Blender To Unity FBX Exporter

FBX exporter add-on for Blender 2.80+ compatible with Unity's coordinate and scaling system. Exported FBX files are imported into Unity with the correct rotations and scales.

How to install

1. Clone the repository or download the add-on file blender-to-unity-fbx-exporter.py to your device.
2. In Blender go to Edit > Preferences > Add-ons, then use the Install… button and use the File Browser to select the add-on file.
3. Enable the add-on by checking the enable checkbox.

How to use

Hit F9... or go to File > Export > Unity FBX (.fbx)

Exports all Empty, Mesh and Armature objects in the current scene except those in excluded collections. The full hierarchy is properly preserved and exported, including local positions and rotations.

Notes

• This is a customized version with less options and some fixes. Changes include:

  • No save options
  • F9 keymapping for quick exporting
  • Fixed an undo registration issue

• Not tested with armatures nor animations. Feel free to open an issue with a simple repro scene if you encounter any problem.

• Negative scales are imported with an unexpected but equivalent transform. Example: scale (-1, 1, 1) and no rotation is imported as scale (-1, -1, -1) and rotation (-180, 0, 0). This is equivalent, and may be changed to, the original scale (-1, 1, 1) and rotation (0, 0, 0) in Unity.

How it works

The exporter modifies the objects in the Blender scene right before exporting the FBX file, then reverts the modifications afterwards.

Every object to be exported receives a rotation of +90 degrees around the X axis in their transform without actually modifying the visual pose of its geometry and children. This is done in the root objects, then recursively propagated to their children (as they inherit a -90 rotation after transforming their parent). The modified scene is then exported to FBX using Blender's built-in FBX exporter with the proper options applied. Finally the scene is restored to the state before the modifications.

When Unity imports the FBX file all objects receive a rotation of -90 degrees in the X axis to preserve their visual pose. As the objects in the FBX already have a rotation of X+90 then the undesired rotation is canceled and everything gets imported correctly.

Why not use the "Experimental - Apply Transform" option?

This option doesn't work with object hierarchies of more than 2 levels. Objects beyond the 2nd level keep receiving unwanted rotations and scalings when imported into Unity.

Tested:

• Mixed EMPTY and MESH hierarchies with depth > 3
• Local rotations
• Non-uniform scaling
• Multi-user meshes, with and without modifiers
• Partial selections (Selected Objects Only)
• Hidden objects and collections (eye icon in the outliner).
• Disabled objects (monitor icon in the outliner). Imported with MeshRenderer disabled in Unity.
• Disabled collections (monitor icon in the outliner).
• Excluded collections (unchecked in the outliner). Won't be exported.
• Nested collections
• Objects with their parent in a disabled/excluded collection
• Mesh modifiers

About the author

Angel "Edy" Garcia
@VehiclePhysics
https://vehiclephysics.com