Events

TL;DR: A WasmBehaviour receives events by defining instance methods whose names match values in the UnityEvents or GameEvents enums. Presence is detected at build time via reflection; any you don’t define are never dispatched. Six Unity events are explicitly stubbed and will not fire. Post-phase events (PostUpdate, PostLateUpdate, PostFixedUpdate) run after all Unity and CVR scripts have finished the corresponding phase.

How detection works

At CCK build, WasmBuildProcessor.ScanForUnityEvents and ScanForGameEvents iterate the UnityEvents / GameEvents enums and match by method name:

foreach (UnityEvents flag in Enum.GetValues(typeof(UnityEvents))) {
    MethodInfo method = scriptType.GetMethod(flag.ToString(),
        BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
    unityEvents = WasmEventUtils.SetEvent(unityEvents, flag, method != null);
}

Source: CVR.CCK.Wasm/CCK/Editor/WasmBuildProcessor.cs (ScanForUnityEvents, ScanForGameEvents).

Matching is by name only (known TODO in source). A public or private method with the matching name is detected. Parameter types are not checked by the scanner — if you give a wrong-shape signature, the runtime dispatcher may pass mismatched args. Stick to the exact canonical signatures listed below.

The detected-events bitmask is stored on each WasmBehaviourInfo.definedEvents, and the union of definedGameEvents across every behaviour on the content root goes on the WasmVMAnchor.definedGameEvents. At VM setup, WasmVM.InitializeEvents only subscribes to the WasmGameEvents delegates that appear in the union, and WasmRuntimeBehaviour only attaches BaseEventForwarder components (OnAnimatorIKForwarder, OnRenderImageForwarder, …) for the Unity events the behaviour actually implements. Unused events cost nothing at runtime.

Unity lifecycle events

Event	Signature	Notes
Awake	void Awake()	Before Start.
Start	void Start()	After serialized state is restored.
Update	void Update()	Every frame.
LateUpdate	void LateUpdate()	After animations.
FixedUpdate	void FixedUpdate()	Physics step. In CVR, Time.fixedDeltaTime scales with the display refresh rate (30–144 Hz) — rate varies, timestep is consistent.
OnEnable	void OnEnable()	Behaviour enabled.
OnDisable	void OnDisable()	Behaviour disabled.
OnDestroy	void OnDestroy()	Before teardown.
OnBeforeSerialize	void OnBeforeSerialize()	Before state is snapshotted.
OnAfterDeserialize	void OnAfterDeserialize()	After state is restored.

Post-phase events

Event	Signature	Description
PostUpdate	void PostUpdate()	Runs after all Unity + scene Update calls have finished.
PostLateUpdate	void PostLateUpdate()	Runs after all LateUpdate calls, including local Avatar IK and Network IK. Best place to sample a player’s final pose.
PostFixedUpdate	void PostFixedUpdate()	Runs after all FixedUpdate calls.

These events are a CVR-specific mechanism that lets a WASM script act after everyone else in a given phase. See Execution order for the scene-scoping gotcha.

Physics events

Event	Signature	Notes
OnTriggerEnter	void OnTriggerEnter(Collider other)	3D trigger. other is the entering collider.
OnTriggerStay	void OnTriggerStay(Collider other)	Every frame while inside.
OnTriggerExit	void OnTriggerExit(Collider other)
OnTriggerEnter2D	void OnTriggerEnter2D(Collider2D other)	2D variant.
OnTriggerStay2D	void OnTriggerStay2D(Collider2D other)
OnTriggerExit2D	void OnTriggerExit2D(Collider2D other)
OnCollisionEnter	void OnCollisionEnter(Collision c)	3D solid contact.
OnCollisionStay	void OnCollisionStay(Collision c)
OnCollisionExit	void OnCollisionExit(Collision c)
OnCollisionEnter2D	void OnCollisionEnter2D(Collision2D c)	2D variant.
OnCollisionStay2D	void OnCollisionStay2D(Collision2D c)
OnCollisionExit2D	void OnCollisionExit2D(Collision2D c)
OnParticleTrigger	void OnParticleTrigger()
OnParticleCollision	void OnParticleCollision(GameObject other)
OnControllerColliderHit	void OnControllerColliderHit(ControllerColliderHit hit)	Character controller.
OnJointBreak	void OnJointBreak(float breakForce)
OnJointBreak2D	void OnJointBreak2D(Joint2D brokenJoint)

Rendering events

Event	Signature
OnBecameVisible	void OnBecameVisible()
OnBecameInvisible	void OnBecameInvisible()
OnPreCull	void OnPreCull()
OnPreRender	void OnPreRender()
OnPostRender	void OnPostRender()
OnRenderObject	void OnRenderObject()
OnWillRenderObject	void OnWillRenderObject()
OnRenderImage	void OnRenderImage(RenderTexture src, RenderTexture dst)

Mouse events

Event	Signature
OnMouseEnter	void OnMouseEnter()
OnMouseOver	void OnMouseOver()
OnMouseExit	void OnMouseExit()
OnMouseDown	void OnMouseDown()
OnMouseUp	void OnMouseUp()
OnMouseUpAsButton	void OnMouseUpAsButton()
OnMouseDrag	void OnMouseDrag()

CVR is VR-first; mouse events only fire in desktop mode. For in-world interaction in both modes, use CVR Pointer / Interactable components or bound events.

Animation / audio / transform

Event	Signature
OnAnimatorMove	void OnAnimatorMove()
OnAnimatorIK	void OnAnimatorIK(int layerIndex)
OnAudioFilterRead	void OnAudioFilterRead(float[] data, int channels)
OnTransformChildrenChanged	void OnTransformChildrenChanged()
OnTransformParentChanged	void OnTransformParentChanged()

Player events (game events)

Fired for any player crossing triggers / colliding with objects inside this script’s content root. Single-argument — the event does not tell you which trigger or collider was involved. If you need that, use Unity’s OnTriggerEnter(Collider) on the specific trigger GameObject and filter for a player collider inside.

Event	Signature
OnPlayerJoined	void OnPlayerJoined(Player player)
OnPlayerLeft	void OnPlayerLeft(Player player)
OnPlayerRespawned	void OnPlayerRespawned(Player player)
OnPlayerTriggerEnter	void OnPlayerTriggerEnter(Player player)
OnPlayerTriggerStay	void OnPlayerTriggerStay(Player player)
OnPlayerTriggerExit	void OnPlayerTriggerExit(Player player)
OnPlayerCollisionEnter	void OnPlayerCollisionEnter(Player player)
OnPlayerCollisionStay	void OnPlayerCollisionStay(Player player)
OnPlayerCollisionExit	void OnPlayerCollisionExit(Player player)

Prop events

Props carry both the Prop handle and the Unity Collider / Collision — useful because a prop can enter multiple triggers in your content.

Event	Signature
OnPropSpawned	void OnPropSpawned(Prop prop)
OnPropDespawned	void OnPropDespawned(Prop prop)
OnPropTriggerEnter	void OnPropTriggerEnter(Prop prop, Collider other)
OnPropTriggerStay	void OnPropTriggerStay(Prop prop, Collider other)
OnPropTriggerExit	void OnPropTriggerExit(Prop prop, Collider other)
OnPropCollisionEnter	void OnPropCollisionEnter(Prop prop, Collision c)
OnPropCollisionStay	void OnPropCollisionStay(Prop prop, Collision c)
OnPropCollisionExit	void OnPropCollisionExit(Prop prop, Collision c)

Portal events

Event	Signature
OnPortalCreated	void OnPortalCreated(Portal portal)
OnPortalDestroyed	void OnPortalDestroyed(Portal portal)

Networking / system events

Event	Signature	Notes
OnInstanceOwnerChange	void OnInstanceOwnerChange(Player newOwner)	Fires on GSInfoChanged.InstanceOwner. Dispatched via CVR_WasmBehaviour_OnInstanceOwnerChanged(behavioursPtr, count, playerHandle).
OnInputReady	void OnInputReady()	CVR input subsystem tick. Dispatched via CVR_WasmBehaviour_OnInputReady(behavioursPtr, count). The host also mirrors the current CVRInputStruct into the guest’s _inputStructPtr every tick, even if the behaviour doesn’t define this event.
OnWorldPermissionsChanged	void OnWorldPermissionsChanged()	Fires only on world VMs (gameObject.scene.buildIndex == -1). Dispatched via CVR_WorldPermissions_OnWorldPermissionsChanged(marshalStructPtr) — single argument, not the behaviour-list shape the others use. The guest-side dispatcher fans it out to every behaviour that defined the method.

OnReceiveMessage is not an auto-detected event — you subscribe explicitly:

void Start()
{
    Networking.OnReceiveMessage += HandleNetMessage;
}

void OnDestroy()
{
    Networking.OnReceiveMessage -= HandleNetMessage;
}

private void HandleNetMessage(Player sender, Span<byte> message)
{
    // parse and act
}

The host dispatches incoming payloads through the guest export CVR_Networking_OnReceiveMessage(senderHandle, msgPtr, msgLen) (WasmVM.CallOnReceiveMessage), which the shim converts into the delegate above. See Networking.

Explicitly disallowed events

Stubbed to empty in CVR.CCK.Wasm/Scripting/WasmBehaviour.cs inside #if !CVR_SCRIPTING_ENVIRONMENT so they compile in Unity but never dispatch at runtime:

• OnServerInitialized()
• OnConnectedToServer()
• OnGUI()
• OnApplicationQuit()
• OnApplicationFocus(bool)
• OnApplicationPause(bool)

Defining them has no effect. Use OnEnable / OnDisable / OnDestroy for lifecycle hooks.

Execution order

[DefaultExecutionOrder]

Unity’s built-in attribute is supported only among WasmBehaviours inside the same VM. It does not change when your scripts run relative to Unity or other CVR systems.

[DefaultExecutionOrder(-100)]
public partial class EarlyBird : WasmBehaviour
{
    void Awake() { /* runs before most other WasmBehaviours in this VM */ }
}

When multiple behaviours receive the same event (e.g. OnPlayerJoined), their execution order follows this attribute. Two behaviours without the attribute run in undefined order.

Post-phase events and additive scenes

Unity processes execution order per scene. When scenes load additively, each scene runs its full phase before the next:

World scene (active):
    FixedUpdate -> Update -> LateUpdate
Remote Avatars/Props/Portals scene (additive):
    FixedUpdate -> Update -> LateUpdate
Local Avatar + LateEventManager (DontDestroyOnLoad):
    FixedUpdate  -> fires PostFixedUpdate for all (subscription order)
    Update       -> fires PostUpdate for all
    LateUpdate   -> fires PostLateUpdate for all

This order matters when:

• You sample a player’s final pose — PostLateUpdate is the only place where local Avatar IK + Network IK have both been applied.
• You write to shared state that one of the other scenes will read next frame — use Post-phase variants.

Most scripts don’t need to think about this. If you do, read Unity’s execution order docs alongside.

Script-defined events (UI / persistent callback)

Any public method on a WasmBehaviour can be the target of a Unity UnityEvent persistent call (e.g. Button.onClick, Slider.onValueChanged). At build time the persistent call is rewritten to WasmRuntimeBehaviour.TriggerScriptEvent*(...) which fires a scripting_call_trigger_script_event* export. See Unity Events Rewiring. Supported argument types:

Type	Setter	Trigger
UnityEngine.Object	set__InternalEventObjectArg	TriggerScriptEventObject("Method")
int	set__InternalEventIntArg	TriggerScriptEventInt("Method")
float	set__InternalEventFloatArg	TriggerScriptEventFloat("Method")
string	set__InternalEventStringArg	TriggerScriptEventString("Method")
bool	set__InternalEventBoolArg	TriggerScriptEventBool("Method")

Void-signature persistent calls become TriggerScriptEvent("Method").

Source

• CVR-GameFiles/WasmScripting.Enums/UnityEvents.cs — 47-flag [Flags] long enum, one bit per Unity event.
• CVR-GameFiles/WasmScripting.Enums/GameEvents.cs — 22-flag [Flags] long enum, one bit per CVR game event.
• CVR-GameFiles/WasmScripting.Enums/ScriptEvent.cs — non-flag int enum, the values passed to scripting_call_event. Unity events occupy IDs 0–49, game events 200–221.
• CVR-GameFiles/WasmScripting/WasmRuntimeBehaviour.cs — Unity MonoBehaviour callbacks that route into the VM.
• CVR-GameFiles/WasmScripting/WasmVM.cs — InitializeEvents, per-event Call* methods, CallGlobalOnPlayerEvent, CallOnReceiveMessage, CallOnWorldPermissionsChanged.
• CVR-GameFiles/WasmScripting.Proxies/*Forwarder.cs — engine-side forwarders for the ten Unity events (OnAnimatorIK, OnAnimatorMove, OnAudioFilterRead, OnCollisionStay, OnParticleCollision, OnRenderImage, OnRenderObject, OnTriggerStay, OnWillRenderObject) that WasmRuntimeBehaviour attaches on demand.

Related

• Runtime Lifecycle — where each event export is looked up on the VM.
• Permissions — any event body can throw WasmAccessDeniedException from a binding call.
• Unity Events Rewiring — details for hooking UI widgets into script methods.
• Performance — call costs inside event bodies.