File size: 2,147 Bytes
5b89cb9 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | #include <test_common.h>
#include <igl/avg_edge_length.h>
#include <iostream>
TEST_CASE("avg_edge_length: cube", "[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);
//Create scaled versions of the cube
double scale = 1.0;
double huge_scale = 1.0e8;
double tiny_scale = 1.0e-8;
Eigen::MatrixXd V_huge = V * huge_scale;
Eigen::MatrixXd V_tiny = V * tiny_scale;
//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 avg_edge_length function
double side_sq = 1.0; //squared lenght of a side
double diag_sq = 2.0; //squared lenght of a diagonal
double avg;
avg = igl::avg_edge_length(V,F);
REQUIRE (avg == Approx ((12.*sqrt(side_sq) + 6.*sqrt(diag_sq))/(12.+6.)).margin( epsilon));
//Check the regular tetrahedron
avg = igl::avg_edge_length(V,F_tet);
REQUIRE (avg == Approx (sqrt(diag_sq)).margin( epsilon));
//Scale the cube to have huge sides
side_sq = huge_scale * huge_scale; //squared lenght of a side
diag_sq = 2.0 * side_sq; //squared lenght of a diagonal
avg = igl::avg_edge_length(V_huge,F);
REQUIRE (avg == Approx ((12.*sqrt(side_sq) + 6.*sqrt(diag_sq))/(12.+6.)).margin( epsilon*huge_scale));
//Check the equilateral triangles
avg = igl::avg_edge_length(V_huge,F_tet);
REQUIRE (avg == Approx (sqrt(diag_sq)).margin( epsilon*huge_scale));
//Scale the cube to have tiny sides
side_sq = tiny_scale * tiny_scale; //squared lenght of a side
diag_sq = 2.0 * side_sq; //squared lenght of a diagonal
avg = igl::avg_edge_length(V_tiny,F);
REQUIRE (avg == Approx ((12.*sqrt(side_sq) + 6.*sqrt(diag_sq))/(12.+6.)).margin( epsilon*tiny_scale));
//Check the regular tetrahedron
avg = igl::avg_edge_length(V_tiny,F_tet);
REQUIRE (avg == Approx (sqrt(diag_sq)).margin( epsilon*tiny_scale));
}
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