Only update AI path on failure. Don't tick

Hey guys,

I am building an agent based crowd simulation. I have a dynamic navmesh that updates when I place an obstacle in my building to block a path. I want my agents to only update their path when they reach the obstacle and can’t finish, instead of updating the paths of all agents the moment it is placed.

Someone know how to go about this?
Ideally I would like to stop path ticking completely and manually call a tick on each agent that gets near an obstacle. That would be perfect.

ANY kind of advice is aprecciated!

Thanks, Rodney

bump : )