Manipulating Navigation Mid-Game

The Navigation can be manipulated in several ways while playing. You can set up Navigation Links to add more ways for the NPC to navigate through the level, block entire Navigation Segments or just parts of the mesh.

AIGraph Element

Using the AIGraph Element, you can enable or disable entire Navigation Segments. Link the Element to the Nav segment either by opening the Graph Unit list with the button or the M hotkey, or holding SPACEBAR and clicking on the segment.
With the Operation setting you can either allow or forbid access to the linked segments, and even forbid access only for certain AI types.

Door Blockers & NavObstacle Element

Another way to prevent the AI from reaching certain areas is with the use of Door Blockers. Instead of blocking the entire segment, door blockers block only the parts of the mesh they collide with.
They are most commonly used to block doors, hence the name, but they can be used in many other ways, for example vehicles that roll-in at a later point in the heist like SWAT trucks.
You can find door blockers by looking for them in the Spawn Menu, they are usually colored Pink. Door blockers have to be enabled and disabled using the NavObstacle Element. Link the Element to the Door Blocker either by opening the Obstacle list with the button or the M hotkey, or holding SPACEBAR and clicking on the Unit. In the Operation select “Add” to block the navigation and an additional NavObstacle Element with the “Remove” Operation to make the navigation accessible again.

Navigation Links

Navigation Links, or Navlinks for short, are Special Objective Elements with the “Navigation Link” setting enabled. They allow AI to move between 2 unconnected segments using animations. For example, make AI climb over fences, jump over gaps or through windows, or vault over objects.
To set up Navlinks, place down a regular Special Objective Element and enable the “Navigation Link” setting.
Choose an animation in the SO Action setting.
Increase the interval so the AI waits until the Navlink is free to use again without clipping into each other.
Make sure the type of NPC you want your Navlink to use is in the Access Flag list.
Lastly, the search position has to be roughly in the area the navlink connects to. There is a button to place at the end position of the currently selected animation, but it’s not 100% reliable and may require manual tweaking.