Virtual Tweens

Virtual tweens smoothly animate a value (like a float or color) over time and write the result into a variable on your UdonBehaviour. Each frame, your callback runs so you can apply the updated value however you like. Use virtual tweens when none of the built-in tween types (position, rotation, scale, etc.) cover what you need. For example, animating a score counter, a camera's field of view, or an Animator parameter.

Method	Example
TweenFloat	VRCTween.TweenFloat(0f, 100f, 2f, this, nameof(myValue), nameof(OnUpdate), VRCTweenEase.Linear)
TweenInt	VRCTween.TweenInt(0, 100, 5f, this, nameof(myValue), nameof(OnUpdate), VRCTweenEase.Linear)
TweenColor	VRCTween.TweenColor(Color.red, Color.blue, 2f, this, nameof(myValue), nameof(OnUpdate), VRCTweenEase.Linear)
TweenVector3	VRCTween.TweenVector3(Vector3.zero, Vector3.one, 2f, this, nameof(myValue), nameof(OnUpdate), VRCTweenEase.Linear)
DelayedCall	VRCTween.DelayedCall(this, nameof(OnTimer), 5f)

All methods return a VRCTweenHandle that you can use to control the tween.

TweenFloat

Animates float values:

[System.NonSerialized] public float fovValue;

VRCTweenHandle tweenHandle = VRCTween.TweenFloat(60f, 90f, 2f, this, nameof(fovValue), nameof(OnFovUpdate), VRCTweenEase.OutQuad);

public void OnFovUpdate()
{
    myCamera.fieldOfView = fovValue;  // smoothly widens the camera's field of view
}

TweenInt

Animates integer values. This is perfect for counters and scores:

[System.NonSerialized] public int scoreValue;

VRCTweenHandle tweenHandle = VRCTween.TweenInt(0, 100, 5f, this, nameof(scoreValue), nameof(OnCountUpdate), VRCTweenEase.Linear);

public void OnCountUpdate()
{
    scoreText.text = scoreValue.ToString();  // updates scoreValue smoothly as it ticks up
}

TweenColor

Animates Color values:

[System.NonSerialized] public Color lightColor;

VRCTweenHandle tweenHandle = VRCTween.TweenColor(Color.red, Color.blue, 2f, this, nameof(lightColor), nameof(OnColorUpdate), VRCTweenEase.Linear);

public void OnColorUpdate()
{
    myLight.color = lightColor;  // Value is stored in lightColor.
}

TweenVector3

Animates Vector3 values. This is useful for tweening custom positions, directions, or any three-component value as a single unit (with the easing curve applied to the vector as a whole, rather than per-axis):

[System.NonSerialized] public Vector3 targetPosition;

VRCTweenHandle tweenHandle = VRCTween.TweenVector3(Vector3.zero, new Vector3(5, 10, 0), 2f, this, nameof(targetPosition), nameof(OnPositionUpdate), VRCTweenEase.OutQuad);

public void OnPositionUpdate()
{
    // Use the interpolated value however you like.
    myParticleSystem.transform.position = targetPosition;
}

tip

Variables must be declared as public to work with virtual tweens. Use [System.NonSerialized] to prevent Unity from saving the transient tween value to your scene. You can use properly-typed variables (float, int, Color, Vector3) and run multiple tweens simultaneously by using different variable names.

DelayedCall

Creates a cancelable delayed event. This is an alternative to SendCustomEventDelayedSeconds:

VRCTweenHandle timerHandle = VRCTween.DelayedCall(this, nameof(OnTimerFinished), 5.0f);

// Cancel the timer anytime.
timerHandle.Kill();

public void OnTimerFinished()
{
    Debug.Log("5 seconds elapsed!");
}