obj reader

mesh_io.py

def read_obj(fname, max_degree=6, dtype=np.float32):
    '''
    Reads a mesh from an obj file. 
    Faces are converted into triangles.
    Arguments:
        fname: path or file-like object
        max_degree: maximum degree for the adjacency
        dtype: type for the vertex array
    Returns:
        (verts, faces)
    '''
    if isinstance(fname, str):
        fh = open(fname, 'r')
    else:
        fh = fname

    verts, faces = [], []
    
    for line in fh.readlines():
        if line == '':
            break
        line = line.strip('\n').replace('\t', ' ')
        values = line.split(' ')
        if values[0] == 'v':
            if len(values) != 4:
                raise RuntimeError('only xyz are supported')
            verts.append(list(map(float, values[1:])))
        elif values[0] == 'f':
            idxs = list(map(lambda i: int(i)-1, values[1:]))
            if len(idxs) == 3:
                faces += [idxs]
            elif len(values) == 5:
                faces += [[idxs[0], idxs[1], idxs[2]],
                          [idxs[0], idxs[2], idxs[3]]]
            else:
                raise NotImplementedError()

    if isinstance(fname, str):
        fh.close()

    return (np.array(verts, dtype=dtype),
            np.array(faces, np.int64))