Creature AI and behaviour

New in 0.2.0-dev.16, not yet seen in the game. Tested on a lab server without players: creatures find, ignore and hunt each other through the game’s own targeting with Kiln’s answers in it, and rules summon, cast and heal. Nobody has watched it in a real game yet.

A CreatureBlock has an AI (how it notices, chases, wanders and runs, and who it treats as an enemy) and a behaviour (rules on top of the game’s combat). Both run on the server, so on a game body players without Kiln watch the result.

Blocks.Define("warden", new CreatureBlock
{
    Body = Bodies.Vukah,
    AI = AIs.Vukah with
    {
        NightSight = 0.5,
        Flee = new FleeBlock { Below = 0.25, Min = 12, Max = 24, Seconds = 6 },
        Relations = new Dictionary<Faction, Relation> { [Faction.Player] = Relation.Neutral, [Faction.Scavenger] = Relation.Hostile },
    },
    Behaviour = Behaviours.VukahMelee with
    {
        Rules = [new RuleBlock { Every = 10, Chance = 0.3, When = [Is.HealthBelow(0.5), Is.SummonsBelow(2)],
                                 Do = [Act.Summon("Enemy_Vukah_Melee", 2), Act.Heal(0.1)] }],
    },
});

Below half health, every 10 seconds, 30% of the time, this warden calls two helpers and heals a little. It ignores players and hunts Scavengers. The CreatureAi sample in the Kiln repository has a feud between Vukahs and Scavengers, this warden, a caller written in JSON that summons and throws ice, and a ranger on the players’ side.

Who fights whom

The game decides by faction whether one creature fights another. Kiln lets you change that in three ways, most specific first:

Way	Applies to	Example
SenseFilter	one creature, about one creature or player	(npc, other) => !Friends.Contains(other)
Relations	one creature, about a faction	{ [Faction.Vukah] = Relation.Hostile }
Factions.Relate	every creature of a faction: the world’s table	Factions.Relate(Faction.Vukah, Faction.Scavenger, Relation.Hostile)

A relation is Hostile (fights), Friendly (on its side: helps, doesn’t fight), Neutral (ignores) or Game (the game’s own answer). A creature’s relations and filter are its own view: a Scavenger still fights a creature that is neutral to Scavengers, unless the world’s table or the Scavenger’s own block says otherwise.

• A sense filter runs on the tick thread every SenseEvery seconds (0.5 by default), for up to 256 others nearby. false makes it ignore that one until it asks again. Keep it short. One that throws is turned off for that creature. In JSON, name it ("senseFilter": "tokens") and register it in OnLoad with Blocks.SenseFilter("tokens", ...).
• Factions.Reset() gives back what your mod set in the world’s table, and it all goes when the mod unloads. Two mods on one pair: the last to set it wins.
• A fighter on the players’ side is a creature block with Faction = Faction.PlayerAlly. A villager from an NpcBlock has no combat AI to change.
• If a game update moves the game’s faction checks, Kiln leaves the game’s answers in place and says so in its log.

AI fields

An AI starts from a game creature’s tuning (AIs.Vukah, AIs.Scavenger, AIs.Heavy, AIs.Still). Each creature of the block gets its own copy of the values, so the game’s other creatures stay as they are. In blocks/*.json the same names are camelCase.

Field	What it does
Sight, SightAngle, Aggro, Leash	how far it sees by day, half its view cone, how close a seen target is engaged at once, its home zone’s radius
NightSight	share of Sight at night, 0 to 4
Hears, Hearing	reacts to noise at all; share of the game’s noise ranges
Threat	how much it draws enemies’ attention, 1 as the game has it
Roam { Min, Max, FromHome }	wanders while idle
Flee { Below, Min, Max, Seconds }	runs from a fight below a share of its health, as far and as long as said
ReturnsHome = false	never walks home after a fight
CallsForHelp, HelpRadius	calls the friends around it into its fights
Enable, Disable	the game’s feature switches (EnemyFeatures.Prowl, Circling, …)
Faction, Relations, SenseFilter, SenseEvery	its side, and its view of others (above)
Tune	any other game field by path; wins over the fields above

Rules

RuleBlock { On, Every, Cooldown, Chance, When, Do } goes into the game’s own rule list, so the game decides when it runs. A rule can mix the game’s conditions and actions with Kiln’s.

Kind	Conditions	Actions
The game’s own	Is.HealthBelow, Is.TargetWithin, Is.InCombat, Is.InState, Is.HasTarget, Is.TargetIsPlayer, Is.TargetHealthBelow, Is.HitWithin, Is.Chance, Is.TargetAtHome	Act.Flee, Act.BackOff, Act.Play, Act.Immune, Act.Pause, Act.EnableFeature, Act.DisableFeature, Act.SetPhase, Act.Attack
Kiln’s, reading the world	Is.EnemiesNear(count, metres), Is.AlliesNear(count, metres), Is.SummonsBelow(n)
Kiln’s, changing the world		Act.Summon, Act.Cast, Act.Heal, Act.Apply, Act.Effect, Act.Custom

• Summon puts a creature block, a variant or a game creature around it, on its side and after its target. seconds removes them after that long.
• Cast fires a delivery, such as a projectile, from where it stands at its target, without an animation. For a cast with an animation, give the creature an attack with that delivery and use Act.Attack.
• Heal takes a share of its health (Act.Heal(0.1)); Apply puts a status on it or its target.

Kiln’s conditions are checked every half second on the tick thread. Its actions run on the tick thread in the next step. JSON takes the same: { "summonsBelow": 2 }, { "summon": { "creature": "imp", "count": 2 } }, { "cast": { "type": "projectile", "speed": 25, "onHit": [ ... ] } }, { "heal": 0.1 }, { "flee": true }.

Limits

So summons can’t run away:

What	At most
Living or pending summons	16 per creature, 128 per mod, 256 in all
Summon generations	3 (a summon may call helpers, theirs may too, and that’s it)
Queued actions	4 per creature, 64 per tick; more are dropped
A summon’s radius and lifetime	200 m, one day

These hold even without an Is.SummonsBelow condition. Use Every and Cooldown for pacing.

Mistakes

Refused with the block and the field: block creature warden, ai.flee.below: 2 is outside 0..1, behaviour.rules[0].do[0].summon: count 99 is outside 1..16. kiln lint checks the AI and rules against the schema.