x = [-2.000000; -1.000000; 2.500000; 0.000000; 5.500000; 4.500000; 3.000000]
 y = [2.500000; 5.000000; 3.500000; -2.000000; 0.500000; 6.000000; 4.500000]
 z = [1.000000; -4.500000; -3.500000; 0.000000; 2.000000; 2.500000; 0.000000]
 tri = [1 2 3; 2 3 7; 3 6 7; 3 5 6; 3 4 5; 1 3 4]
 trimesh(tri, x, y, z);