# Multi-Target Navigation & Dynamic Costs

***

## How Target Resolution Works

During each planning cycle, `AIBehavior.Plan()` calls `ComputeCost(behavior)` on every action that has `IsIncludeOnPlanning = true`. Override `ComputeCost` to call `SelectBestBinder()`, which:

1. If `_target` (the Inspector-assigned Transform) is already set — use it as-is
2. Otherwise — query `TargetBinderRegistry` for compatible binders (filtered by `TargetTag`), score each candidate, and lock the best available one

The selected binder is locked immediately (`IsAvailable = false`) so other behaviors in the same planning cycle cannot claim it. After planning, binders held by actions that were **not** selected into the final plan are released automatically.

```csharp
public override void ComputeCost(AIBehavior behavior)
{
    SelectBestBinder(); // queries TargetBinderRegistry; locks the winner

    if (Target != null)
    {
        float dist = Vector3.Distance(behavior.transform.position, Target.position);
        SetDynamicCost(_cost + dist * 0.1f); // farther = more expensive
    }
}
```

***

## Dynamic Action Costs

Override `ComputeCost()` to set context-sensitive costs before each A\* search:

| Method                       | Description                                                                                                                     |
| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| `SetDynamicCost(float)`      | Sets the dynamic cost for the next planning cycle. Clamped to ≥ 0.01.                                                           |
| `ClearDynamicCost()`         | Reverts `Cost` to the static inspector value.                                                                                   |
| `SelectBestBinder(isRandom)` | Queries `TargetBinderRegistry` for a binder matching `TargetTag`; locks the nearest (or random) one. Call from `ComputeCost()`. |

`ComputeCost()` is called by `AIBehavior.Plan()` **before** the A\* search runs. If any action cost changed since the last plan, the plan cache is automatically invalidated.

***

## Target Selection Scoring

Each binder candidate is scored using:

```
score = distance / priority
```

Lower score wins. A binder with `Priority = 2` appears twice as close as a binder at the same distance with `Priority = 1`.

***

## Automatic Resource Locking

Resource locking is fully automatic:

| Event                                           | Behaviour                                                                             |
| ----------------------------------------------- | ------------------------------------------------------------------------------------- |
| `SelectBestBinder()` finds a binder             | Binder is locked immediately (`IsAvailable = false`)                                  |
| Action completes (`PostPerform` returns `true`) | Binder is released (`IsAvailable = true`, `_target` cleared)                          |
| Action is interrupted (`OnInterrupt`)           | Binder is released automatically (base implementation)                                |
| Action was not selected into the plan           | Binder is released in Phase 3 (async result consumed) after the plan queue is applied |
| Behavior re-enables with `Reset On Enable`      | All binders on all actions are released                                               |

To override binder release behaviour, override `OnInterrupt()` and call `base.OnInterrupt()`:

```csharp
public override void OnInterrupt()
{
    base.OnInterrupt(); // releases the locked TargetBinder
    // your cleanup here
}
```

***

## Target Wait Timeout

When `TargetWaitTimeout > 0` on an action and no binder is available at plan time, the behavior holds the dequeued action and polls each frame:

```
[Action dequeued — no binder available]
        │
        ▼  (each frame)
  Retry ResolveTarget()
        │
   ┌────┴────────────────────────────┐
   │ Binder found                    │ Timeout expired
   ▼                                 ▼
Start action normally        Skip goal → try next goal
```

Set **Target Wait Timeout** to `0` (default) to fail immediately when no binder is available.


---

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