How do I make edges for map territories?

[2010wolf]

Here’s an example from another game:

So my question is, how to do exactly like this. (How to replicate this with my own custom map)
What do I need to do, or what method do I need to follow?

Should I use a navmesh? maybe something else?

I’m thinking of doing something like this:
I select an origin point in the world, then spawn from it an expanding circle, and when it starts to collide with the others is when the borders stop.
Question is: how do i get data to do this?"

Though I could be very wrong…
Yeah, I’m completely blind.

[illspiritx]

In theory, you could use trigger volumes, then go into brush edit mode, extrude a few faces and drag some verts around to define the shape.