Asset Export to JSON - Unreal Engine Editor Extension

Overview

This editor extension provides a comprehensive asset export system that converts Unreal Engine assets to JSON format for LLM-based combat balance analysis. The feature extracts detailed data from various asset types to create text-based documentation that can be analyzed by AI systems.

Purpose: Enable comprehensive combat balance analysis by providing structured, text-based representations of game assets suitable for Large Language Model (LLM) processing.

Supported Asset Types:

• DataTable - Complete row and column data
• Blueprint - Variables, functions, components, event graphs with node connections
• AnimMontage - Sections, notifies, custom properties, slot animations
• CurveTable - Key-value curve data (RichCurves and SimpleCurves)

Features

Configuration-Based Export

• Project Settings Integration: Configure export paths in Edit → Project Settings → Plugins → Asset Export to JSON
• Persistent Configuration: Settings saved to Config/DefaultEditor.ini for team sharing via SVN/Git
• Multi-Folder Support: Export from multiple folder paths with single click
• Asset Type Filtering: Enable/disable specific asset types via settings

Comprehensive Data Extraction

Blueprint Export

• Variables with types and default values
• Functions with inputs/outputs
• Component hierarchy
• Event Graphs: Complete node graph with:
  • Node types, titles, positions, comments
  • Pin types, directions, default values
  • Connection graph between pins
  • Node-specific properties

AnimMontage Export

• Sections with start/end times
• Slot animation tracks with segments
• Notify Events: Complete notify data including:
  • Notify type and trigger times
  • Custom properties from notify classes
  • Blend in/out settings
  • Track indices and sync markers

CurveTable Export

• Support for both RichCurves and SimpleCurves
• Key data with time, value, tangent information
• Curve interpolation modes

Output Management

• Timestamped Exports: Optional timestamped subfolders for export history
• Type-Separated Files: Separate JSON files per asset type (DataTable.json, Blueprint.json, etc.)
• Pretty-Printed JSON: Human-readable formatting with indentation
• Duplicate Detection: Prevents duplicate exports when folders overlap

Installation

1. File Structure

Copy the following files to your project:

New Files (copy to Source/WorldStalkerEditor/Utility/):

AssetExportSettings.h
AssetExportSettings.cpp
AssetExporterToJSON.h
AssetExporterToJSON.cpp

Modified Files (merge changes manually):

• WorldStalkerEditor.h - See MERGE_INSTRUCTIONS.md
• WorldStalkerEditor.cpp - See MERGE_INSTRUCTIONS.md

2. Build Configuration

Add to your WorldStalkerEditor.Build.cs:

PublicDependencyModuleNames.AddRange(new string[] {
    "AssetRegistry",
    "Json",
    "JsonUtilities"
});

PrivateDependencyModuleNames.AddRange(new string[] {
    "UnrealEd",
    "Engine",
    "Slate",
    "SlateCore",
    "ToolMenus",
    "DeveloperSettings"
});

3. Rebuild Project

# Generate Visual Studio project files
GenerateVSProjectFile.bat

# Build the editor module
# Or rebuild from Visual Studio

Configuration

Step 1: Open Project Settings

Navigate to: Edit → Project Settings → Plugins → Asset Export to JSON

Step 2: Configure Export Paths

Export Folder Paths (Array):

• Add folder paths relative to /Game/ content directory
• Example paths:
  • Blueprints/Enemy
  • Blueprints/Characters
  • Blueprints/Abilities
  • DataTables
• Use the + button to add new paths
• Use the - button to remove paths

Default Paths (automatically configured):

Blueprints/Enemy
Blueprints/Characters
Blueprints/Abilities
DataTables

Step 3: Configure Output Settings

Output Directory:

• Default: Exports (relative to Content folder)
• Set custom path if desired

Create Timestamped Folder:

• Enabled: Creates subfolder like Export_2025_01_15_143022
• Disabled: Overwrites files in output directory

Step 4: Select Asset Types

Enable or disable export for specific asset types:

• ☑ Export DataTables
• ☑ Export Blueprints
• ☑ Export AnimMontages
• ☑ Export CurveTables

Usage

Quick Export

1. Open Unreal Editor
2. Navigate to: Tools → WorldStalker → Export Assets to JSON
3. Wait for export to complete (notification dialog will appear)

Export Output

Files are saved to: Content/Exports/ (or configured output directory)

Output Structure (with timestamped folder):

Content/
└── Exports/
    └── Export_2025_01_15_143022/
        ├── DataTable.json
        ├── Blueprint.json
        ├── AnimMontage.json
        └── CurveTable.json

Output Format Examples

DataTable.json

[
  {
    "AssetName": "DT_CharacterStats",
    "AssetPath": "/Game/DataTables/DT_CharacterStats",
    "RowCount": 10,
    "Columns": ["Name", "Health", "Attack", "Defense"],
    "Rows": {
      "Warrior": {
        "Name": "Warrior",
        "Health": "1000",
        "Attack": "150",
        "Defense": "100"
      }
    }
  }
]

Blueprint.json

[
  {
    "AssetName": "BP_Enemy_Goblin",
    "AssetPath": "/Game/Blueprints/Enemy/BP_Enemy_Goblin",
    "ParentClass": "WSCharacterBase",
    "Variables": [
      {
        "Name": "MaxHealth",
        "Type": "float",
        "DefaultValue": "500.0"
      }
    ],
    "EventGraphs": [
      {
        "GraphName": "EventGraph",
        "Nodes": [
          {
            "NodeTitle": "Event BeginPlay",
            "NodeClass": "K2Node_Event",
            "Pins": [...]
          }
        ],
        "Connections": [
          {
            "SourceNode": "Event BeginPlay",
            "SourcePin": "then",
            "TargetNode": "Set Max Health",
            "TargetPin": "execute"
          }
        ]
      }
    ]
  }
]

AnimMontage.json

[
  {
    "AssetName": "AM_Attack_Combo",
    "AssetPath": "/Game/Animations/AM_Attack_Combo",
    "SequenceLength": 2.5,
    "Sections": [
      {
        "SectionName": "Combo1",
        "StartTime": 0.0,
        "EndTime": 0.8
      }
    ],
    "Notifies": [
      {
        "NotifyName": "DamageNotify",
        "TriggerTime": 0.5,
        "NotifyType": "AnimNotify",
        "CustomProperties": {
          "DamageMultiplier": "1.5",
          "HitboxSize": "100.0"
        }
      }
    ],
    "SlotAnimTracks": [...]
  }
]

Troubleshooting

No Output Files Generated

Problem: Export completes but no JSON files are created Solution: Check that export paths contain assets of the enabled types

Duplicate Assets in Output

Problem: Same asset appears multiple times in JSON Solution: This is now prevented by duplicate detection - check for overlapping folder paths in settings

Build Errors After Integration

Problem: Compilation errors about missing headers Solution: Ensure all dependencies are added to .Build.cs file (see Installation section)

Export Hangs on Large Projects

Problem: Export takes very long time Solution: Reduce number of export paths or disable asset types not needed

Settings Not Persisting

Problem: Configuration resets after editor restart Solution: Check that Config/DefaultEditor.ini is writable and not locked

Technical Details

Unreal Engine Version

• Tested on: Unreal Engine 5.5.4 (Custom Build)
• API Compatibility: Uses UE 5.5+ CurveTable API (GetRichCurveRowMap/GetSimpleCurveRowMap)

Module Dependencies

• AssetRegistry - Asset discovery and filtering
• Json/JsonUtilities - JSON serialization
• UnrealEd - Editor integration
• ToolMenus - Menu extension system
• DeveloperSettings - Project settings integration

Performance Characteristics

• Recursive Search: Searches all subfolders of configured paths
• Memory Usage: Loads assets one at a time to minimize memory footprint
• Export Speed: ~10-50 assets per second depending on asset complexity

Blueprint Event Graph Extraction

The system traverses the Blueprint graph structure to extract:

• All nodes from UbergraphPages (event graphs)
• Node metadata (class, title, position, comments)
• Pin information (type, direction, default values)
• Connection graph between pins (LinkedTo relationships)
• Property values from graph nodes

AnimMontage Custom Property Extraction

Custom properties are extracted from Notify objects by:

1. Iterating through all AnimNotifyEvent entries
2. Reflecting on Notify object class properties
3. Filtering for editable properties (CPF_Edit flag)
4. Serializing property values to JSON

Known Limitations

1. Blueprint Visual Script Logic: Exports node graph structure but not visual script bytecode execution flow
2. Binary Assets: Cannot export binary data (meshes, textures, audio)
3. Complex Property Types: Some complex UObject properties may export as object references only
4. Large Blueprints: Very large blueprints with thousands of nodes may take significant time to export

Development History

Initial Release: INI-based configuration system with comprehensive asset extraction

Key Design Decisions:

• INI-based configuration chosen over checkbox UI for repeated use convenience
• UDeveloperSettings integration for team collaboration via version control
• Duplicate detection prevents redundant exports from overlapping folder paths
• Pretty-printed JSON for human readability and LLM processing

Support

For issues, questions, or feature requests:

1. Check this README and MERGE_INSTRUCTIONS.md
2. Review Output Log in Unreal Editor for error messages
3. Contact: jinilkim@actionsquare.com

License

Copyright Epic Games, Inc. All Rights Reserved. Part of the WorldStalker (DungeonStalkers) project.