Regions is a city-building game we have been quietly building in Unreal Engine 5. This site is its devlog.
The idea at the core of the game is true agent-based simulation. Most city builders fake movement: traffic as statistical flow, cars spawned to look busy and deleted when inconvenient. In Regions, every vehicle is an individual agent. It has a driver with a personality — how patient they are, how small a gap they will accept, how they follow the car ahead — it perceives the traffic around it, and it decides for itself when to brake, when to merge, when to finally nose into a busy junction. A traffic jam here is not a number we display; it is thousands of small decisions piling up, the same way a real one is.
Traffic is the first system built on that spine, because roads are where a simulated city lives or dies. But the architecture underneath — lightweight entities instead of heavyweight actors — is built to carry everything that moves: buses, trams, bikes, and eventually the people themselves.
Why a devlog?
Three reasons:
- Notes to our future selves. Half of game development is re-deriving a decision you already made eight months ago. Writing it down once is cheaper.
- Working in the open keeps us honest. A system that can be explained in a few paragraphs is usually a system that actually works.
- This stuff is fun to read. We have lost entire evenings to other studios’ dev diaries about road networks and pathfinding. Time to give back.
What to expect
Expect entries about the agent simulation, roads and roundabouts, terrain and its auto-material, editor tooling, and the occasional honest write-up of a dead end. No fixed schedule — entries land when there is something worth saying.
If you want new entries as they happen, there is an RSS feed. See you in the next one.