Fitness definition in Documentation is wrong

[hwulfmeyer]

In https://www.open3d.org/docs/latest/tutorial/Basic/icp_registration.html
and https://www.open3d.org/docs/latest/cpp_api/classopen3d_1_1t_1_1pipelines_1_1registration_1_1_registration_result.html#a612ec06fe937ffbc94b0907365f58431

it says:

fitness, which measures the overlapping area (# of inlier correspondences / # of points in target). The higher the better.

or

For ICP: the overlapping area (# of inlier correspondences / # of points in target). Higher is better.

But that is not true. In the source code it is written as:

Open3D/cpp/open3d/pipelines/registration/Registration.cpp

Line 65 in 0333798

result.fitness_ = (double)corres_number / (double)source.points_.size();

The Documentation should be updated that the source is used and not the target, because it can lead to confusion in the interpretation of the fitness value as in our case.

Edit:
Just to mention it, here it is correct: https://www.open3d.org/docs/latest/tutorial/pipelines/icp_registration.html