Attributes

Attributes extend the functionality of your UdonSharp classes, fields, and methods. UdonSharp adds new attributes, but also supports many existing C# and Unity attributes.

tip

For a helpful overview of UdonSharp attributes, read Varneon's UdonSharp Development Practices.

UdonSharp Attributes

The following attributes are to unique to UdonSharp and the VRChat SDK.

UdonSynced

[UdonSynced] / [UdonSynced(UdonSyncMode)]

Fields with this attribute are synchronized over the network for all players in the instance. Read VRChat's networking documentation to learn more.

Example

public class Example : UdonSharpBehaviour 
{
    [UdonSynced]
    public bool synchronizedBoolean;

    [UdonSynced(UdonSyncMode.Linear)]
    // This float will be linearly interpolated
    public float synchronizedFloat;
}

UdonSyncMode

UdonSharp.UdonSyncMode

By default, [UdonSynced] fields are not interpolated. When the field changes, it changes instantly. You can change the sync mode to smoothly interpolate between the old and new value.

Name	Summary
None	No interpolation (Default)
Linear	Linear interpolation
Smooth	Smooth interpolation
NotSynced	(Default when not using [UdonSynced])

UdonBehaviourSyncMode

[UdonBehaviourSyncMode] / [UdonBehaviourSyncMode(BehaviourSyncMode)]

This attribute allows you to choose a sync mode that is applied to all instances of this UdonBehaviour. If you add this attribute, UdonSharp will hide the dropdown for choosing a sync mode in Unity. It also enabled additional validations to ensure that your synced variables are suitable for the chosen sync mode.

Example

[UdonBehaviourSyncMode(BehaviourSyncMode.Manual)]
public class Example : UdonSharpBehaviour 
{
  // This class's sync mode is manual.
}

BehaviourSyncMode

UdonSharp.BehaviourSyncMode

Use this in conjunction with UdonBehaviourSyncMode to choose a sync mode for your behaviour.

Name	Summary
Any	Nothing is enforced. You can set any sync type in Unity. (Default)
Continuous	Synced variables will be updated automatically at a very frequent rate, but may not always reliably update to save bandwidth.
Manual	Synced variables are updated manually by the user less frequently, but ensures that updates are reliable when requested.
None	Enforces no synced variables on the behaviour and hides the selection dropdown in the UI for the sync mode. Nothing is synced and SendCustomNetworkEvent will not work on the behaviour.
NoVariableSync	Enforces that there are no synced variables on the behaviour, hides the sync mode selection dropdown, and allows you to use the behaviours on GameObjects that use either Manual or Continuous sync.