I have 3D point cloud obtained from scanner. I want to obtain scanning direction from this point cloud, since I dont have it present. If I calculate average normal vector of the point cloud, I get kind of a good result, but it is not quite good solution, because normal vectors can be wrong (I dont have them, I need to calculate them for points).
So I was thinking to run PCA on my cloud. However, the resulting three eigenvectors used as direction are wrong - I have projected point cloud to the plane defined by first (and later second and third) of the three eigen vectors and median as origin. Is this supposed to work and I have some other error, or my idea of obtainign scan direction is totally wrong?