Auto LOD Generator

Automatic Level of Detail (LOD) generator and mesh simplifier for Unity.

Transform complex 3D meshes into optimized LOD groups with just a few clicks. Perfect for game developers who want to improve performance without manually creating multiple mesh versions.

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Table of Contents

• Features
• Why Use Auto LOD Generator?
• Installation
• Quick Start
• Presets
• Menu Reference
• Advanced Features
• API Usage
• Requirements
• Troubleshooting
• FAQ
• Contributing
• Changelog
• License

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Features

Core Features

• One-Click LOD Generation - Automatically create LOD groups with configurable quality levels
• Batch Processing - Process multiple objects at once for efficient workflow
• 6 Built-in Presets - Pre-configured settings for different platforms and use cases
• Customizable LOD Levels - Configure 2-6 LOD levels with individual quality settings
• Real-time Preview - See estimated vertex/triangle counts before generation

Mesh Support

• Static Meshes - Full support for MeshFilter + MeshRenderer objects
• Skinned Meshes - Full support for SkinnedMeshRenderer (animated characters)
• Save to Assets - Export generated meshes as reusable .asset files

Workflow

• Drag & Drop Support - Simply drag objects from hierarchy or project window
• Context Menu Integration - Right-click on objects for quick access
• Keyboard Shortcuts - Speed up your workflow with hotkeys (Ctrl+Alt+L / Cmd+Alt+L)
• Undo Support - Full integration with Unity's undo system
• Custom Presets - Save and load your own preset configurations

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Why Use Auto LOD Generator?

Aspect	Without LOD	With Auto LOD
Draw Calls	1 high-poly mesh always rendered	1 appropriate mesh based on distance
Memory	Full mesh in GPU memory	Smaller meshes at distance
FPS Impact	High on low-end devices	Optimized for all devices
Setup Time	Hours of manual work	Seconds with presets

Performance Example

A character with 10,000 triangles:

• LOD0 (close): 10,000 triangles - 100% quality
• LOD1 (medium): 6,500 triangles - 65% quality
• LOD2 (far): 2,000 triangles - 20% quality
• LOD3 (very far): Culled (0 triangles)

Result: Up to 80% reduction in GPU workload at distance.

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Installation

Unity Package Manager (Recommended)

1. Open Window > Package Manager
2. Click + > Add package from git URL
3. Enter:

   https://github.com/manaporkun/Automatic-LOD-Generator.git
   

The required UnityMeshSimplifier dependency is installed automatically.

Note: To install a specific version, append the tag to the URL:

https://github.com/manaporkun/Automatic-LOD-Generator.git#v2.1.1

Manual Installation

1. Download Auto-LOD-Generator.unitypackage from the Releases page
2. In Unity, go to Assets > Import Package > Custom Package
3. Select the downloaded file and import (the dependency will be installed automatically)

Development Installation

For contributing or modifying the source:

1. Clone this repository
2. In Unity Package Manager, click + > Add package from disk
3. Select the package.json at the repository root

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Quick Start

Using the Main Window

1. Open Tools > Auto LOD Generator > Open Window
2. Select a GameObject with a mesh in your scene
3. Choose a preset or customize settings
4. Click Generate LOD Group

Using Context Menu (Fastest)

1. Right-click on any mesh object in the Hierarchy
2. Select Auto LOD > Generate LOD Group

Using Keyboard Shortcuts

Shortcut	Action
Ctrl+Alt+L (Windows) / Cmd+Alt+L (Mac)	Quick Generate LOD Group

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Presets

Preset	LOD Levels	Best For
Performance	3	Maximum FPS, aggressive simplification
Balanced	4	General use, good quality/performance balance (default)
Quality	5	Visual fidelity, gradual transitions
Mobile (Low-end)	2	Budget mobile devices
Mobile (High-end)	3	Modern mobile devices
VR	4	VR applications, avoids LOD popping

Quality Factor Guide

The quality factor determines how much the mesh is simplified:

Quality	Triangle Reduction	Use Case
1.0	0% (original)	LOD0 - Always keep original
0.75	~25%	LOD1 - Close distance
0.5	~50%	LOD2 - Medium distance
0.25	~75%	LOD3 - Far distance
0.1	~90%	LOD4 - Very far distance

Custom Presets

You can save your own custom presets:

1. Open the main window
2. Go to the Presets tab
3. Configure your settings
4. Enter a name and click Save

Preset Storage Location: Custom presets are saved to Assets/Editor/AutoLODGenerator/Presets/ by default. This ensures they persist across package updates. You can change this location in the Presets tab.

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Menu Reference

Tools Menu

Menu Item	Description
Tools > Auto LOD Generator > Open Window	Main interface
Tools > Auto LOD Generator > Quick Generate LOD Group	Generate with Balanced preset
Tools > Auto LOD Generator > Quick Simplify (50%)	Create 50% simplified mesh
Tools > Auto LOD Generator > Generate with Preset > ...	Generate with specific preset

Context Menu (Right-click in Hierarchy)

Menu Item	Description
Auto LOD > Generate LOD Group	Generate LOD group
Auto LOD > Simplify Mesh (50%)	Create 50% simplified version
Auto LOD > Simplify Mesh (25%)	Create 25% simplified version
Auto LOD > Open Generator Window...	Open main window

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Advanced Features

Save Meshes to Assets

Enable Save Meshes to Assets in the Save Options section to:

• Export generated LOD meshes as .asset files
• Reuse meshes across multiple prefabs
• Reduce scene file size
• Default save location: Assets/GeneratedLODs/

Skinned Mesh Support

The plugin automatically detects and handles both static and skinned meshes:

Feature	Static Mesh	Skinned Mesh
Component	MeshFilter + MeshRenderer	SkinnedMeshRenderer
Bone Preservation	N/A	✅ Full support
Blend Shapes	N/A	✅ Preserved
Animation	N/A	✅ Works seamlessly

Custom LOD Settings

In the main window, expand Advanced Settings to customize:

• Quality Factors - Mesh quality for each LOD level (0.0 - 1.0)
• Screen Transition Heights - When each LOD level activates based on screen coverage (0.0 - 1.0)
• Culled Level - Optional level that completely hides the object at distance

Batch Processing

1. Open the main window and go to the Batch Process tab
2. Drag multiple objects or click Add from Selection
3. Configure settings
4. Enable Save Meshes to Assets if needed
5. Click Process X Objects

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API Usage

For programmatic access, use the LODGeneratorCore class:

using Plugins.AutoLODGenerator.Editor;

// Generate LOD group with default settings
var settings = new LODGeneratorSettings();
settings.ApplyPreset(LODPreset.Balanced);

var result = LODGeneratorCore.GenerateLODGroup(myGameObject, settings);

if (result.Success)
{
    Debug.Log($"Generated LOD group: {result.GeneratedLODGroup.name}");
    Debug.Log($"Original vertices: {result.OriginalVertexCount}");
}

// Generate with mesh saving
var resultWithSave = LODGeneratorCore.GenerateLODGroup(
    myGameObject,
    settings,
    saveMeshesToAssets: true,
    meshSavePath: "Assets/MyLODs");

// Simplify a single mesh
var simplifyResult = LODGeneratorCore.GenerateSimplifiedMesh(
    myGameObject,
    quality: 0.5f,
    saveMeshToAssets: true);

// Batch processing
var batchResult = LODGeneratorCore.ProcessBatch(
    gameObjectArray,
    settings,
    progressCallback: (progress, status) => Debug.Log($"{progress:P0} - {status}"),
    saveMeshesToAssets: true
);

// Save/Load custom presets
settings.SaveAsPreset("MyCustomPreset");
settings.LoadPreset("MyCustomPreset");

// Get available custom presets
string[] presets = LODGeneratorSettings.GetCustomPresetNames();

// Check mesh renderer type
var type = LODGeneratorCore.GetMeshRendererType(gameObject);
if (type == MeshRendererType.SkinnedMeshRenderer)
{
    Debug.Log("This is a skinned mesh!");
}

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Requirements

Requirement	Version
Unity	2021.3 LTS or newer
UnityMeshSimplifier	Latest from GitHub
Platform	Editor only (runtime not required)

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Troubleshooting

"Object does not have a valid mesh"

Cause: The selected object is missing required components.

Solution: Ensure the object has either:

• MeshFilter + MeshRenderer components, OR
• SkinnedMeshRenderer component

LOD transitions are too aggressive/subtle

Cause: Default transition heights don't match your use case.

Solution:

• Adjust Screen Transition Heights in Advanced Settings
• Try a different preset (Quality = gradual, Performance = aggressive)

Simplified mesh looks bad

Cause: Some mesh topologies don't simplify well at low quality.

Solution:

• Increase the quality factor
• Try Quality preset instead of Performance
• Some meshes (with complex topology) may need manual LOD creation

Skinned mesh animations break after LOD generation

Cause: Skeleton hierarchy or bone references were not preserved.

Solution:

• Ensure the original skeleton hierarchy is preserved
• Check that bone references are correctly assigned
• Verify the original SkinnedMeshRenderer has valid bone weights

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FAQ

Q: Can I use this at runtime in my game?

A: No, this is an Editor-only tool. The generated LOD groups work at runtime, but the generation process must happen in the Unity Editor.

Q: Where are my custom presets saved?

A: By default, presets are saved to Assets/Editor/AutoLODGenerator/Presets/ in your project. This location survives package updates. You can change this in the Presets tab.

Q: Will my old presets work after updating the package?

A: Yes! The plugin automatically detects and migrates presets from the old location to the new location.

Q: Does this work with procedural/mesh-animated objects?

A: Yes, as long as the mesh has valid geometry. The simplified mesh will maintain the same structure as the original.

Q: Can I edit the generated meshes?

A: Yes, if you enable "Save Meshes to Assets", the meshes are saved as .asset files and can be modified like any other mesh asset.

Q: What mesh formats are supported?

A: Any mesh that Unity can import (FBX, OBJ, DAE, etc.) as long as it's a valid mesh with triangles.

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Contributing

Contributions are welcome! Please read our Contributing Guidelines before submitting issues or pull requests.

Development Setup

1. Clone this repository
2. Create a new Unity 2021.3+ project (or use an existing one)
3. In Package Manager, click + > Add package from disk and select the package.json at the repo root
4. Install the UnityMeshSimplifier dependency
5. Import the demo scene from Package Manager > Auto LOD Generator > Samples
6. Make your changes and submit a pull request

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Changelog

See CHANGELOG.md for version history and release notes.

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License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.

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Credits

• Built on UnityMeshSimplifier by Mattias Edlund