FP smooth walking on walls best solution?

Hi guys,

I'm working on a project. I made a walking on walls code based on the code explained here

http://answers.unity3d.com/questions/155907/basic-movement-walking-on-walls.html

I worked on it and the result is not bad (is more a planet gravity system but is fine). However I reached a level in the project were I want to improve this code to obtain an effect similar to this one

https://www.youtube.com/watch?v=NvKwCBlNdwI

do you guys can help me or guide me in the right direction.

Thank you.