def affine_transform_pointcloud(x, tx):
    """
    Apply the affine transform tx to the point cloud x
    :param x: A pytorch tensor of shape [N, 3]
    :param tx: An affine transformation represented as a tuple (t, s) where t is a translation and s is scale
    :return: The transformed point cloud
    """
    translate, scale = tx
    return scale * (x + translate)