OAML is a library the makes it easy to implement adaptive music in games.
Adaptive music, also known as interactive music or dynamic music, is music that reacts to what's happening on the video game. For example, if there is a battle going on, music will get more tense to stimulate the player's reaction to the battle. There is a nice paper on the subject written by David Vink that can be found on gamecareerguide (link).
OAML uses short music loops to make music less linear and more interactive with the player.
In OAML there are three basic types of short loops:
- Intro loops, played when the track starts.
- Main loops, this is what OAML will keep playing when there is no condition triggered (actually these main loops can have one condition that is OAML_CONDID_MAIN_LOOP, check the msnake_oaml demo for more info on how it works).
- Conditional loops, these loops are defined by a condition, based on the data provided for the condition (id, type and values) OAML will play them when these conditions meet, for example, when enemies are engaged a condition can be triggered and music will play loops that get more intense.
Note that a track is only required to have one main loop at least, all the other loops are optional.
Supports the following audio formats:
- ogg
- wav
- aif
- Unity3d
- Godot: oamlGodotModule
Demos page: https://oamldev.github.io/demos/
First install libogg and libvorbis, if you don't have them already, https://www.xiph.org/downloads/.
On Linux and OSX:
mkdir build
cd build
cmake ..
make
sudo make install
On Windows with Visual Studio check the folder 'vs'.
Example of basic usage in C++:
{
// Defined somewhere in your code
oamlApi *oaml;
// Initialization, oaml.defs is the definitions saved/export with oamlStudio
oaml = new oamlApi();
oaml->Init("oaml.defs");
// Play a track
oaml->PlayTrack("track1");
// Pause music
oaml->Pause();
// Resume music
oaml->Resume();
// Stop music
oaml->StopPlaying();
// Shutdown OAML
oaml->Shutdown();
delete oaml;
}To create the oaml.defs file check oamlStudio.
When exporting music from your DAW to use with OAML the key to make the loops work seamlessly is to enable the tail on export. For now since resampling is not implemented in OAML you need to export the music in the same sample rate that your project is going to use, for example if your project uses 44100hz export all your music in 44100hz as well.
- If you're using OAML on your project or you're interested to do so and need some help contact me.
- Got any question? Write me an email to [email protected].
- Make the possibility that tension will not simply change to a condition loop but instead that both loops (main loop and conditional loop) will play together based on the tension percent, need to test it first.
- Add a function for playing SFX's with a 3d position.
- Add a loudness effect, and a reverb effect as well.
- Implement OAML in more game engines, love2d, etc.
Copyright (c) 2015-2018 Marcelo Fernandez [email protected]