Attributes

Forms that compile (15)

Syntax	Description
[UdonSynced]	Variable sync
[UdonSynced(UdonSyncMode.Linear)]	Sync with interpolation
[UdonBehaviourSyncMode(BehaviourSyncMode.Manual)]	Specifying send timing
[UdonBehaviourSyncMode(BehaviourSyncMode.Continuous)]	Continuous sending
[FieldChangeCallback(nameof(Value))]	Change notification
[NetworkCallable]	Allowing calls over the network
[RecursiveMethod]	Allowing recursion
[Inline]	Inlining calls
[SerializeField]	Showing a private field
[HideInInspector]	Hiding a public field
[Header] [Tooltip]	Header and description
[Range(0f, 1f)]	Specifying a value range
[Space]	Spacing
[SerializeField, Range(0f, 1f)]	Multiple attributes on one field
[System.Obsolete]	Marking as obsolete

Forms that don’t compile (2)

Syntax	Description	Error	Reason	Instead
private int Down(int n) { return Down(n - 1); }	Calling itself without the attribute	TUKI0001	runtime	Add [RecursiveMethod] (or write it with a loop or your own stack)
SendCustomNetworkEvent(…, nameof(Take), 1)（[NetworkCallable] 無し）	Calling a method with arguments over the network by name, without the attribute	TUKI0001	runtime	Add [NetworkCallable] on the receiving side
Without the attribute, a method with arguments is registered under a name that includes the argument types. That doesn’t match the name written with nameof, so it can’t be looked up by name. Adding [NetworkCallable] registers it under the name as written.

The sync attributes can be written from this language’s namespace. Using the migration source namespace at the same time makes two attributes with the same name visible, which stops compilation. Removing one using fixes it (Program shape).

Sync

Variable sync

A variable with [UdonSynced] keeps the same value across players.

using UnityEngine;
using Tsukimi;

public class AttributesSynced : TsukimiBehaviour
{
    [UdonSynced] private int value;

    void Start()
    {
        value = 1;
        RequestSerialization();
        Debug.Log(value);   // => 1
    }
}

Sync with interpolation

UdonSyncMode specifies the kind of interpolation. Which kinds are available depends on the type.

using UnityEngine;
using Tsukimi;

public class AttributesSyncedInterpolated : TsukimiBehaviour
{
    [UdonSynced(UdonSyncMode.Linear)] private float value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Specifying send timing

With Manual, the value is sent when you call RequestSerialization().

using UnityEngine;
using Tsukimi;

[UdonBehaviourSyncMode(BehaviourSyncMode.Manual)]
public class AttributesSyncModeManual : TsukimiBehaviour
{
    [UdonSynced] private int value;

    void Start()
    {
        value = 1;
        RequestSerialization();
    }
}

Continuous sending

With Continuous, the value is sent without calling RequestSerialization().

using UnityEngine;
using Tsukimi;

[UdonBehaviourSyncMode(BehaviourSyncMode.Continuous)]
public class AttributesSyncModeContinuous : TsukimiBehaviour
{
    [UdonSynced] private int value;

    void Start()
    {
        value = 1;
    }
}

Change notification

When a synced value arrives, the setter of the specified property is called.

using UnityEngine;
using Tsukimi;

public class AttributesFieldChangeCallback : TsukimiBehaviour
{
    [UdonSynced, FieldChangeCallback(nameof(Value))] private int backing;

    public int Value
    {
        get { return backing; }
        set { backing = value; }
    }

    void Start()
    {
        Value = 1;
        Debug.Log(Value);   // => 1
    }
}

Calls

Allowing calls over the network

A method called over the network with arguments needs this attribute.

using UnityEngine;
using Tsukimi;
using VRC.SDK3.UdonNetworkCalling;

public class AttributesNetworkCallable : TsukimiBehaviour
{
    [NetworkCallable]
    public void Receive(int n)
    {
        Debug.Log(n);
    }

    void Start()
    {
        Debug.Log(1);
    }
}

// Output
// 1

Allowing recursion

A method that calls itself needs this attribute, because storage for arguments and local variables isn’t created fresh for each call.

using UnityEngine;
using Tsukimi;

public class AttributesRecursiveMethod : TsukimiBehaviour
{
    [RecursiveMethod]
    private int CountDown(int n)
    {
        return n <= 0 ? 0 : CountDown(n - 1);
    }

    void Start()
    {
        Debug.Log(CountDown(3));   // => 0
    }
}

Inlining calls

A method with this attribute is expanded at the call site regardless of its size.

using UnityEngine;
using Tsukimi;

public class AttributesInline : TsukimiBehaviour
{
    [Inline]
    private int Twice(int n) { return n * 2; }

    void Start()
    {
        Debug.Log(Twice(2));   // => 4
    }
}

The inspector

Showing a private field

Even a private field can have its value set from the inspector.

using UnityEngine;
using Tsukimi;

public class AttributesSerializeField : TsukimiBehaviour
{
    [SerializeField] private int value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Hiding a public field

The field stays public but no longer appears in the inspector.

using UnityEngine;
using Tsukimi;

public class AttributesHideInInspector : TsukimiBehaviour
{
    [HideInInspector] public int value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Header and description

[Header] shows a heading, and [Tooltip] shows a description on hover, in the inspector.

using UnityEngine;
using Tsukimi;

public class AttributesHeaderAndTooltip : TsukimiBehaviour
{
    [Header("Group")]
    [Tooltip("note")]
    public int value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Specifying a value range

In the inspector it becomes a slider, and values outside the specified range can’t be entered.

using UnityEngine;
using Tsukimi;

public class AttributesRange : TsukimiBehaviour
{
    [Range(0f, 1f)] public float value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Spacing

Adds spacing between items in the inspector.

using UnityEngine;
using Tsukimi;

public class AttributesSpace : TsukimiBehaviour
{
    [Space]
    public int value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Multiple attributes on one field

using UnityEngine;
using Tsukimi;

public class AttributesMultipleOnOneField : TsukimiBehaviour
{
    [SerializeField, Range(0f, 1f)] private float value;

    void Start()
    {
        Debug.Log(value);   // => 0
    }
}

Other

Marking as obsolete

Using a member with this attribute produces a warning.

using UnityEngine;
using Tsukimi;

public class AttributesObsolete : TsukimiBehaviour
{
    [System.Obsolete]
    public void Old() { }

    void Start()
    {
        Debug.Log(1);   // => 1
    }
}