1. UDK Horizontal Music System using Kismet

    There is a need for a custom music solution when using the Unreal Development Kit. The default music system known as UTMapMusicInfo is limited and not completely functional as a complex music system. Using Kismet instead provides a strong visual scripting language with many possibilities for triggering sound.

    Horizontal and vertical arrangements are well used techniques for creating music systems for games. This article will focus specifically on a horizontal setup. We will explore the benefits of vertical arrangement in a future article.

    The best way to visualize a horizontal arrangement is to think of a single stereo track playing back in a DAW. This track can play only one file at a time, and each file has to contain the entire stereo mix intended to be heard. Each individual piece of music needs to be completely independent of the others because only one piece is heard at a time. For the purposes of a game the music needs to be able to loop endlessly, waiting for a specific player action to transition into the next piece.

    Horizontal arrangement techniques have been used since the dawn of game audio. The earliest gaming systems generated the musical score on the fly with limited number of polyphony and channels. Once music was sampled and streamed off a disc only one stream could play at a time, necessitating the use of a horizontal arrangement. A typical setup would have the music system changing according to different conditions or game states. Once a condition was met the music system would stop playing the first piece of music and move on to the next. Game states that are commonly used would be: health remaining, power-ups, time running out, ambient, action, death, winning, and losing.

    Horizontal music systems are still a very common approach to playing back music in games. Arcade games, casual games, and others with a linear style of gameplay often necessitate a horizontal setup. Mobile games are often limited by hardware restrictions and a horizontal setup can offer the best solution.

    When considering a horizontal music system it is important to determine how one piece of music will transition into the next. Transitions can happen immediately, at the end of the current musical loop, or after a certain number of beats. In addition the transitions either happen as a hard cut from one to the next or as a crossfade over time. For this example each musical transition happens immediately once the previous cue has finished. This maintains the linear nature of the music and keeps the everything on time and in sync.

    Looping music in Kismet

    In the UDK there are a couple of ways to loop a soundcue. The first is using a ‘Looping’ soundnode directly in the soundcue itself. This is best for ambient level sounds where you need a looping sound but don’t need the control of Kismet. The main problem with using ‘Looping’ node is you don’t have much control over how the file plays back dynamically in game.

    In Kismet you can set the ‘Finished’ output back to the ‘Play’ input on a PlaySound node. This triggers the soundcue to play over again once it reached the end of the file. You can then use other Gate node to stop playback. As the player triggers different events in the game it causes one Gate to close and another to open re-directing the ‘Finished’ output signal to reach the ‘Play’ input of the next PlaySound node.

    Description of project

    I am using the Racer Starter Kit (link here) provided by Epic Games to create and test my horizontal music system. It is one of their UDK Development Gems and contains everything needed to get started with a simple game project. It is a linear race course that uses a map based off of the EpicCitadel map provided with the UDK. There are a series of Touch Triggers placed throughout the race course. I used these as checkpoints and use the triggers to move the music system forward as the player drives through each one. You can use any number of checkpoints triggering the music system.

    This Horizontal music setup is not only limited to linear checkpoints or triggers. Any number of parameters or game states could drive the music system. Basically if it has an output in Kismet it can be hooked in to this system.

    Here is how the logic flows through the Horizontal music system:

    1. When player spawns in the level PlayerSpawned triggers the first PlaySound to start playing. It also sends a stop message to all other Playsounds in case they were still playing.

    2. When this first PlaySound is done playing it fires the FINISHED output.

    3. This feeds to the input of two Gates. The first defaults to open and triggers the first PlaySound again, and the second defaults to close and triggers the second PlaySound.

    4. The first Gate remains open, continually looping the first PlaySound, until the Touch Trigger is used and closes the gate preventing the first PlaySound from looping again.

    5. The second Gate is triggered to open by the Touch Trigger. This allow the first PlaySound, once finished, to trigger the second PlaySound to start playing. Thus transitioning seamlessly from once musical loop to the next.

    6. The second PlaySound is also connected to another similar chain of Gate and Triggers continuing though the musical progression as needed.

    Next time we will discuss a vertical Music System. If you have any questions contact me chris.at.engineaudio.com or post a comment below.

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  3. Top 10 Changes to the Unreal Audio System from UT3 to UDK



    10. New Sound Actor Icons


    9. Multiple Sound Slots for AmbientSounds


    8. SoundGroups are now called SoundClasses


    7. SoundClass Editor


    6. Ambient Zones


    5. Visual of Min Radius


    4. Switch from OpenAL to XAudio2


    3. Improved Distance Models


    2. Improved Low Pass Filters


    1. Content Browser


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  5. Game Audio Education: Engine Audio Creates a Course on Sound for Games at Full Sail University


    Engine Audio Logo Full Sail Logo


    We here at Engine Audio have been working tirelessly for the past couple of months on new curriculum for Full Sail University. We have developed a full course called “Advanced Interactive Audio” which discusses game audio topics ranging from sound design and technology to implementation and testing.   The students are using industry standard tools to develop their own custom sounds for a demo game. The students are taught about the structure of a game team and how to get a head start in the industry.  They are lead through the complete process of creating audio for games, from the concept and design stage to creating their own sounds for an interactive audio system.

    Asset creation is done in Pro Tools, with access to an amazing sound library, which can be used to supplement their own sounds they have recorded. The introduction to an interactive audio system and prototyping is done with the FMOD Designer.  Students learn about the basics of an interactive game audio system including 3d positioning, randomization, and real time parameters. Students also learn about preparing assets for mobile platforms using the iPhone Simulator and the FMOD Designer.  They create FMOD soundbanks specifically for the the iPhone, then test them out by manipulating them with real-time parameters and randomization.  The student are then required to implement all of the assets they have developed into a custom level using the UDK toolset provided by Epic Games.


    AIA Lecture RoomAIA Lab Room


    Material Created for the Class:

    Over 70 hours of class time in a month long series of Lectures and Labs

    Hours of instructional videos on the use of FMOD audio system and the UDK engine

    Over 100 pages of information on using and mastering the FMOD Designer and the UDK engine

    Custom UDK sound design level with environments like a cave, factory, snowstorm, and cityscape.

    An iPhone Simulator app for testing soundbanks created from the FMOD designer



    A BIG THANKS to all the great developers of the tools that we use for the class.  FMOD by Firelight Technologies is a total audio solution for games that is available freely for educational and non-commercial purposes.  It is one of the most widely used audio engines on the market and their people are a very friendly and helpful bunch.  Epic Games recently released their extremely popular Unreal Engine to the public as the Unreal Developers Kit.   It contains the same set of tools that the professionals use to make hit video games.  This gives our students the chance to stay current on the most popular tools for game audio developement.

    FMOD Logo EPIC Games Logo

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