import numpy as np
import cv2

pattern_size = (11, 8)
pattern_points = np.zeros((np.prod(pattern_size), 3), np.float32)
pattern_points[:, :2] = np.indices(pattern_size).T.reshape(-1, 2)
pattern_points *= 10

out = np.zeros((3, 4))
retval, out2, inliers= cv2.estimateAffine3D(pattern_points, pattern_points, out=out)


print((out == out2).all())