Unity performance tips

disable AudioSource if it's too far away or can't be heard

disable Animator if not visible

on awake do not enable/disable objects, do it in editor beforehand

for procedural mesh collider - generate it on separate thread to not stall the main thread

AudioSource.PlayOneShot creates a new audio source, play it and destroy it. make your own pool solution instead

Debug.Log is very expensive, use it only for debugging

setting .name is expensive, do it only in editor

.tag == tag is expensive, use .CompareTag(tag) instead

build navmesh on separate thread (install NavMeshComponents)

sleeping rigidbody still wastes CPU. I destroy it if no player controls entity, but create it when someone gets control

Don't use CharacterController.OnControllerColliderHit(ControllerColliderHit other). It generates 80B of garbage each frame, because ControllerColliderHit is class recreated each frame. Better manuall check ground using SphereCast, which doesn't allocate anything (same as Raycast, they both are just check of distance to colliders)

Disable shadows on what is not important, or user basic shapes

Use cheap colliders. Sphere, or Box. Better avoid MeshCollider to save performance

Unity methods which return Array - always generate garbage. Carefully cache them before needed (e.g. meshRenderer.materials)

Dont change UI canvas each frame, it rerenders it

if using yield return new WaitForSeconds();, make sure to cache the Wait. It is recreated each frame (if looped), so allocated garbage

original date: '2024-03-20'

modified: '2024-09-22'