LOD GENERATOR v2.0

Overview

LOD GENERATOR v2.0 is a professional Blender addon designed to streamline the creation of Level of Detail (LOD) meshes for game development and real-time rendering. The addon provides an intuitive interface for generating multiple LOD levels and exporting them directly to Unity, Unreal Engine, and AR/VR platforms.

Key Benefits

• Time-Saving: Automate the tedious process of creating multiple LOD versions
• Professional Workflow: Industry-standard presets and optimization methods
• Engine Integration: Direct export with proper axis orientation and metadata
• Real-Time Preview: Visualize LOD switching based on camera distance
• Flexible Control: Custom presets or manual control over every LOD level

Installation

Requirements

• Blender: 4.1.0 or higher
• Python: 3.10+ (included with Blender)
• Operating System: Windows, macOS, or Linux

Installation Steps

1. Download the Addon
   • Download the lod_generator folder or ZIP file
2. Install in Blender
   • Open Blender
   • Go to Edit > Preferences > Add-ons
   • Click Install... button
   • Navigate to and select the lod_generator folder (or ZIP file)
   • Click Install Add-on
3. Enable the Addon
   • In the Add-ons list, search for "LOD GENERATOR"
   • Check the checkbox next to "LOD GENERATOR v2.0"
   • The addon is now active
4. Access the Panel
   • Press N in the 3D Viewport to open the sidebar
   • Click on the "LOD Generator" tab

Quick Start Guide

Basic LOD Generation

1. Select Your Mesh
   • Select one or more mesh objects in your scene
2. Open the LOD Generator Panel
   • Press N to open the sidebar
   • Click the "LOD Generator" tab
3. Choose a Preset
   • Select a preset from the dropdown (e.g., "Mobile (Performance)")
4. Generate LODs
   • Click the "Generate LODs" button
   • Your LOD versions will be created with the naming convention: ObjectName_LOD0, ObjectName_LOD1, etc.

Export to Game Engine

1. Select LOD Objects
   • Select all LOD versions you want to export (including the base mesh)
2. Configure Export Settings
   • Choose your target engine (Unity/Unreal/AR-VR)
   • Select export format (FBX/GLB/OBJ)
   • Set the export path
3. Export
   • Click "Prepare & Export"
   • Files will be exported to your specified directory

Features

LOD Generation Features

8 LOD Levels

Generate up to 8 different LOD levels for maximum flexibility. Each level can be individually enabled/disabled and configured.

Preset Configurations

Preset	LOD Levels	Use Case
Mobile (Performance)	100/50/25/10	Mobile games, low-end devices
Console/PC Balanced	100/70/40/20	Balanced performance for most games
High-End PC (Cinematic)	100/80/60/40	High-quality visuals, PC games
VR/AR Optimized	100/75/50/30	Virtual and augmented reality
Strategy/RTS	100/60/30/10	Strategy games with many units
Ultra Mobile	100/40/15/5	Extreme optimization for mobile
Custom	User-defined	Full manual control

Optimization Methods

1. Collapse (Recommended)
   • Merges vertices to reduce polygon count
   • Best for most mesh types
   • Preserves overall shape well
2. Un-Subdivide
   • Reverses subdivision operations
   • Best for grid-like or regularly subdivided meshes
   • May not work well on irregular geometry
3. Planar
   • Reduces flat surfaces by dissolving coplanar faces
   • Best for architectural models and hard-surface objects
   • Uses angle limit of ~5 degrees

Preservation Options

• Preserve UVs: Maintains UV mapping during reduction
• Preserve Volume: Attempts to maintain object volume
• Preserve Materials: Copies materials from original to LOD versions
• Vertex Group Protection: Protect specific areas from reduction using vertex groups

Distance Preview

• Real-time preview of LOD switching based on camera distance
• Visualize how LODs will switch in your game
• Adjustable distance threshold
• Exit preview mode with ESC or Right Mouse Button

Export Features

Supported Engines

1. Unity
   • FBX export with correct axis orientation (Forward: -Z, Up: Y)
   • LODGroup component metadata generation
   • Prefab metadata file generation
   • Automatic transform baking
2. Unreal Engine
   • FBX export with Unreal axis setup (Forward: -X, Up: Z)
   • LOD system integration metadata
   • Blueprint metadata file generation
   • Optimized for Unreal's static mesh system
3. AR/VR Platforms
   • GLB format (recommended for WebXR, AR, VR)
   • Mobile optimization settings
   • Manifest file generation
   • Animation support

Export Formats

• FBX: Industry standard, works with Unity and Unreal
• GLB: Binary GLTF, optimized for AR/VR and web
• OBJ: Universal format, includes automatic texture copying

Export Options

• Bake Transforms: Apply all transforms before export
• Preserve Hierarchy: Maintain object hierarchy in export
• Group LODs: Group all LODs under a parent empty
• Custom Group Name: Name the LOD group container

User Guide

LOD Generation Workflow

Step 1: Prepare Your Mesh

Before generating LODs, ensure your mesh is ready:

• Apply Modifiers: Apply any modifiers you want included in the base mesh
• Check Topology: Clean topology works best for decimation
• Set Up Materials: Materials will be preserved if enabled
• Create Vertex Groups (Optional): Mark areas to protect from reduction

Step 2: Configure LOD Settings

1. Select Preset or Use Custom
   • Choose a preset that matches your target platform
   • Or select "Custom" for manual control
2. Enable Desired LOD Levels
   • Check the boxes for LOD levels you want to generate
   • LOD0 is typically the highest quality (100%)
3. Adjust Percentages (if using Custom)
   • Set reduction percentage for each enabled LOD
   • Lower percentages = fewer polygons
4. Configure Optimization
   • Select optimization method (Collapse/Un-Subdivide/Planar)
   • Enable preservation options as needed
   • Set vertex group for protection (optional)

Step 3: Generate LODs

1. Select Target Objects
   • Select one or more mesh objects
   • You can generate LODs for multiple objects at once
2. Click "Generate LODs"
   • Progress bar will show generation progress
   • Each LOD will be created as a separate object
   • Objects are named: OriginalName_LOD0, OriginalName_LOD1, etc.
3. Review Results
   • Check the generated LODs in the viewport
   • Verify polygon counts match expectations
   • Adjust settings and regenerate if needed

Step 4: Preview LODs (Optional)

1. Enable Distance Preview
   • Check "Distance Preview" in the Preview section
   • Adjust preview distance slider
2. Start Preview
   • Click "Preview LODs" button
   • Select camera if multiple cameras exist
   • Move camera to see LOD switching
3. Exit Preview
   • Press ESC or Right Mouse Button
   • Or click "Exit Preview" button

Export Workflow

Step 1: Select Objects for Export

• Select all LOD versions you want to export
• Include the base mesh if needed
• You can select multiple objects

Step 2: Configure Export Settings

1. Target Engine
   • Select Unity, Unreal, or AR/VR
   • This affects axis orientation and metadata
2. Export Format
   • FBX for Unity/Unreal
   • GLB for AR/VR (recommended)
   • OBJ for general compatibility
3. Export Path
   • Set the directory where files will be saved
   • Use absolute path (required)
   • Path will be created if it doesn't exist
4. Advanced Settings
   • Bake Transforms: Apply transforms before export
   • Preserve Hierarchy: Keep object parent-child relationships
   • Group LODs: Create parent empty for all LODs
5. Engine-Specific Settings
   • Unity: Use LODGroup Component, Generate Prefab
   • Unreal: Use LOD System, Generate Blueprint
   • AR/VR: Optimize for Mobile, Generate Manifest

Step 3: Export

1. Click "Prepare & Export"
   • Objects will be prepared (transforms baked, hierarchy organized)
   • Export will begin
   • Progress will be shown in Blender's status bar
2. Check Export Directory
   • Navigate to your export path
   • Verify files were created
   • Check for metadata files (prefab.json, blueprint.json, manifest.json)
3. Import to Game Engine
   • Import the exported file into your game engine
   • Set up LOD groups using the metadata files (if generated)
   • Configure LOD distances in your engine

Mesh Statistics Display

The UI panel displays real-time statistics for the selected mesh:

• Polygons: Current polygon count
• Vertices: Current vertex count
• Estimated Stats: For each LOD level, shows estimated polygon and vertex counts based on reduction percentage

This helps you plan your LOD strategy before generation.

Technical Reference

File Structure

lod_generator/├── __init__.py          # Addon initialization and registration├── manifest.toml        # Blender Marketplace manifest├── properties.py        # Property definitions and presets├── operators.py         # Operator registration wrapper├── lod_creation.py      # LOD generation operators├── Smart_export.py      # Export operators└── ui_panel.py          # User interface panel

Operators

LOD Generation Operators

smartasset.generate_lods

• Generates LOD versions for selected objects
• Parameters: Controlled via scene properties
• Returns: {'FINISHED'} on success, {'CANCELLED'} on error

smartasset.preview_lod_distance

• Starts modal preview of LOD switching
• Parameters: Camera selection (if multiple cameras)
• Returns: {'RUNNING_MODAL'} while active

smartasset.exit_lod_preview

• Exits LOD preview mode
• Returns: {'FINISHED'}

Export Operators

smartasset.convert_to_game_export

• Prepares and exports LOD assets
• Parameters: Controlled via scene properties
• Returns: {'FINISHED'} on success, {'CANCELLED'} on error

smartasset.export_error_popup

• Displays export error messages
• Internal operator, called automatically

Properties

All properties are stored in context.scene.smartasset:

LOD Properties

• lod_preset: Enum - Preset selection
• lod0_enabled through lod7_enabled: Bool - Enable flags for each LOD
• lod0 through lod7: Float - Reduction percentages (1-100)
• optimization_method: Enum - Collapse/Un-Subdivide/Planar
• preserve_uvs: Bool - Preserve UV mapping
• preserve_volume: Bool - Preserve volume
• preserve_materials: Bool - Preserve materials
• vertex_group: String - Vertex group name for protection
• use_distance_preview: Bool - Enable distance preview
• preview_distance: Float - Distance threshold for preview

Export Properties

• export_engine: Enum - Unity/Unreal/ARVR
• export_format: Enum - FBX/GLB/OBJ
• export_path: String - Export directory path
• bake_transforms: Bool - Bake transforms before export
• preserve_hierarchy: Bool - Preserve object hierarchy
• group_lods: Bool - Group LODs under parent empty
• lod_group_name: String - Name for LOD group

Unity-Specific

• unity_use_lod_group: Bool - Generate LODGroup metadata
• unity_generate_prefab: Bool - Generate prefab metadata

Unreal-Specific

• unreal_use_lod_system: Bool - Generate LOD system metadata
• unreal_generate_blueprint: Bool - Generate Blueprint metadata

AR/VR-Specific

• arvr_optimize_for_mobile: Bool - Apply mobile optimizations
• arvr_generate_manifest: Bool - Generate manifest file

Naming Conventions

• LOD Objects: OriginalName_LOD0, OriginalName_LOD1, etc.
• LOD Group: OriginalName_Group (or custom name)
• Exported Files: OriginalName.fbx, OriginalName.glb, etc.
• Metadata Files: OriginalName_prefab.json, OriginalName_blueprint.json, OriginalName_manifest.json

Export File Formats

FBX Export Settings

Unity:

• Axis Forward: -Z
• Axis Up: Y
• Apply Unit Scale: Yes
• Bake Space Transform: Yes
• Embed Textures: Yes

Unreal:

• Axis Forward: X
• Axis Up: Z
• Apply Unit Scale: Yes
• Bake Space Transform: Yes
• Embed Textures: Yes

GLB Export Settings

• Format: GLB (binary)
• Export Animations: Yes (if present)
• Export Materials: Yes
• Export Cameras: No
• Export Lights: No

OBJ Export Settings

• Export Materials: Yes
• Export Normals: Yes
• Export UVs: Yes
• Triangulated: Yes
• Textures: Automatically copied to export directory

Metadata File Formats

Unity Prefab JSON

{  "name": "ObjectName",  "lodGroup": {    "enabled": true,    "lods": [      {        "screenRelativeTransitionHeight": 1.0,        "renderers": ["ObjectName_LOD0"]      }    ]  }}

Unreal Blueprint JSON

{  "name": "ObjectName",  "lodSettings": {    "enabled": true,    "lods": [      {        "screenSize": 1.0,        "staticMesh": "ObjectName_LOD0"      }    ]  }}

AR/VR Manifest JSON

{  "name": "ObjectName",  "version": "1.0",  "platforms": ["webxr", "ar", "vr"],  "optimization": {    "mobile": true,    "lods": [      {        "level": 0,        "distance": 1.0,        "mesh": "ObjectName_LOD0"      }    ]  }}

Troubleshooting

Common Issues

LOD Generation Issues

Problem: "No objects selected" error

• Solution: Select at least one mesh object before generating LODs

Problem: "No LOD levels enabled" error

• Solution: Enable at least one LOD level checkbox before generating

Problem: LODs look distorted or broken

• Solution:
  • Try a different optimization method (Collapse usually works best)
  • Check mesh topology - clean up non-manifold geometry
  • Reduce the reduction percentage for that LOD level
  • Ensure "Preserve Volume" is enabled

Problem: Un-Subdivide doesn't work

• Solution: Un-Subdivide only works on regularly subdivided meshes. Use Collapse instead for irregular geometry.

Problem: Planar reduction removes too much

• Solution: Planar reduction is aggressive. Use Collapse for better results on most meshes.

Export Issues

Problem: "Export Path is empty or invalid" error

• Solution:
  • Set an absolute path (not relative)
  • Ensure the path doesn't contain invalid characters
  • Path must be at least 3 characters long
  • Use a valid directory path (e.g., C:\Exports\MyProject)

Problem: Export fails silently

• Solution:
  • Check Blender's console for error messages
  • Ensure you have write permissions to the export directory
  • Verify the export path exists or can be created

Problem: Exported file doesn't import correctly in game engine

• Solution:
  • Verify you selected the correct target engine
  • Check axis orientation matches your engine's requirements
  • Ensure "Bake Transforms" is enabled
  • Try exporting as OBJ for compatibility testing

Problem: Materials/textures missing in exported file

• Solution:
  • Ensure "Preserve Materials" is enabled during LOD generation
  • For OBJ export, textures are automatically copied
  • For FBX, ensure "Embed Textures" is enabled (default)
  • Check that materials use image textures (not procedural)

Preview Issues

Problem: Preview doesn't start

• Solution:
  • Ensure at least one camera exists in the scene
  • Check that LOD objects exist (objects with _LOD in name)
  • Verify "Distance Preview" checkbox is enabled

Problem: Preview doesn't exit

• Solution:
  • Press ESC or Right Mouse Button
  • Click "Exit Preview" button in the UI
  • If stuck, restart Blender

Problem: LODs don't switch in preview

• Solution:
  • Adjust the preview distance slider
  • Move the camera closer/farther from objects
  • Ensure multiple LOD levels exist for the object

Performance Tips

1. For Large Scenes: Generate LODs for objects one at a time to avoid memory issues
2. For Complex Meshes: Start with fewer LOD levels and lower reduction percentages
3. For Batch Processing: Use Blender's scripting API to automate LOD generation for multiple files
4. Export Optimization: Export LODs separately if you have many objects to avoid large file sizes

Known Limitations

1. Animation: LOD generation doesn't preserve animation data. Export animations separately if needed.
2. Armatures: Armatures are exported but LOD generation only affects mesh geometry, not bone structure.
3. Particle Systems: Particle systems are not included in LOD generation or export.
4. Modifiers: Modifiers must be applied before LOD generation for best results.
5. Texture Baking: The addon doesn't bake textures. Use Blender's texture baking tools separately if needed.

Examples

Example 1: Mobile Game Asset

Goal: Create LODs for a character model for a mobile game

Steps:

1. Select character mesh
2. Choose "Mobile (Performance)" preset
3. Enable LOD0, LOD1, LOD2, LOD3
4. Set optimization method to "Collapse"
5. Enable "Preserve UVs", "Preserve Volume", "Preserve Materials"
6. Generate LODs
7. Export as FBX for Unity with LODGroup enabled

Result: 4 LOD levels (100%, 50%, 25%, 10%) optimized for mobile performance

Example 2: VR Environment

Goal: Create LODs for environment objects in VR

Steps:

1. Select environment meshes
2. Choose "VR/AR Optimized" preset
3. Enable LOD0, LOD1, LOD2, LOD3
4. Set optimization method to "Collapse"
5. Enable all preservation options
6. Generate LODs
7. Use distance preview to test LOD switching
8. Export as GLB with mobile optimization enabled

Result: VR-optimized LODs with smooth distance-based switching

Example 3: Strategy Game Unit

Goal: Create LODs for RTS game units (many on screen)

Steps:

1. Select unit mesh
2. Choose "Strategy/RTS" preset
3. Enable LOD0, LOD1, LOD2, LOD3
4. Set optimization method to "Collapse"
5. Create vertex group for important features (face, weapons)
6. Set vertex group in "Protect Area"
7. Generate LODs
8. Export as FBX for Unity

Result: Aggressively optimized LODs with protected important features

Example 4: Custom LOD Setup

Goal: Create custom LOD levels for specific performance targets

Steps:

1. Select mesh
2. Choose "Custom" preset
3. Enable LOD0 (100%), LOD1 (80%), LOD2 (60%), LOD3 (40%), LOD4 (20%)
4. Set optimization method based on mesh type
5. Adjust preservation options as needed
6. Generate LODs
7. Test with distance preview
8. Export with appropriate engine settings

Result: Custom LOD setup tailored to specific needs

FAQ

General Questions

Q: Can I generate LODs for multiple objects at once?

A: Yes, select multiple mesh objects and click "Generate LODs". Each object will get its own set of LOD versions.

Q: Will LOD generation affect my original mesh?

A: No, the original mesh is never modified. LOD versions are created as new objects.

Q: Can I edit LODs after generation?

A: Yes, LOD objects are regular Blender objects. You can edit them, add modifiers, etc. However, regenerating LODs will create new objects.

Q: How do I delete LODs?

A: Select the LOD objects and press Delete, or use Blender's normal object deletion methods.

Q: Can I use this with Blender's built-in LOD system?

A: This addon creates separate objects for each LOD level, which is more flexible than Blender's built-in system. You can use both approaches if needed.

Export Questions

Q: Which format should I use for Unity?

A: FBX is recommended for Unity. The addon automatically sets the correct axis orientation.

Q: Which format should I use for Unreal?

A: FBX is recommended for Unreal. The addon automatically sets the correct axis orientation.

Q: Which format should I use for AR/VR?

A: GLB is recommended for AR/VR platforms, especially WebXR.

Q: Do I need to use the metadata files?

A: The metadata files (prefab.json, blueprint.json, manifest.json) are optional helpers. You can set up LOD groups manually in your game engine if preferred.

Q: Can I export animations with LODs?

A: Animations are exported with GLB format. For FBX, animations are included but LOD generation doesn't affect animation data.

Technical Questions

Q: What's the difference between Collapse, Un-Subdivide, and Planar?

A:

• Collapse: Merges vertices (best for most meshes)
• Un-Subdivide: Reverses subdivision (best for grid-like meshes)
• Planar: Reduces flat surfaces (best for architectural models)

Q: How does vertex group protection work?

A: Vertices in the specified vertex group are protected from reduction, preserving important features like faces or details.

Q: What does "Preserve Volume" do?

A: It attempts to maintain the object's overall volume during reduction, preventing the mesh from collapsing inward.

Q: Can I use this with sculpted meshes?

A: Yes, but results may vary. High-detail sculpted meshes may need manual cleanup after LOD generation.

Q: Does this work with modifiers?

A: Modifiers should be applied before LOD generation for best results. The addon applies modifiers during export if "Use Mesh Modifiers" is enabled.

Performance Questions

Q: How many LOD levels should I create?

A: Typically 3-4 LOD levels are sufficient. More levels provide finer control but increase file size and setup complexity.

Q: What reduction percentages should I use?

A: This depends on your target platform and performance requirements. Use the presets as starting points and adjust based on testing.

Q: Will LODs improve my game's performance?

A: Yes, LODs can significantly improve performance by reducing polygon count for distant objects. However, proper LOD distance setup in your game engine is crucial.

Q: How do I set LOD distances in my game engine?

A: Use the metadata files as reference, or set up LOD groups manually in Unity/Unreal. Distances depend on your game's scale and camera setup.