Creating a volume slider

Unity Engine
1

Okay, I’ve been Googling info on how to create a volume slider for a few days now, and can’t find anything recent that I actually understand. Here’s what I attempted to do.

I’ve got a bunch of objects that play an audio clip when they are interacted with by a user or other objects. The audio clip is attached to those objects, and those objects are all tagged with the tag “Crystal”.

I created a slider, and the OnValueChanged() is connected to my GameController.AudioSlider(), which is as follows:

publicvoidAudioSlider(floatvolume)
{
foreach (GameObject crystal in GameObject.FindGameObjectsWithTag(“Crystal”)) {
crystal.GetComponent().volume = volume/100;
}
}

I get the error “The referenced script on this behavior is missing”.

So what am I doing wrong?

2

Looks like one or more of your Crystal GameObject’s don’t have an AudioSource component.

Try to narrow it down by checking for null and logging the name:

AudioSource source = crystal.GetComponent<AudioSource>();

if(source == null)
     Debug.Log("Missing AudioSource on " + crystal.name " + " GameObject");
3

That doesn’t seem to be the problem. All the Crystal objects are generated from a prefab, which is where the audio source is located. To be sure, I checked each individual crystal to verify…

4

You should be able to click on the error and have the object highlighted in the hierarchy.

This error doesn’t mean that GetComponent can’t find anything, that would give a null reference error.

This error means that one of the GameObjects in your scene has a script on it that has been deleted or renamed, and the editor can’t find the script.

For a global volume slider you can always adjust the audio listener volume instead of the source volume.

5

Ok, so I tried changing my script to the following to use the AudioListener volume instead.

public void AudioSlider(float volume)
{

Camera.main.GetComponent().volume = volume / 100;

}

And now get the error:

Assets/Scripts/GameController.cs(237,59): error CS0176: Static member `UnityEngine.AudioListener.volume’ cannot be accessed with an instance reference, qualify it with a type name instead

6

AudioListener.volume is static. So no need to use GetComponent.

AudioListener.volume = volume / 100;
7

Thank you! This works perfectly now.