Layers

What are the different layers used for in VRChat? What special properties of some specific layers should you know?
Below I've listed the currently used (+ reserved) layers and their use cases based on experimentation using my layer inspection tools.
My layer research is currently ongoing and information on this page may still be incomplete!
Any object set to 19-21: reserved2-4 will be forced to 0: Default on build (You can still manually force the layer during runtime)
No
Name
Visual elements
Notes
0
Default
Avatar pedestals
Emojis
Default layer
1
TransparentFX
Used for Unity's Flare Assets
2
IgnoreRaycast
Ignored by Unity's Physics Raycasts if no layer mask is provided. Not ignored by VRChat's Physics Raycasts
3
reserved3
4
Water
Portals
Mirrors
5
UI
Remote camera lens
Player scanning highlight
Personal mirror visuals
Interactive objects on this layer can't be interacted with unless the menu is open
Colliders of remote players exist on this layer
6
reserved6
7
reserved7
8
Interactive
Unused by Unity and VRChat
9
Player
Remote players
Remote player chatbox
10
PlayerLocal
Local player without head
VRCMirrorReflection refuses to render this layer
11
Environment
Unused by Unity and VRChat
12
UiMenu
Nameplates
Remote camera nameplate
13
Pickup
Default pickup layer
14
PickupNoEnvironment
Personal mirror collider (regardless of whether grabbable or not)
Colliders on this layer only collide with the 'Pickup' layer
15
StereoLeft
Unused by Unity and VRChat
16
StereoRight
Unused by Unity and VRChat
17
Walkthrough
Colliders on this layer won't collide with players
18
MirrorReflection
Complete local player (shown in mirrors and cameras)
Only layer that isn't rendered by the main camera (local player's sees the headless copy of themselves on layer 10)
Colliders on this layer don't block VRChat raycasts
19
InternalUI
(Previously "reserved2")
HUD
Main menu
Camera UI
Camera lens
Cursor
Tooltips
Expression menu
Will render over everything
20
HardwareObjects
(Previously "reserved3")
21
reserved4
Changelog
[2024-09-04]
Added note about recently discovered personal mirror visuals on UI (5)
Added note about recently discovered personal mirror collider on PickupNoEnvironment (14)