1.Folder Ann contains the the head files to be included when using ann. More details can be found at 
http://www.cs.umd.edu/~mount/ANN/
 
2.Folder Data contains the data structures for the model and scan surfaces.

3.The IO is contained in DataContainer_IO.h and DataContainer_IO.cpp in Folder IO

4. There are two folders in Numerics. LinearAlgrebra contains basic data structures of vectors and 3d affine transformations.  MagicSoft is used for computing eigenvectors of semi-defintie positive matrices. Source codes in NR are used to perform svd. Examplec codes can be found in SO3Operations.cpp