I am developing a townbuilding RTS in the vein of Banished and Ancient Empires. The maps are going to be large premade islands made with the landscape tool. I’ll ignore foliage and building collision for now, as much of the gameplay will take place on a larger scale.
I want to have AI agents able to navigate around the island, but the current navmesh tool is definitely overkill. There are no caves or underpasses, so calculating navigation on a volume seems like a waste of time. All I really want is for agents to avoid steep slopes and water. So my question is: is there a system I can use where navigation is calculated with the assumption that there are no underpasses or bridges in the terrain? For example, a simple grid where each vertex is placed using ray collision tests with the terrain? And will this significantly improve mesh build times?
As another potential solution, I also wonder if “nav ribbons” could be implemented. Black and White 2 is a game with thousands of AI agents, but the navigation areas are marked by the level designer with something called a “nav ribbon”. The boundaries of the usable area are marked by vertices, like a cordon. There seems to be a similar system with the Total War series–if enough agents are pushed up against an impassible area, you can see the edges and corners of the “nav ribbon”.
If there are any other methods for achieving something similar, please post them below.