Pooling#

A pool keeps inactive game objects ready to reuse and takes them back when you're done. Use pooling for repeatedly spawned objects, such as bullets, impact effects, damage numbers, and footstep decals, to reduce repeated creation and destruction.

Instantiate from Pool#

Use Instantiate from Pool to request an instance of a prefab. Set its position and rotation, then configure the pool's capacity and the instance's lifetime.

The first time it runs for a given prefab, the pool is created and filled. Later requests reuse available instances; the pool creates another if none are ready.

Setting	Controls
Prefab	The object to pool. Each prefab gets its own pool.
Capacity	How many instances to prepare up front.
Lifetime	Forever, In Game Time or In Real Time.
Duration	How long before the object returns to the pool, when the lifetime is timed.

The lifetime#

Lifetime controls whether and when the pool reclaims an object automatically.

Lifetime	Behavior
Forever	The object stays out until something returns it. The default.
In Game Time	Returns itself after Duration seconds of scaled game time.
In Real Time	Returns itself after Duration seconds of wall-clock time.

Use a timed mode for effects with a fixed lifetime, such as a muzzle flash. The pool then reclaims the object without a separate destroy after N seconds Instruction. Duration applies only to these modes; Time & tweens explains their clocks.

For a projectile that returns on impact, use Forever and return it explicitly when the collision occurs.

Choosing the capacity#

Capacity sets how many instances the pool prepares in advance. Choose it based on the number of objects that can be active at once:

• Too small and the pool grows during play, moving the allocation to a busy moment.
• Too large and the pool holds memory for objects that are never used.

Aim for the peak number that can plausibly be alive at once. For a weapon firing ten times a second with a half-second effect, five is about right; eight gives you headroom.

What pooling changes#

A pooled object retains its state between uses. Reset values that should start fresh each time the object leaves the pool.

If an object behaves differently on its second use, check which values remain from its previous use.

What to pool#

Worth pooling	Not worth pooling
Projectiles	The player
Impact and muzzle effects	Level geometry
Damage numbers and floating text	Objects created once at startup
Footstep and decal marks	Anything spawned a handful of times per session
Enemies in a wave-based game	Unique story objects

Pooling is most useful when objects are created and returned repeatedly. An object created once doesn't benefit from reuse, while still requiring pool configuration and lifecycle handling.

Referencing the object you got#

Instantiate from Pool doesn't hand you back a reference to the instance it produced, and it doesn't change Target.

Many pooled effects, such as muzzle flashes and impacts, need no follow-up reference. When an instance needs configuration, put an On Enable Event on its prefab. The Event runs whenever the object leaves the pool and receives that instance as Source.

Where to go next#

• Game Object Signals — resolve references to instantiated objects.
• Time & tweens — choose the clock used by a pool duration.
• Events — use On Enable to reset pooled objects.