def _build_binary_stl(facets):

    lines = [struct.pack(BINARY_HEADER, b'Binary STL Writer', len(facets)), ]
    for facet in facets:
        facet = list(facet)
        facet.append(0)  # need to pad the end with a unsigned short byte
        lines.append(struct.pack(BINARY_FACET, *facet))
    return lines
returns a string of binary binary data for the stl file
dataset/ETHPy150Open thearn/stl_tools/stl_tools/numpy2stl.py/_build_binary_stl