Unity Blender Animation Fix

"YOU MUST RERUN THE PYTHON SCRIPT IN ADMINISTRATOR MODE FOR EACH UNITY EDITOR VERSION YOU INSTALL OR UPDATE."

A standalone Python tool that fixes Unity's Blender importer bug where only the first animation action is imported from .blend files.

The Problem

Unity has a long-standing bug in its Blender integration where the internal Unity-BlenderToFBX.py script uses bake_anim_use_all_actions=False, causing only the first animation action to be imported when you drag a .blend file into Unity. This means multi-animation Blender files lose most of their animations during import.

The Solution

This tool automatically locates all Unity installations on your system and patches the problematic script to use bake_anim_use_all_actions=True, ensuring all animation actions are imported from Blender files.

Features

• Automatic Unity Detection: Finds all Unity versions installed via Unity Hub
• Safe Patching: Creates backup files before making any changes
• Permission Handling: Automatically requests administrator privileges when needed
• Cross-Version Support: Works with all Unity versions that use the Blender importer
• Detailed Reporting: Shows exactly which installations were patched successfully

Installation

1. Download unity_blender_fix.py
2. Ensure Python 3.x is installed on your system

Usage

• Close Unity and Unity Hub completely
• Run the script in admin mode:

  python unity_blender_fix.py

1. Or simply double-click the .py file
2. Grant administrator privileges when prompted
3. The script will automatically find and patch all Unity installations
4. Restart Unity - your Blender files will now import all animations

Requirements

• Python 3.x
• Windows (Unity Hub installation)
• Administrator privileges (script will request automatically)

What Gets Changed

The script modifies Unity-BlenderToFBX.py in each Unity installation:

# Before (broken)
bake_anim_use_all_actions=False

# After (fixed) 
bake_anim_use_all_actions=True

File locations:

C:\Program Files\Unity\Hub\Editor\{VERSION}\Editor\Data\Tools\Unity-BlenderToFBX.py

Safety

• Original files are backed up as .backup before modification
• No Unity installation files are deleted or corrupted
• Changes can be reverted by restoring backup files

Example Output

Unity Blender Animation Fix Tool
Fixes bake_anim_use_all_actions=False bug in Unity's Blender importer
------------------------------------------------------------

Found 3 Unity installation(s):
  2022.3.15f1: C:\Program Files\Unity\Hub\Editor\2022.3.15f1
  2023.2.8f1: C:\Program Files\Unity\Hub\Editor\2023.2.8f1
  2024.1.0f1: C:\Program Files\Unity\Hub\Editor\2024.1.0f1

Processing Unity 2022.3.15f1...
  Backup created: Unity-BlenderToFBX.py.backup
  Successfully patched!

Processing Unity 2023.2.8f1...
  Already patched or different format

Processing Unity 2024.1.0f1...
  Backup created: Unity-BlenderToFBX.py.backup
  Successfully patched!

==================================================
RESULTS SUMMARY
==================================================
Successfully patched:  2
Already fixed:         1
Permission errors:     0
Other errors:          0

SUCCESS! 2 Unity installation(s) fixed.
Your Blender files will now export all animations to Unity.

Troubleshooting

Permission Errors:

• Make sure Unity and Unity Hub are completely closed
• Run the script as Administrator
• Or run from an Administrator command prompt

Script Not Finding Unity:

• Ensure Unity is installed via Unity Hub
• Check if Unity is installed in a custom location (script checks common paths)

Backup Failed:

• The script will continue without backup if backup creation fails
• Original functionality is preserved even if patching fails

Contributing

This tool addresses a fundamental workflow issue for game developers using Blender animations in Unity projects. Feel free to submit issues or improvements.

License

MIT License - Feel free to use and modify as needed.