Transitions

AudioTracksManager

AudioTracksManager is the GameObject component that drives state-based music transitions. Add it to a scene object and assign your starting AudioTrack. It manages a single "currently playing" track and switches between tracks when game variables change.

Inspector fields

Field	Description
Audio Track	The track that starts playing when the scene loads.
Transitions	List of Transition assets describing every possible track switch.
Multiple Tracks	Toggle on if all tracks should be pre-instantiated (no dynamic creation per switch).
Audio Tracks	(Multiple Tracks only) The full list of tracks to pre-create.

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Transition asset

A Transition ScriptableObject describes a single track switch.

Assets → Create → OCEAN → HYDRA → Transition

Field	Description
From	The track that must be playing for this transition to fire.
To	The track to switch to.
Type	When to fire: Immediate, OnBeat, OnDownBeat, OnBar.
Duration	Crossfade length in seconds.
Variable	Variable name checked by SetInt.
State	Value the variable must equal to trigger this transition.
Stingers	Optional pool of one-shot tracks. One is picked at random and plays before the switch.

Timing modes

Mode	When it fires
Immediate	Fires right away, no sync.
OnBeat	Waits for the next metronome beat.
OnDownBeat	Waits for the next bar (downbeat).
OnBar	Same as OnDownBeat.

BPM required for beat-sync

Beat and bar timing relies on the BPM set on the current AudioTrack. If BPM is 0, the transition falls back to immediate.

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Triggering transitions via variables

Call SetInt at any time to update a variable. AudioTracksManager checks whether any Transition asset matches and fires it if so.

// Somewhere in gameplay code
AudioTracksManager musicManager = FindObjectOfType<AudioTracksManager>();

// Variable "combat" reaching value 1 triggers the matching Transition
musicManager.SetInt("combat", 1);

// Leaving combat
musicManager.SetInt("combat", 0);

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Manual transitions

You can also transition programmatically without using variables or Transition assets:

// Immediate crossfade to a track (0.5s)
musicManager.TransitionTo(bossTrack, duration: 0.5f);

// On the next bar
musicManager.TransitionTo(bossTrack, Transition.Trigger.OnBar, duration: 1f);

// On the next beat
musicManager.TransitionTo(explorationTrack, Transition.Trigger.OnBeat, duration: 0.5f);

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Queued transitions

Chain transitions back-to-back. The next one fires as soon as the previous switch completes.

// Queue up an intro stinger → then loop the main theme
musicManager.QueueTransition(introTransition);
musicManager.QueueTransition(mainThemeTransition);

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Stingers

A stinger is a short one-shot track that plays during the transition — a musical punctuation mark (e.g. a fanfare, a hit, a sting). Assign one or more AudioTrack assets to the Stingers list on a Transition. HYDRA picks one at random, plays it to completion, then fires the crossfade.

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Crossfade from code (AudioManager)

For cases where you don't need an AudioTracksManager, call Crossfade directly on AudioManager. It fades out all currently playing tracks in the same group and fades in the new one.

IAudioManager audio; // injected

// Immediate crossfade
audio.Crossfade(newTrack, duration: 1f);

// Beat-synced crossfade
audio.Crossfade(newTrack, duration: 1f, timing: Transition.Trigger.OnBar);

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Auto-ducking

When an AudioGroup starts playing, HYDRA can automatically reduce the volume of other groups — for example, SFX ducking the music during a shot.

Configure ducking on the source AudioGroup asset under the Ducking foldout:

Field	Description
Victim	The group to duck.
Attenuation dB	How much to reduce (negative, e.g. -12).
Attack Time	Seconds to reach the ducked level.
Release Time	Seconds to restore the original level.

Ducking is fully automatic — it fires whenever any track in the source group starts or stops playing.

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Snapshots

Snapshots let you save and restore the entire AudioGroup volume state as a stack — useful for cutscenes that silence everything, then restore the game mix.

// Save current volumes
audio.PushSnapshot();

// ... cutscene plays, volumes change ...

// Restore previous volumes with a 0.5s fade
audio.PopSnapshot(fade: 0.5f);

Calls can be nested — each PushSnapshot pushes onto the stack, each PopSnapshot restores the top entry.