koobas.hobune.stream
Change variable value based on perceived audio volume
If we know that Unity uses the calculation volume = 1.0 / (1.0 + rolloff * (distance 1.0)); to calculate volume based on distance, is it possible to use this in some way to manipulate the value of a variable based on the current 'perceived' volume? Such as changing the alpha value of a GUITexture's color.
I half-suspect the answer is a flat 'no', but if we know the rolloff value, can't we use this in some way? I guess an easier way is to fake it by checking the player's distance to the audiosource or using triggers, but that would surely mean a lot of tweaking the radius to match up with the sound rolloff. Just curious if there's another way.
Promise this will be my last question of the day!
Thanks.
[EDIT] I've been playing around with the formula to see what I can get from it, but i'll be honest and say i'm not 100% sure what i'm doing here. I couldn't get the right syntax to decalre a variable with this formula on a single line, so i've attacked it in two parts, then combined the result. The value returned is too large to be useful (ie, above 1.0) so I need a way to convert it to a value between 0 and 1 (I believe Mathf.Clamp is what i'm looking for but using Mathf.Clamp((1.0 / rolloff * dist),0.0,1.0); doesn't map it between 0.0 and 1.0). As I said, i'm fumbling around in the dark here so excuse my ignorance!
var player : GameObject; var rolloff : float;
function Start(){
// temporary, i'll assign these from the editor later audioSource = gameObject.Find("Sphere"); player = gameObject.Find("First Person Controller");
}
function Update(){
//the (distance - 1.0) part of the equation var dist = Vector3.Distance(audioSource.transform.position, player.transform.position) -1.0;
// the 1.0 + rolloff part of the equation rolloff = 1.0 + audioSource.audio.rolloffFactor;
// combining the two currentVol = 1.0 / rolloff * dist;
guiTexture.color.a = currentVol;
print(currentVol);
}
I can confirm that the above does have an effect so long as I am close to the object (ie, while currentVol is a float less than 1.0). It's constantly changing because the sphere is moving, but is definitely changing the alpha of the GUITexture as I get closer (it's actually fading out the closer I get so I might have something back to front). Still need to figure out how to map currentVol to a value between 0.0 and 1.0 however.
You're not going about this quite right anyway. The volume is NOT the "perceived volume". Humans don't hear on a linear scale. You can check out http://www.unifycommunity.com/wiki/index.php?title=Listener for something that will match better. I'd put some effort into helping you, but I think Unity 3.0 is going to make all this boring fixing of the audio curves unnecessary, so I'm waiting for that version to see what happens. Hopefully everything I put on the wiki becomes obsolete.
Hi Jessy, I know that volume is not the perceived volume, and therein lay my problem: trying to get some representation of the perceived volume which I can use to alter the value of something like a GUITexture's alpha. I found your scripts on Unify yesterday but i'll be honest, all this is over my head so I wasn't sure how I could use them to help me here. I do appreciate that it's meaningless to find an answer here since Unity 3.0 is on the way, but my project will be completed before then. However, I might just change the alpha based on distance for simplicity. Thank you for your insights.
If you know that that is the formula, nothing is stopping you from running the same formula, and doing something with the resulting value.
You can ask as many questions on a day as you like :)
Hi Lucas, i'm trying to do that but I wasn't able to combine the entire formula on a single line. I've amended my question above to show you what i've got.
