1b09654530
The function direction_to_fisheye_lens_polynomial computes the inverse of fisheye_lens_polynomial_to_direction. Previously the function worked almost correctly if all parameters except k_0 and k_1 were zero (in that case it was correct except for flipping the x-axis). I replaced the fixed-point iteration (?) by Newton's method and implemented a test to make sure it works correctly with a wider range of parameter sets. Pull Request: https://projects.blender.org/blender/blender/pulls/123737