Return True if only tranlsate, rotate, and uniform scale components.

def is_affine_mat44(mat):
    """Return True if only tranlsate, rotate, and uniform scale components."""

    # Ensure scale is uniform
    if not (mat.data[0][0] == mat.data[1][1] == mat.data[2][2]):
        return False

    # Ensure row [3] is 0, 0, 0, 1
    return (mat.data[0][3] == 0 and
            mat.data[1][3] == 0 and
            mat.data[2][3] == 0 and
            mat.data[3][3] == 1)