I have a quick video that shows what I have been able to do with recast and detour. The first part of the video shows a character, you all might recognize him, as he first see the player, shoots at him and then tracks him down to try and finish the job. The second part of the video is basically the same thing, however there is blue mesh on the ground. The blue mesh is the navmesh that shows where the soldier can go. The barrel in the scene, breaks up the navmesh and blocks the most direct path for the soldier to go. The soldier as a result has to take a less direct route.