How do you make enemies appear without the hero seeing them in the first place?

I’m building a level, and I want to have ogres appear when the hero walks to a certain area. Does anyone know how to do this?

You can add a Referee with some custom extraCode logic in it that, in the update method, every frame checks to see if the hero is close to the point, and then spawns the guys if so. Or, if you can stand to do a time-based trigger, you can just skip the Referee, add the guys, and add the DelaysExistence Component to each guy to control how long until the guy appears.