Behavior Tree Design

2.3 Current behavior design is based on this. But the old implementation may be too unintuitive.

Before:

Logic={
Root={"Or"; "RestSequence"; "IdleSequence";};
RestSequence={"And"; "ShouldRest"; "DoRest";};
IdleSequence={"And"; "PickIdleTask"; "DoIdleTask";};
}

• This uses abit of boolean notation, "Or", "And" to cycle through the tree nodes.
• Root uses a Or logic, if RestSequence returns false, the tree continues to IdleSequence.
• In RestSeqeunce, it uses a And logic, if ShouldRest returns true, it continues to DoRest.

At a glance, the tree table is hard to read and write. Below are ideas to improve that.

Concept 1 BoolString Algebra

Using BoolStrings

Logic={
    Default="RestTree | IdleTree";
    RestTree="ShouldRest & [DoRest]";
    IdleTree="(PickIdleTask & [DoIdleTask]) | [TakeANap]";
}

or 

Logic={
Default="(ShouldRest & [DoRest]) | ((PickIdleTask & [DoIdleTask]) | [TakeANap])";
}

Nodes with [] are end nodes, once reached, they will stop the flow chain.

Start with Default, left to right. RestTree -> ShouldRest. - If ShouldRest function returns true -> [DoRest]. - If false, return to Default -> IdleTree.

IdleTree -> PickIdleTask: - if true -> [DoIdleTask] - if false -> [TakeANap]

Test if this design is flexible and coherent when used in a large scale brain map.

Bandit Behavior Test

Starting off with an simple assumption that Bandits will branch off between Alert and Idle. They are likely mutually exclusive, which should give us the default check of Alert or Idle. For Idle, some things a Bandit might do while idling: - IsHungry -> EatFood - WantToCleanGun -> CleanGun - TalkToBandits For Alert, seeking for a enemy, experience an anomaly, etc.. - IsEnemyInVision -> HasWeapon -> CanFireWeapon -> FireWeapon - IsEnemyMIA -> SearchEnemy

While writing this out, even Alert and Idle needs checks. - For bandit to be alert, it needs to know there is an enemy. - So now instead of Alert or Idle, it's more like HasEnemyData & Alert | IsSafe & Idle

What if we want a patrol mechanic? It's seems neither Alert or Idle. - Maybe a new logic tree for Duty. How about if bandit is in danger, like about to die? - A new tree for Danger. How about bandit interaction with other bandits? - Probably inside the IsSafe flow, in order for bandits to help or interact with other bandits as Help, Talk.

The flow of two NPC logic trees interacting together should probably look something like this. BanditA: IsSafe -> IsBanditNearby -> RequestBanter -> WaitForRequestAccept -> [BanterA] BanditB: IsSafe -> HasBanterRequest -> AcceptBanter -> RespondToBanter

Priority of trees: Danger > Alert > Duty > Idle

Logic = {
    Default = "DangerTree | AlertTree | DutyTree | IdleTree";

    DangerTree = "HasEnemyData & (IsLowHp & FleeTree | FightTree)";
    FleeTree = "EnemyIsInVision & (HideTree | BanditMedicTree)";
    HideTree = "HasHidingSpot & [RunToHide]";
    BanditMedicTree = "FindBanditMedic & [GoToBanditMedicForHeal]";
    FightTree = "EnemyIsInVision & FireWeaponTree | ReloadTree";
    FireWeaponTree = "CanFireWeapon & [FireAtEnemy]";
    ReloadTree = "CanReload & [ReloadWeapon]";

    AlertTree = "HasEnemyData & HuntTree | HealTree | AnomalyTree";
    HuntTree = "KnowEnemyExist & ShouldSearchForEnemy & [FindEnemy]";
    HealTree = "IsLowHp & BanditMedicTree";
    AnomalyTree = "HasAnomaly & [InvestigateAnomaly]";

    DutyTree = "IsOnDuty & PatrolTree";
    PatrolTree = "HasPatrolPath & [PatrolPath] | HasPostStand & [StandPost]";

    IdleTree = "ShouldRest & [DoRest] | HasIdleTask & [DoIdleTask]";
};

--This tree can be internally expanding into a single boolstring.
defaultBoolString = "(HasEnemyData & (IsLowHp & (EnemyIsInVision & ((HasHidingSpot & [RunToHide]) | (FindBanditMedic & [RunToBanditMedic]))) | (EnemyIsInVision & (CanFireWeapon & [FireAtEnemy]) | (CanReload & [ReloadWeapon])))) | (HasEnemyData & (KnowEnemyExist & ShouldSearchForEnemy & [FindEnemy]) | (HasAnomaly & [InvestigateAnomaly])) | (IsOnDuty & (HasPatrolPath & [PatrolPath] | HasPostStand & [StandPost])) | (ShouldRest & [DoRest] | PickIdleTask & [DoIdleTask])"

Conclusion: - Quicker to write and read(not at first glance?). - Reusable tree logic.

SurvivorCombatTree

LogicString = {
    Default = "HasEnemy & (InMeleeRange & MeleeTree | RangeTree) | [UnequipWeapon]";
    MeleeTree = "HaveMeleeAndEquip & [SwingMelee]";
    RangeTree = "HaveGunAndEquip & CanFireGun & [FireGun] | [ReloadGun]";
}