Attributes

Forms that compile (15)

Syntax	Description	Note
[UdonSynced]	Variable sync
[UdonSynced(UdonSyncMode.Linear)]	Sync with interpolation	Which kinds can be specified depends on the type.
[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	Because storage for parameters and local variables isn’t created per call.
[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 (3)

Syntax	Description	Error	Reason	Alternative
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) (without [NetworkCallable])	Calling a method with arguments over the network by name, without the attribute	TUKI0001	runtime	Add [NetworkCallable] on the receiving side
[DllImport("x")]	Calls an external library	TUKI0001	runtime	Use a method the runtime provides

The registered name of a method with parameters	Without the attribute it is registered under a name that includes the parameter types, which doesn’t match the name you wrote with nameof, so it can’t be referenced by name. Add [NetworkCallable] and it is registered under the name as written
The namespace of the sync attributes	They can be written from this language’s namespace. using the namespace you migrated from at the same time makes two attributes of the same name visible, which is a compile error (removing one of the usings makes it compile. File layout and namespaces)
The 5 not in this table	[Reactive], [Computed], [Effect], and [On] are under Reactive programming; [TsukimiTest] is under Testing

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.

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 across 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);   // => 1
    }
}

Allowing recursion

A method that calls itself needs this attribute.

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 non-public field can be assigned a value 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
    }
}

The description only appears on hover, so it isn’t in this image.

Specifying a value range

It becomes a slider in the Inspector, and values outside the given range can no longer be assigned.

using UnityEngine;
using Tsukimi;

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

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

When the Inspector is narrow, no slider appears and only the numeric field is shown. The range restriction applies just the same.

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
    }
}

The one above has the spacing. Without it, they sit flush like this.

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
    }
}