mesh_to_tet.py

# Copyright (c) 2020 NVIDIA Corporation

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"""Convert a .mesh file (fTetWild format) to .tet (IsaacGym format)."""


def convert_mesh_to_tet(mesh_file_path, tet_output_path):
    """Convert a .mesh file to a .tet file."""
    mesh_file = open(mesh_file_path, "r")
    tet_output = open(tet_output_path, "w")

    mesh_lines = list(mesh_file)
    mesh_lines = [line.strip('\n') for line in mesh_lines]
    vertices_start = mesh_lines.index('Vertices')
    num_vertices = mesh_lines[vertices_start + 1]

    vertices = mesh_lines[vertices_start + 2:vertices_start + 2
                          + int(num_vertices)]

    tetrahedra_start = mesh_lines.index('Tetrahedra')
    num_tetrahedra = mesh_lines[tetrahedra_start + 1]
    tetrahedra = mesh_lines[tetrahedra_start + 2:tetrahedra_start + 2
                            + int(num_tetrahedra)]

    print("# Vertices, # Tetrahedra:", num_vertices, num_tetrahedra)

    # Write to tet output
    tet_output.write("# Tetrahedral mesh generated using\n\n")
    tet_output.write("# " + num_vertices + " vertices\n")
    for v in vertices:
        tet_output.write("v " + v + "\n")
    tet_output.write("\n")
    tet_output.write("# " + num_tetrahedra + " tetrahedra\n")
    for t in tetrahedra:
        line = t.split(' 0')[0]
        line = line.split(" ")
        line = [str(int(k) - 1) for k in line]
        l_text = ' '.join(line)
        tet_output.write("t " + l_text + "\n")


if __name__ == "__main__":
    convert_mesh_to_tet(
        "path/to/mesh",
        "path/to/tet")