Class UnityTriggerVolumeComponent
The base of every no-code scene component that reacts to an object walking into a trigger volume: it turns the 3D and 2D trigger messages into one enter and one exit call per visitor, and lets through only the visitors the author's layer and tag filter admit. A subclass decides what entering and leaving the volume does.
Namespace: Serenity.Global.Infrastructure.Components
Assembly: Serenity.UnityGlobal.Infrastructure.dll
Syntax
public abstract class UnityTriggerVolumeComponent : MonoBehaviourRemarks
The volume is the trigger collider on the same GameObject (a UnityEngine.Collider or a UnityEngine.Collider2D with Is Trigger on). Unity only sends trigger messages when one of the two objects has a Rigidbody (or a CharacterController), which a moving player or enemy normally already has.
The visitor is the object that walked in, not the collider that touched the volume: the GameObject carrying the collider's Rigidbody (or Rigidbody2D); without one, the GameObject of the CharacterController the collider belongs to (itself or a parent); without either, the collider's own GameObject. A rig with its tag and layer on the root and hitbox colliders on its children is therefore filtered on its root, and it is one visitor: it enters when its first collider enters and leaves when its last collider leaves. Hitboxes with no body of their own only reach a volume that has a Rigidbody, as a moving volume does.
A visitor destroyed or switched off inside the volume — an enemy killed, an object returned to a pool, a collider disabled — leaves it too. In 3D Unity sends no trigger exit for any of those, so while a visitor is inside the volume checks on every fixed update whether its colliders still exist, are active and are enabled, and a visitor whose last collider is gone is reported as having left. In 2D Unity sends the exit itself, at once. With nobody inside the check returns straight away, so an empty volume does no work. A collider switched back on while inside the volume counts as inside again because Unity reports a new enter for it.
Disabling or destroying the volume forgets every visitor inside it and then calls OnVolumeDeactivated(). Unity sends no new enter message when the volume is enabled again, so it starts empty until the next object walks in. Unity delivers trigger messages to a disabled component too; a disabled volume ignores objects that enter it, and never reports a leave for a visitor it has forgotten.
Constructors
UnityTriggerVolumeComponent()
Declaration
protected UnityTriggerVolumeComponent()Properties
RequiredTag
The tag an object needs to set this volume off; empty accepts any tag.
Declaration
public string RequiredTag { get; set; }Property Value
| Type | Description |
|---|---|
| string |
TriggeringLayers
The layers whose objects set this volume off.
Declaration
public LayerMask TriggeringLayers { get; set; }Property Value
| Type | Description |
|---|---|
| LayerMask |
VisitorCount
How many admitted visitors are inside the volume right now.
Declaration
public int VisitorCount { get; }Property Value
| Type | Description |
|---|---|
| int |
Methods
Admits(GameObject)
True when candidate passes the layer and tag filter.
Declaration
public bool Admits(GameObject candidate)Parameters
| Type | Name | Description |
|---|---|---|
| GameObject | candidate | The visitor that touched the volume. |
Returns
| Type | Description |
|---|---|
| bool | Whether the visitor sets this volume off. |
OnAdmittedObjectEntered(GameObject)
Called once when an admitted visitor's first collider enters the volume.
Declaration
protected abstract void OnAdmittedObjectEntered(GameObject enteringVisitor)Parameters
| Type | Name | Description |
|---|---|---|
| GameObject | enteringVisitor | The visitor that entered. |
OnAdmittedObjectExited(GameObject)
Called once when an admitted visitor's last collider leaves the volume; VisitorCount no longer counts it. A visitor that left by being destroyed arrives already destroyed. Does nothing unless overridden.
Declaration
protected virtual void OnAdmittedObjectExited(GameObject exitingVisitor)Parameters
| Type | Name | Description |
|---|---|---|
| GameObject | exitingVisitor | The visitor that left. |
OnVolumeDeactivated()
Called when the volume is disabled or destroyed, after it has forgotten every visitor inside it. Does nothing unless overridden.
Declaration
protected virtual void OnVolumeDeactivated()