Navigation Mesh data Is there any way to get the navigation mesh data via script? I mean a list of the navigation polygons. I can't find this CD_RECAST layer or any face custom data since it's only allowed to have custom data to id  properties, right? Is there a way? 


  Faces of the result mesh object corresponds to the triangles of the detailed meshes of the Recast navigation mesh. The index of the navigation polygon the face belongs to stored in the layer CD_RECAST of the face custom data. The visualisation is implemented using Derived Mesh mechanism (blenkernel\intern\DerivedMesh.c). Miscellaneous functions defined in blenkernel\BKE_navmesh_conversion.h are used to build the derived mesh for the visualisation.


source: https://wiki.blender.org/index.php/User:Nicks/Gsoc2010/Docs
Read the navmesh attribute of the SCA_SteeringActuator.