CrZ_ProximityActivator

CrZ_ProximityActivator is a drop-in, asset-agnostic proximity switch. You put it on a GameObject with a trigger collider, and it turns things on when the local player is inside that collider and off when they leave. It has no knowledge of what it is toggling, so the same script is reused across assets without modification.

A common use is performance: an asset's scrolling UI (or Update() loop, AudioSource, ParticleSystem, Renderer, etc.) is only left enabled while a player is close enough to notice it.

[UdonBehaviourSyncMode(BehaviourSyncMode.None)]
public class CrZ_ProximityActivator : UdonSharpBehaviour

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Setup

1. Put this script on a GameObject with a Collider set to "Is Trigger". Size the collider a bit beyond the point where the target should activate, and make sure it reaches down to the floor — the position check uses the player's feet. Use a convex collider (Box / Sphere / Capsule) so the position poll works.
2. Drag anything you want toggled into Behaviours To Toggle — UdonSharp scripts (which stops their Update() / scrolling / etc.), Canvas, AudioSource, Renderer, ParticleSystem… any Behaviour-derived component. Its .enabled is flipped.
3. (Optional) Drag whole GameObjects into Game Objects To Toggle for a harder SetActive() instead of just .enabled.
4. (Optional) Wire Notify On Enter / Exit if a target script needs a custom event hook (for example, to reset its scroll position) rather than just .enabled.

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How it stays in sync

The switch is kept correct by two mechanisms working together:

• Trigger callbacks (OnPlayerTriggerEnter / OnPlayerTriggerExit) handle a player physically walking in or out of the collider — these react instantly.
• A polling loop (Poll) re-checks the local player's position every pollInterval seconds and is the source of truth. It stays correct in the cases the trigger callbacks miss: spawning already inside the collider, respawning, being teleported, and the component being disabled and re-enabled.

The poll reschedules itself through the delayed-event queue, so there is no per-frame Update() cost.

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Inspector fields

What to toggle

Field	Type	Description
behavioursToToggle	UdonBehaviour[]	Behaviour-derived components whose .enabled is flipped when the player enters / exits range.
gameObjectsToToggle	GameObject[]	Whole GameObjects toggled with SetActive(). Heavier than toggling .enabled.

Optional custom event hooks

Field	Type	Description
notifyOnEnter	UdonSharpBehaviour[]	Scripts that receive a custom event when the local player enters range.
enterEventName	string	The custom event name sent to notifyOnEnter scripts. Default: OnProximityEnter.
notifyOnExit	UdonSharpBehaviour[]	Scripts that receive a custom event when the local player exits range.
exitEventName	string	The custom event name sent to notifyOnExit scripts. Default: OnProximityExit.

Behaviour

Field	Type	Description
invert	bool	Flips the logic: targets start enabled and are disabled on enter, re-enabled on exit. Default: false.
pollInterval	float	Seconds between local-player position checks. Walking in / out is handled instantly by the trigger callbacks; this poll only backstops spawn-inside / respawn / teleport, so 0.25–0.5 is plenty. Default: 0.25.

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Methods

OnPlayerTriggerEnter

VRChat callback. Instant activation when the local player walks into the trigger: enables the configured targets (or disables them when invert is true) and fires the notifyOnEnter events. Ignored for remote players.

public override void OnPlayerTriggerEnter(VRCPlayerApi player)

Parameters:

Parameter	Type	Description
player	VRCPlayerApi	The player that entered the trigger. Ignored unless player.isLocal.

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OnPlayerTriggerExit

VRChat callback. Instant deactivation when the local player walks out of the trigger: disables the configured targets (or enables them when invert is true) and fires the notifyOnExit events. Ignored for remote players.

public override void OnPlayerTriggerExit(VRCPlayerApi player)

Parameters:

Parameter	Type	Description
player	VRCPlayerApi	The player that left the trigger. Ignored unless player.isLocal.

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Poll

The self-scheduling position check, started by Start. Reads the local player's position, tests it against the collider with Collider.ClosestPoint, applies the resulting in/out state, and reschedules itself pollInterval seconds later via SendCustomEventDelayedSeconds. This is the source of truth that keeps the switch correct across spawn-inside, respawn, teleport and re-enable. Duplicate or stacked loops collapse themselves, so it is safe to call directly to kick the loop.

public void Poll()

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RecheckNow

Optional hook for teleporter or station scripts. Forces an immediate in/out re-check instead of waiting up to pollInterval seconds. Call it with SendCustomEvent("RecheckNow") right after you move the player.

public void RecheckNow()

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Start

Caches the trigger collider, applies the initial "out of range" state, and starts the Poll loop. There is no per-frame Update.

public void Start()

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OnEnable

Resumes the Poll loop if the component was disabled and re-enabled after Start had already run.

public void OnEnable()