Version Control and Auto-saves

It’s good to mess around and try things, so we’d encourage you to start playing around with the game itself as soon as possible—just make sure it’s easy to get back to a working version first. Let’s start by saving your own new version of the level. That way you can always easily go back to the original.

If you find yourself working on a commercial game you’ll have to quickly get used to the idea of version control. Obviously in a multimillion-dollar business, you can’t rely on the “I think Johnny had a copy of it on his pen drive” approach to file management. Version control software such as SVN or Perforce provides a networked system for backing up and tracking changes of all the game and development data, but even if you’re working by yourself or in a small team, it is no less important to get into good habits so you don’t lose hours of work.

Looking and Moving

If you haven’t used a game editor before, simply navigating your way around is probably going to be one of the steepest learning curves.

Views

The interface is set up as a number of Panels and the whole area is drag-and-drop configurable to suit your working habits. You can select which panels are visible from the Window menu (and if you make a mess of things, you can use the Window/Layout/Reset Layout option).

Menu: This area has the File/Open, Edit, Window, and Help menus.

Toolbar: This area has Play and Build and open Blueprints and settings.

• Modes: This panel has five sub-tabs: Place, Paint, Landscape, Foliage, and Geometry. We will be mostly using Place to find Actors that we can drag and drop into our level.
• Viewport: This is where we see the game level itself.
• World Outliner: We can search this to find Actors located in the game world.
• Details: This shows us the settings for the currently selected Actor.
• Content Browser: This is where all of our game assets are viewed.

Note that each Panel has an icon, and it’s worth getting to know some of these in order to more quickly locate the Panel you are after when you have multiple panels opened as separate Tabs. You can use Ctrl + Tab to quickly switch between open tabs.

In the Viewport panel, there are a few options for changing the views that may come in handy in the future.

Try some of these now. For instance, try changing (1) to a top-down view (Alt + J). Now look at the level in wireframe mode (2) (Alt + 2). Also try changing from lit mode to unlit. This isn’t as pretty but makes the editor run a lot smoother! We’ll be spending most of our time in perspective view (Alt + G) and lit mode (Alt + 4), so return to these settings for now.

If at this point you are getting frustrated because Unreal seems to be running slowly, then look ahead to Appendix C: Testing, Troubleshooting, and Good Practice/Tips for Slow Running. The other thing you’ll want to try is muting and unmuting the Real Time Audio from the Settings/Real Time Audio menu. For now you should hear the game music, which you may want to mute again so it doesn’t drive you crazy. You’ll want to use this Real Time Audio a lot when auditioning ambient sounds.

In-game Actors: Finding and Changing Your First Sound

As you fly around the level, you’ll notice lots of icons that are not visible when you actually play the game. These are called [Actors], and you can press G to toggle their visibility in the editor. You can of course move around the level to find and select any [Actor] you’re looking for, but it’s often quicker to use the World Outliner that is usually found in the top right-hand corner of the editor window.

Go to the World Outliner now and find [AmbientSound01] either by scrolling through the list or by typing the name in the search box (this is usually quicker).

This is an [Ambient Sound], an Actor which is typically used to place sound at specific locations in the game. In this case, however, it is playing a stereo music file and so is not actually spatialized.

Double-click on [AmbientSound01] in the list or press F with it selected to focus on it. This will shift your Viewport to look at the Actor. Now look at the Details panel, and you can see the sound that’s currently attached to this Actor, {Musicloop}. Selecting a distant Actor in the Viewport and pressing F is also very useful for quickly navigating your way around.

Try selecting a different sound from the drop-down menu, {MusicLoop_Alt} for instance, and then play the game again (Alt + P). You’ve just implemented your first game audio—easy!

You can add sounds to [Ambient Sound] Actors by using this drop-down list (which lists all suitable assets in your project folder) but another method we’ll be using a lot is via the Content Browser.

Filtering Results

Looking at the Content Browser you can see the project folder structure is replicated down the left-hand side. As you select a folder, the file path is shown along the top, and you can also use this to navigate the folders.

You can search through these folders in the same way you would in your computer’s Finder/Explorer, but there are a number of utilities that you can use that will make your searching and navigation a lot faster. After selecting the parent folder Content, use the Filters drop-down menu to choose to see only the files of type: Sounds/Sound Wave. You will now see only the Sound Waves, and you will see all of them for the entire project, including any subfolders. Having made a filter selection, this becomes a button underneath the Filters menu that you can then switch on/off when required.

In the top box, you can start typing the name of a wave you are looking for (e.g. TurretShooting) and it will again filter your results by name. A combination of typing the name in the search box and filtering by type means it’s very quick to find the asset you are after.

The View Options menu in the bottom right-hand side of the Content Browser also allows you to see your assets in a list or in columns — which provides some useful additional information we’ll be looking at later.

Let’s use the Content Browser now to find a sound to swap out for the turrets in the game.

Use the Sound Wave filter and search for “Turret” to find the {TurretLoop_Alt} sound asset. Click on this to select it.

Now in the World Outliner, search for the ambient sound [Turret_01]. With this selected you can now use its Details panel to click on the arrow alongside the Sound row to assign the item you have selected in the Content Browser to this [Ambient Sound].

This idea of selecting an asset in the Content Browser and then using the arrow key to assign it to an [Actor] is a key technique in the Unreal Engine. The magnifying glass icon next to it is equally useful, as this will find and focus on the currently assigned asset in the Content Browser.

Play the game again (Play icon in the Toolbar), and you should now hear that the first turret has a new sound. (Ordinarily we might combine the Turret graphics and the Turret sound into a re-usable Blueprint—we’ll be looking at this in the next Chapter.)

There are 9 other turrets that need changing, but this need not be laborious. If you select multiple Actors at the same time, you can access and change their Details simultaneously. Use the World Outliner again to find “Turret_”, and you should see the other 9 Actors. Select them all then assign the sound using the arrow button as you did before (make sure your asset is still selected in the Content Browser).

We’ve looked at using the World Outliner to find Actors placed in our game, and the Content Browser to find assets. The rest of the sounds for this level are controlled deeper within the system of the game, so we will now plunge straight away into the wonderful world of Blueprints.

Editing

Sound and music editing takes place outside of the Unreal Engine in your preferred DAW. We’re fans of REAPER since it’s cheap (always important!) and has a number of features that are good for batch processing audio files, something particularly useful for game audio.

So you’ve got a nice sound, let’s say for traditions sake it’s a beep, and you’re about to import it into your game.

As we’ll explore in Chapter 02, a key challenge in audio for games is that your audio needs to fit onto a gaming platform’s memory or within various download restrictions. The first thing you’ll want to do is edit it nicely, since the silent parts of a sound file actually take up exactly the same amount of memory per second as the parts with sound!

Sample Rates and File Formats

Next you’ll want to consider the sample rate and bit depth of your sound. You may have recorded it at 96kHz and 32bits for the best fidelity of information when manipulating the audio, but for playback Unreal will only accept files of 16bit format, and 96kHz is unnecessary.

What about if we took it down to 22kHz—does it really make a difference? Depending on the frequency content of this file, it may indeed make a significant difference to the sound. Use your ears (and the Nyquist-Shannon theorem) to decide. In the case of our Beep, it still sounds fine. If you have amazing quality files for all your basics, you may find yourself needing to compromise on important stufflater on (especially if you’re working on a downloadable or mobile game where file size is particularly limited).

Lastly we know that this Beep will actually be played from a specific spatialized location in the game, so we don’t actually need or want a stereo file.

So we’ve made the sound more than 100 times smaller, and in-game it will sound exactly the same.

Looping

To swap out the shield sound and music for your own, you’ll need to edit these so that they loop well. Getting a nice loop can be tricky. Unless you get lucky, your initial selection from a sound will probably loop around with some kind of audible click. We’ll look in more detail at issues around looping music in Chapter 03, but for the moment we will look at some basic looping concepts.

Usually when creating a loop, you’re either after something that definitely sounds repetitive, like a mechanical or electronic sound, or you want something that sounds seamless so it doesn’t feel like a loop at all. The key to both loopy loops and invisible loops is to combine careful listening with a close look at the waveform of the sound itself. If you want a more seamless tone, then your first aim is to find a part of the file that is fairly constant. If there is too much change or any characteristic sounds are popping out, then as it loops around these will become rhythmic and predictable, giving it a looping feel that we want to avoid in this case. For both kinds of loop, you want to find a start and end point where there isn’t too much of a jump in volume—this is what causes clicks. After making your selection, it’s often a good idea to look away from the screen when previewing your loops so you can concentrate on hearing whether it feels loopy or clicky and not be distracted by the waveform view.

For your shields you might want to start with an electronic alarm sound and find a section of it to loop for when the ships shields are on.

You may get lucky and your initial selection may sound fine, in which case just trim/crop the sound and export, and you’re done! More likely you’ll find that every time it loops around you have an audible click.

This is because there’s a very sudden change in volume when it jumps from the end of the file back to the start. You can see this from the zoomed in waveforms below.

End of loop:

Start of loop:

Zero Crossings

The answer to this jump in volume is to find the nearest zero crossing points (see your DAW manual for how to do this) so that both the start and end of your loop will be on the zero line—hence no jump in volume, hence no click!

Mono files are a lot easier to loop nicely since with a stereo file you’re looking for the coincidence of the left and right channel both having a zero crossing at the same point—which is very rare and may not be at the point where you want to loop.

Fades

Simply starting and ending your loop at zero crossing points won’t always work, so another trick to try is to zoom right into the waveform and create a very short fade in at the start and short fade out at the end. Again, this helps to ease any rapid changes in volume that can cause clicks. If you experiment with different length fades, then you can often create fades that are quick enough not to be audible but still get rid of the click.

Split and Crossfade

If you’re getting nowhere with the zero crossings or short fades, then you could try the following: Find a zero crossing point around the center of your file, and split your file at this point.

Now drag the final section to be in front of the first section, and create a little overlap. In some DAWs this will automatically create a crossfade where they overlap, but in others you’ll need to do it manually. We know that our split point was at a zero crossing, and now our split point has been moved to the very start and at the very end of the file, so in theory it should loop well, and the middle section shouldn’t click, as we’ve created a crossfade to ease the transition.

Note for some platforms your loops will need to be working in sample lengths that are divisible by a given number of samples (e.g., multiples of 64 or 28). Most tools that convert the audio for the platform will handle this automatically, but if your loop is working perfectly in your editor but not in game, it may be worth investigating this with your programmer. Looping MP3s can be particularly problematic, but there are some tools to help—See the Further Reading section of the website.

Exercise 00_02: Looping

In the folder below we’ve provided you with some audio files.

• PC: C:UsersUserNameDocumentsUnreal ProjectsDemoCh00Shooter01Loops
• Mac: /Users/UserName/Documents/Unreal Projects/DemoCh00Shooter01/Loops

1. Try some of the techniques outlined above to find some nice looping sections that you can import for your own turret sounds in a moment.

Folder Structures and Naming Conventions

Before you get too carried away with adding loads of sound and music files to your project, it’s worth taking a moment to think about how you’re going to organize them. Considering that the average game contains many thousands of audio assets, a little thought and planning now will prevent problems later on.

Useful folder structures are a good start, as illustrated in the following example:

Content Browser

Game/Audio folder: