Papay-Shooter/docs/SOUND_DESIGN.md

Sound Design

Papaya Shooter's mix is stylized impact, comfortable repetition: graphic and energetic enough to match the cel-shaded action, but deliberately free of the clipped white-noise and narrow resonant tones that make a fast shooter fatiguing.

Character movement follows the same 90/10 rule as docs/CHARACTER_ART_DIRECTION.md: about 90% clean motion/thrust/body and 10% actuator, latch or servo. Mechanics explain a verb; they do not become a constant texture over the character.

Runtime mix

AudioManager owns registration, aliases, variation, routing and pooled playback. The hierarchy is:

Master (hard limiter)
├── SFX
│   ├── Weapons (light parallel compression)
│   ├── Explosions (slower body compression)
│   ├── Impacts
│   ├── Footsteps
│   ├── Movement
│   ├── Ambience
│   ├── UI
│   └── Wind
└── Music

The limiter is only a safety net for coincident shots/explosions. Assets are mastered below full scale, and category gain establishes the hierarchy before the limiter is reached.

Legacy event ids such as m4_fire, explosion, wind and ui_hover resolve to premium families in globals/audio_manager.gd. This preserves gameplay API compatibility while keeping source filenames out of weapon and UI code.

Asset construction

Run:

python tools/build_audio_assets.py
python tools/audio_audit.py

The builder is deterministic except for downloading the pinned CC0 menu track. It:

• retains the transient of the CC0 firearm recordings;
• layers a low-passed body and a short, dark reflection tail;
• reduces the abrasive 3–5 kHz region and controls peaks;
• creates four concrete, metal, wood and glass footstep variations;
• constructs a 48.5-second speed-wind master plus softened scrape, wall-run and grapple loops from recordings;
• constructs mono mechanical projectile loops for correct 3D localization;
• layers low relay/clunk UI hover/click/confirm/error/equip feedback;
• masters the CC0 menu loop to a conservative music level.

tools/audio_audit.py gates family coverage, 48 kHz format, mono/stereo intent, clipping, DC offset, headroom, loop duration, seam continuity, spectral flatness, high-frequency centroid and the explosion/firearm loudness hierarchy.

Gameplay behavior

• Footsteps raycast the actual floor collider and use its acoustic_material; brick and untagged structure map to concrete.
• Local and remote footsteps use the same surface families. Remote steps remain positional and pass through material-aware occlusion.
• Slides switch recorded friction gestures if the floor material changes and scale restrained pitch/gain with speed.
• Wall-run friction scales with speed and gets a restrained wood/metal resonance shift.
• Speed wind is a narrowed, filtered field recording and fades in above 12 m/s with a stronger velocity-pitch relationship. Its 48.5-second cycle prevents a short gust cadence from becoming audible. There is no global noise bed.
• Jump and double-jump are compact jump-jet impulses. Dash is an equally brief thrust-jet cue; clean air and low engine body dominate both.
• Grapple launch/latch/reel use distinct air, padded latch and restrained motor cues. The reel stays below the character movement and never becomes a continuous metallic foreground.
• Automatic weapon players keep eight overlapping voices; a new shot no longer cuts the previous shot's body and tail.
• Explosion pitch and gain scale with blast radius, while reflections and occlusion locate the source in the environment. Masters carry a measured body advantage over firearms and a dark industrial debris layer.
• UI hover has a short cooldown so crossing dense menus does not become a buzz. All UI feedback is built from softened relay/clunk gestures with 8 ms transient ramps and a two-pole 2.4 kHz ceiling.
• Menu music fades in and is owned by the menu scene, so it stops cleanly when a match begins.

Source and naming conventions

Licenses and download pages are recorded in assets/sounds/SOURCES.md.

• Positional one-shots and projectile loops: 48 kHz, 16-bit mono WAV.
• Player-local movement beds: 48 kHz, 16-bit stereo WAV.
• Music: 48 kHz stereo Ogg Vorbis.
• Variations: <event>_00.wav, <event>_01.wav, etc.
• Runtime event families, bus gains and pitch ranges live in AudioManager.EVENT_TUNING.