Los Santos Alive: Building a Living NPC Simulation for GTA V

Hi everyone,

Over the last few months, I've been working on a project called Los Santos Alive, and with LSPDFR integration getting closer I thought it would be interesting to share some of the thinking behind it.

One thing I want to make clear form the beginning is that Los Santos Alive didn't start as an LSPDFR project.

It started with a much bigger question:

What would GTA V look like if every NPC in the game was built around simulation first, rather than scripted interactions?

Instead of approaching the problem by asking "How do I make better traffic stops?" I asked, "How do I make NPCs feel like people that already existed before the player arrives?"

And that decision ended up shaping the entire project.

Over the past few months I've built a multitude of systems for persistent NPC state, activities, inference based destinations, dynamic behaviour transitions, world awareness, vehicle behaviour, NPC-NPC interaction, memory, contextual decision making and action execution.

The important part is that none of those systems were designed specifically for policing.

They're shared by every NPC in the world.

If two civilians are talking to each other, they're using the same architecture that later allows a suspect to respond during a traffic stop.

If somebody walks into a convenience store, grabs a drink, queues at the checkout and pays before leaving, that's all under the same behaviour system.

If somebody hears nearby gunfire, recognises a police officer, remembers what they'r'e doing, or changes behaviour because the situation escalates, those are all built on the exact same foundation.

That philosophy eventually led to what I'm calling Context 2.0

Rather than treating the world as centered around the player, this latest overhaul of the mod has completely decoupled the player from the architecture, meaning every single interaction, whether it's NPC-NPC or Player-NPC, this doesn't matter to the peds.

And for that reason, NPCs can dynamically escalate, perform actions on each other, and play out whole scenes by themselves.

This architecture is exactly what made LSPDFR integration particularly exciting to work on.

Rather than building a completely seperate "police AI" system, police interactions simply become another situation that the NPC understands.

At the basic level there will be available the entire suite of PR actions within the NPC interactions, and in addition to that, full dynamic EUP integration, that does not need configuration, and will go based off of your currently configured agencies.

Every single person in every single agency understands what agency they're in, what it's values are, what division they're in, and even they're rank, and since both NPC and player are treated as equals, a sergeant in game can boss you around if you're only a deputy.

Your AI can fully patrol for you, as you sit in the passenger seat, and it can pull over vehicles autonomously.

None of the underlying simulation had to be recoded for LSPDFR, it is simply an integration on top, and new capabilities for roleplay.

And this has probably been the biggest design goal throughout the project. Not building a specific functionality, but building real people.

LSPDFR just happens to be one of the more interesting ways to experience them.

Context 2.0 is releasing very soon, and I'm looking forward to sharing what the next stage of Los Santos Alive looks like.