Demonstration of the point-to-plane metric for registration

Hi Developers

I have made a small demo project (overnight) demonstrating registration of vtkPolyData using the point-to-plane metric. I have made this following the VTK directory structure.

The metric requires either normals on the target or they are estimated similarly to how the vtkImplicitPolyDataDistance works. It is the most basic version of ICP point-to-plane, but the intention is that more sophisticated methods will follow, e.g. using the Gauss-Newton scheme, a bi-directional metric, priors and re-weighted least-squares.

This is a few classes that I have extracted from a much larger repository that I am working on.

The code is pretty well-documented, but it is quite far from a new remote module for VTK.

What are your thoughts
Jens Munk Hansen