Unity 5 Audio: Upgrading Unity 4 Project Audio Part 2: Snapshots and Exposed Parameters

Welcome to part 2 of

upgrading the Nightmares survival shooter project

from Unity 4 to Unity 5.

If you missed part 1 please check that out

before continuing with this video.

In this version of the Nightmares project

we have a pause menu that's been

created with the new UI system.

The pause menu is called up when you press

escape using a script called

Pause Manager, which is attached to menu canvas.

We'll look at this script in more detail

later in the video.

For more information about creating

this type of UI see the information linked below.

Before moving on to scripting we want

to do one more thing in our mixer.

We want to expose the volume

of the music group and the sound effects group

to script control so that we can set them directly

without using the snapshot system.

We'll click on the music group,

right click on the volume parameter

and choose Expose To Script.

We're also going to do this for the sound effects group.

Now in our exposed parameters list

we're going to name these two parameters.

We're going to call our first exposed parameter

musicVol

and our second

sfxVol.

To rename the parameters double click

on the parameter names.

Now that we've got the audio setup

in our project we're going to move on

to adding some scripting control.

Let's start by editing the pause manager script.

We're going to go to the menu canvas game object

and then double click on the pause manager script

to open it in mono develop.

Let's just quickly review what we have here.

We've added the name space declaration

using UnityEngine.UI

because we're using some of the functions

from the UI system including the canvas

variable type.

We're also checking if we're currently

running in the Unity editor

and if so we're adding the name space declaration

using Unity editor.

We've declared a variable of the canvas type

called Canvas, and this is the UI canvas.

In the start function we're getting a reference

to that using getComponent.

In our update function we're checking

to see if the escape key has been pressed.

If escape has been pressed

we'll flip the canvas from enabled to disabled

or visa versa.

We'll also call the pause function.

In the pause function we're setting

Time.TimeScale

We're doing this by checking if it's currently

set to 0, set it to 1

and otherwise set it to 0.

By setting Time.TimeScale to 0

we can freeze the motion of all of

the objects in our game.

We also have a public function called Quit

in which we're checking if we're using

the Unity editor we're going to do

EditorApplication.isPlaying=false

meaning it's going to stop playing the scene.

Or else we're going to call

Application.Quit

meaning if this was the build of our application

it would actually quit out to the desktop.

What we're going to do is we're going to

add some stuff to this script

to allow it to control

our audio mixer.

The first thing that we're going to add is another

name space declaration

using UnityEngine.Audio.

This is going to allow us to access

members of UnityEngine.Audio including the

audio mixer and the audio mixer snapshot classes.

We're going to add 2 public variables

of the audio mixer snapshot type.

We're going to call these Paused

and Unpaused.

These are going to correspond to the snapshots

that we created in the first video.

We're going to add a new public function under Paused.

We're going to call this function Lowpass.

In low pass we're going to check if

Time.TimeScale is currently equal to 0.

If Time.TimeScale is equal to 0

we're going to call the TransitionTo function

from the Paused snapshot.

We're going to parse in a floating point parameter

time to reach,

in this case 0.01 seconds.

If Time.TimeScale does not equal 0

we're going to call TransitionTo from

the Unpaused snapshot.

With our low pass function declared

we're now going to call it from inside

the pause function.

Let's save our script and return to Unity.

In the editor we'll see that our

pause manager script now has

2 new variables, Paused and Unpaused.

We're going to set those to our audio mixer

snapshots we created earlier using the asset picker.

We'll select the Paused snapshot

and the Unpaused snapshot.

Let's play our scene and give it a try.

Press escape and see that the paused snapshot

has been recalled, and then when we click resume

we can see that Unpaused has been recalled,

and so we can hear that it's working.

In the Paused menu

we have volume controls for the music

and for the sound effects.

We're going to use those to control our audio mixer

using scripting. Let's start by creating a new C# script

which we'll call Mix Levels.

We'll double click it to open it in mono develop.

Again the first thing we're going to start by doing

is adding the name space declaration

using UnityEngine.Audio.

Next we're going to add a public variable

of the audio mixer type called Master Mixer.

Because we won't need either the update

or the start functions we're going to delete those.

We're going to declare a public function called

SetSfxLvl.

We're going to give SetSfxLvl a

parameter of the type float

called sfxLvl.

We're going to use the sfxLvl

parameter to parse a floating point value

to master mixer and use

that to change the volume

of our sound effects level in our audio mixer.

We're going to do this using the SetFloat function.

SetFloat takes two parameters.

A string, which is the name

of the exposed parameter that we want to set.

And a floating point parameter to set the value.

We're going to parse in the string sfxVol

which is the name of the parameter that we

exposed earlier in the inspector.

We're also going to declare a second public function

called SetMusicLvl.

SetMusicLvl is also going to take

a floating point parameter, in this case called

musicLvl.

In SetMusicLvl we're also going to use SetFloat

to set the value of our exposed parameter musicVol.

Let's save our script and return to the editor.

In the editor let's add our

Mix Level script to

our menu canvas game object.

We're also going to select

our audio mixer master mixer

as the master mixer variable.

Next, in the paused panel

we're going to choose our effects

slider game object.

In the slider script you'll see that

previously onValueChanged was

changing the value of the gun barrel end

and the player audio sources directly.

Now we can reconnect those to our audio mixer.

First we're going to drag in our menu canvas.

We're going to choose from our list of functions

found on this game object

our mix level script

and we're going to choose the SetSfxLvl function

from that script.

We can remove the connection to the player audio

source by selecting it and hitting -.

We're going to do the same thing for our music slider.

Drag in our menu canvas game object.

Choose from our list of functions, in this case

mix levels, set music level.

Because we determined that -10

decibels was probably the loudest

we wanted our music to be in the mixer

we're going to set that in the max value in the slider.

We're also going to set the minimum value

to -80, which will be silent.

In the effects slider we're going to do the same thing

except it's going to be between -80

and 0.

With that setup let's play our scene

and give it a try.

We'll hit escape,

adjust the music volume,.

Let's pull down the sound effects volume too.

So there we have it.

For more information about audio mixers,

snapshots, exposed parameters and effects

see the information linked below.