UdonStatic

Experimental UdonSharp compiler extension for static fields backed by one scene-wide global store.

Udon does not expose native C# static memory. This package emulates static field storage by creating exactly one __UdonStaticGlobalStore object in the scene and lowering static field access to typed Data arrays on that store.

Installation

Install through VCC/VPM.

Required VPM dependency:

• com.vrchat.worlds >= 3.9.0

Repository release tags should match package.json version, for example 0.1.0 or v0.1.0.

Usage

Source:

using UdonSharp;
using UnityEngine;

public class Example : UdonSharpBehaviour
{
    private static int Counter = 10;
    private static float Elapsed;

    public int visibleCounter;
    public float visibleElapsed;

    private void Update()
    {
        Counter++;
        Elapsed += Time.deltaTime;

        visibleCounter = Counter;
        visibleElapsed = Elapsed;
    }
}

Lowered shape:

private K13A.UdonStatic.Runtime.UdonStaticGlobalStore __udonStaticStore;

private K13A.UdonStatic.Runtime.UdonStaticGlobalStore __UdonStatic_GetStore()
{
    if (__udonStaticStore == null)
        __udonStaticStore = UnityEngine.GameObject.Find("__UdonStaticGlobalStore")
            .GetComponent<K13A.UdonStatic.Runtime.UdonStaticGlobalStore>();

    return __udonStaticStore;
}

Counter becomes __UdonStatic_GetStore().IntData[index], Elapsed becomes __UdonStatic_GetStore().FloatData[index], and every instance resolves the same singleton store object.

Supported MVP:

• Direct UdonSharpBehaviour classes.
• Simple static fields declared in UdonSharp behaviour classes.
• Same-class access such as Counter++.
• Class-qualified access such as Example.Counter = 10, including from another UdonSharp behaviour compiled in the same pass.
• Field initializers for common literal values.
• One scene singleton object named __UdonStaticGlobalStore.

Data storage:

• IntData, FloatData, BoolData, StringData
• LongData, DoubleData
• Vector2Data, Vector3Data, QuaternionData, ColorData
• GameObjectData, TransformData
• ObjectData UnityEngine.Object fallback

Limitations:

• This is still emulation on top of one UdonBehaviour heap, not native CLR static memory.
• Static constructors, static methods, properties, events, generic static fields, nested classes, and advanced initialization order are not implemented.
• Complex non-literal initializers default to the type default in the generated store.
• The store is scene-local. Cross-scene persistence is outside the current scope.

Examples:

• Examples/UdonStaticCounterExample.cs: static fields shared through the global store and updated every frame.

Editor tests:

• Editor/Tests/UdonStaticLowererTests.cs: validates global store lowering, same-class access, cross-class access, local shadowing, and ignored non-UdonSharp classes.