Assets, Tags & Systems

Nereu uses what we call the ATS framework. It's the way you define how your assets behave in your games — and it's three letters because it's three ideas.

A — Asset. Everything in Nereu is an asset. Think of it as an object that has a name and a position in space. Internally it also carries other data that lets Nereu reference it, but that's the whole starting point: an asset just is. It renders, it sits somewhere, and it does nothing at all until you say otherwise.

T — Tags. You describe an asset's behavior using tags. Think of this as a way of telling Nereu what things are: "my character is a robot that can fly and shoot lasers." In tags, that character is [Character] [Robot] [Fly] [Shoots]. Some tags say what a thing is (a character, a robot); others say what it can do (fly, shoot). A laser would be another asset, with its own tags.

S — Systems. Systems are what give life to your assets. A System is a pre-defined piece of code, written once, that knows how to do one thing — flying, collecting, chasing, shooting. You never see or edit a System directly; a tag brings its System with it. Add [Fly] to the robot and the flying System starts handling that robot; add it to a bird and the same System — the same code, written once — handles the bird too. What keeps tags from combining into nonsense isn't the System: tags carry their own small rules ("needs", "conflicts with"), so [Fly] can refuse to sit on a [Vehicle] before any code ever runs.

That's it — that's the core idea. Assets are the things, tags are the words, and Systems are the code the words summon.

The Stash

Some things belong to your game without belonging in your level. The goblin a nest keeps making copies of. The coin a crate drops when it breaks. The bolt your blaster fires. Nereu needs one of each around to copy from — but you don't want that one standing in a corner somewhere, where a player can walk into it, pick it up, or get hurt by it.

That's what the Stash is for. Think of the item box in an old adventure game: two lists, what you're carrying and what you're keeping. A thing in the Stash has no place. It doesn't show up, nothing bumps into it, and it does none of the things its tags say it does — a stashed goblin chases nobody. Everything else about it is exactly as you left it: its name, its color, its tags and every setting on them. That's the whole point. You build the goblin once, the way you want every copy to come out, and then you put it away.

To put something away, drag its row down into the Stash fold at the bottom of the Level list, or press the box on its row, or press the box on a card in Assets to keep one you never placed. The fold opens itself the moment something lands in it. To get it back, press Place — it walks into your level and behaves like anything else.

Spawner

A spawner is a place where copies appear.

Put Spawner on whatever should be the source — a hole in a wall, a barrel, a cave mouth, or just an empty marker where you want things to turn up. Then point Spawns at your stashed goblin, by name.

Out of the box it makes one copy, one second in: that's First After 1 and Every 0 — a single arrival, then quiet. Set Every to 3 and it becomes a heartbeat, a goblin every three seconds, for as long as the game runs. Count is how many turn up per beat (they land in a small ring, so they're never stacked inside each other). Total Limit ends it for good after that many copies. Alive At Once caps the crowd — set it to 5 and the sixth waits until one of the first five is gone. Copies Face My Way points each copy the way the spawner points, which is how you send enemies down a corridor instead of off in some direction of their own.

Two neighbors, so you don't reach for a spawner when you want one of them. A spawner runs on a clock; if you want copies when something happens — a chest breaks, a boss falls — that's a Rule with a spawn action instead. And if you want to throw copies at something, that's Shoots, which aims and costs ammo. A spawner just puts things down.