AudioSource On Spline - Unity Addon

Overview

AudioSourceOnSpline is an advanced Unity component that automatically positions audio sources along splines based on player movement. This addon dynamically places audio sources at the closest point on a spline relative to the player's position, creating more realistic and immersive 3D audio experiences.

IMPORTANT: Dependencies

REQUIRED PACKAGES

This addon requires the following Unity packages to be installed in your project:

Unity Splines Package (com.unity.splines)
Version 2.0.0 or newer
Cinemachine Package (com.unity.cinemachine)
Version 2.8.0 or newer

Installation via Package Manager:

Open Window → Package Manager
Click the "+" button and select "Add package by name"
Add: com.unity.splines
Add: com.unity.cinemachine

Note: The addon will not function properly without these dependencies. Please ensure they are installed before importing AudioSourceOnSpline.

Key Features

Intelligent Positioning

Automatically finds the closest point on spline relative to player position
Uses performance-optimized algorithms for position calculation
Prioritized search around last known position for efficiency

Performance Optimization

Configurable update frequency to balance performance and responsiveness
Level-of-Detail (LOD) system - skips updates when player is far away
Minimum movement threshold prevents unnecessary calculations
Optimized search algorithms with adjustable sample counts

Smooth Movement

Optional smooth interpolation between spline positions
Configurable smoothing speed for natural audio transitions
Instant positioning mode for precise control

Highly Configurable

Easy-to-use Inspector interface with tooltips
Performance settings for different hardware capabilities
Movement and update behavior customization

Use Cases

Environmental Audio

Rivers, streams, and water sources following natural paths
Wind effects along mountain ridges or valleys
Traffic sounds following road networks

Industrial Environments

Conveyor belt systems and machinery sounds
Pipeline audio effects
Factory ambient sounds following production lines

Dynamic Music Systems

Musical elements that follow specific paths
Positional audio for concerts or performances
Interactive soundscapes

Setup Instructions

1. Prerequisites

Unity 2022.3 LTS or newer
Unity Splines package installed
Audio Source component

2. Installation

Import the AudioSourceOnSpline package into your project
Add the AudioSourceOnSpline component to any GameObject with an Audio Source
Assign required references in the Inspector

3. Basic Configuration

Spline Container: Assign the SplineContainer that defines the audio path
Player: Assign the player Transform to track
Update Frequency: Set how often position updates occur (default: 0.2 seconds)
Min Move Distance: Minimum distance player must move for updates (default: 1 unit)

Inspector Parameters

References

Spline Container: The SplineContainer component that defines the audio path
Player: The Transform of the player or camera to track

Update Settings

Update Frequency: How many times per second the position is updated (0.2 = 5 times per second)
Min Move Distance: Minimum distance the player must move before triggering an update

Movement Settings

Smooth Movement: Enable/disable smooth interpolation between positions
Smooth Speed: Speed of the smooth movement interpolation (higher = faster)

Performance Settings

Sample Count: Number of samples when searching the entire spline (lower = better performance)
Max Update Distance: Maximum distance from player before skipping updates

Performance Guidelines

Recommended Settings

High Performance (Mobile/VR):

Update Frequency: 0.3-0.5 seconds
Sample Count: 20-30
Max Update Distance: 500-1000 units

Balanced (Desktop):

Update Frequency: 0.1-0.2 seconds
Sample Count: 30-50
Max Update Distance: 1000-2000 units

High Quality (Powerful Hardware):

Update Frequency: 0.05-0.1 seconds
Sample Count: 50-100
Max Update Distance: 2000+ units

Best Practices

Optimization Tips

Use appropriate update frequencies for your use case
Set reasonable max update distances to avoid unnecessary calculations
Use smooth movement for natural audio transitions
Consider the complexity of your splines when setting sample counts

Audio Setup

Configure Audio Source 3D settings appropriately
Set proper distance attenuation curves
Use appropriate audio formats for your target platform
Consider using audio occlusion for realistic effects

Spline Design

Keep splines reasonably detailed but not overly complex
Use control points strategically for important audio positions
Test spline paths with different player movement patterns
Consider using multiple splines for complex audio environments

Troubleshooting

Common Issues

Audio source not moving:

Ensure Spline Container and Player are properly assigned
Check that the spline has valid control points
Verify update frequency is not too low

Performance issues:

Reduce sample count for complex splines
Increase update frequency interval
Set appropriate max update distance
Use LOD system effectively

Jerky movement:

Enable smooth movement
Adjust smooth speed value
Check update frequency settings
Ensure spline has sufficient detail

Audio cutting out:

Check Audio Source 3D settings
Verify distance attenuation curves
Ensure max update distance is appropriate
Check for audio occlusion issues

Technical Details

Algorithm Overview

The component uses a two-stage search algorithm:

Local Search: First searches around the last known position for efficiency
Global Search: Falls back to full spline search if local search is insufficient

Performance Characteristics

Memory Usage: Minimal - only stores essential state variables
CPU Usage: Optimized with configurable update frequencies and LOD system
Scalability: Supports multiple instances with independent settings

Version History

Version 1.0

Initial release
Basic spline following functionality
Performance optimization features
Configurable parameters

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Size

81 KB