Lie algebra computation

[pranavmalikk]

When i compute the vector w in the lie.py file, i consistently get a ZeroDivisionError because of this computation on line 71:

w = w_norm / (2 * sin(w_norm)) * np.array([R[2, 1] - R[1, 2], R[0, 2] - R[2, 0], R[1, 0] - R[0, 1]])

It seems like since R is an identity matrix and we are constantly returning values of 0 for all of these indices in the R array, when multiplying by 0 gives an error.

Here is my initial_params which i got from the notebook and applied the to_theta function:

initial_params = sparse_optimization.create_parameters( [0 for _ in range(n_shape_coefficients)], [0 for _ in range(n_expression_coefficients)], initial_camera_pose )

Lastly, what is SparseOptimization in the 4th notebook of 4.2.1. Setup Alternating Optimization:

face_optimizer = SparseOptimization(bfm, n_params_shape, n_params_expression, fix_camera_pose=True, weight_shape_params=weight_shape_params, weight_expression_params=weight_expression_params) camera_optimizer = SparseOptimization(bfm, 0, 0, fix_camera_pose=False)

Please let me know if i'm doing this correctly as I got this from the notebooks