge = V * 1.0e8;
igl::cotmatrix_entries(V_huge,F,C1);
REQUIRE (C1.rows() == F.rows());
REQUIRE (C1.cols() == 3);
//All angles still measure 45 or 90 degrees
//Their (half)cotangent must value 0.5 or 0.0
for(int f = 0;f<C1.rows();f++)
{
#ifdef IGL_EDGE_LENGTHS_SQUARED_H
//Hard assert if we have edge_length_squared
for(int v = 0;v<3;v++)
if (C1(f,v) > 0.1)
REQUIRE (C1(f,v) == 0.5);
else
REQUIRE (C1(f,v) == 0.0);
//All cotangents sum 1.0 for those triangles
REQUIRE (C1.row(f).sum() == 1.0);
#else
//Soft assert if we have not edge_length_squared
for(int v = 0;v<3;v++)
if (C1(f,v) > 0.1)
REQUIRE (C1(f,v) == Approx (0.5).margin( epsilon));
else
REQUIRE (C1(f,v) == Approx (0.0).margin( epsilon));
//All cotangents sum 1.0 for those triangles
REQUIRE (C1.row(f).sum() == Approx (1.0).margin( epsilon));
#endif
}
//Check the huge regular tetrahedron
igl::cotmatrix_entries(V_huge,F_tet,C2);
REQUIRE (C2.rows() == F_tet.rows());
REQUIRE (C2.cols() == 3);
for(int f = 0;f<C2.rows();f++)
{
//Their (half)cotangent must value 0.5 / tan(igl::PI / 3.0)
for(int v = 0;v<3;v++)
REQUIRE (C2(f,v) == Approx (0.5 / tan(igl::PI / 3.0)).margin( epsilon));
}
//Scale the cube to have tiny sides
Eigen::MatrixXd V_tiny = V * 1.0e-8;
igl::cotmatrix_entries(V_tiny,F,C1);
REQUIRE (C1.rows() == F.rows());
REQUIRE (C1.cols() == 3);
//All angles still measure 45 or 90 degrees
//Their (half)cotangent must value 0.5 or 0.0
for(int f = 0;f<C1.rows();f++)
{
for(int v = 0;v<3;v++)
if (C1(f,v) > 0.1)
REQUIRE (C1(f,v) == Approx (0.5).margin( epsilon));
else
REQUIRE (C1(f,v) == Approx (0.0).margin( epsilon));
//All cotangents sum 1.0 for those triangles
REQUIRE (C1.row(f).sum() == Approx (1.0).margin( epsilon));
}
//Check the tiny regular tetrahedron
igl::cotmatrix_entries(V_tiny,F_tet,C2);
REQUIRE (C2.rows() == F_tet.rows());
REQUIRE (C2.cols() == 3);
for(int f = 0;f<C2.rows();f++)
{
//Their (half)cotangent must value 0.5 / tan(igl::PI / 3.0)
for(int v = 0;v<3;v++)
REQUIRE (C2(f,v) == Approx (0.5 / tan(igl::PI / 3.0)).margin( epsilon));
}
}// TEST_CASE("cotmatrix_entries: simple", "[igl]")
TEST_CASE("cotmatrix_entries: intrinsic", "[igl]")
{
Eigen::MatrixXd V;
Eigen::MatrixXi F;
//This is a cube of dimensions 1.0x1.0x1.0
igl::read_triangle_mesh(test_common::data_path("cube.obj"), V, F);
Eigen::MatrixXd Cext,Cint;
// compute C extrinsically
igl::cotmatrix_entries(V,F,Cext);
// compute C intrinsically
Eigen::MatrixXd l;
igl::edge_lengths(V,F,l);
igl::cotmatrix_entries(l,Cint);
test_common::assert_near(Cext,Cint,igl::EPS<double>());
}