Navigation Mesh
The navigation mesh manager quickly sets up the navigation info required for police to get around your map.
The yellow box around your map outlines the area that helicopters are allowed to fly around, and should mostly enclose your map. You can adjust the box by editing the values in the inspector, or disable Automatic Helicopter Pathing completely if you know how Unity navigation works and you wish to do it manually.
Most of the time, leaving the values as-is and clicking "Generate Navigation Meshes" and then "Align Helicopter Spawns" will generate proper navigation for your map. You can check the meshes by clicking on them in the hierarchy:
The big floating one is the generated helicopter navigation mesh. Here you can see which areas the AI will be able to traverse.
Make sure the transform handles for your helicopter spawns are placed flush on the nav mesh for the helicopter:
The spawner mesh represents where the helicopter will fly in from, towards the transform handles. This doesn't have to be flush with the nav mesh:
Clicking the "Align Helicopter Spawns" button in the Nav Mesh Manager will move copter spawners down to be flush with the nav mesh automatically.