Improvements to Unity <-> Blender <-> FBX <-> Blendfile workflows. See readme.txt.

readme.md

Improvements to Unity <-> Blender <-> FBX <-> Blendfile workflows.

Using .blend files in Unity projects is slow and overall not great practice. Ideally, you could double click a model in a project, edit it in Blender, hit save, then see the results back in Unity. That's what these scripts help with.

You'll need to associate .blend~ files with Blender in your OS for this to fully work.

BlenderSupportFunctions.cs

Add to your Unity projects.

FUNCTIONS

• Automatically renames any .blend to .blend~ to have the AssetDatabase ignore it.
• Lets you double click an FBX to open its associated .blend~ in Blender (only works if the .blend~ file association is setup).

auto_fbx_export.py

Add this to your Blender Default Startup File.

FUNCTIONS

• Automatically exports an FBX file for any .blend~ file on save.

auto_fbx_export.py

import bpy
import os

def export_fbx():
    # We only want the auto FBX export when working with .blend~ files specifically
    blend_file_path = bpy.data.filepath
    if not blend_file_path.endswith(".blend~"):
        return
    
    blend_file_name = os.path.basename(blend_file_path)
    blend_file_name_without_extension = os.path.splitext(blend_file_name)[0]
    directory = os.path.dirname(blend_file_path)
    fbx_file_path = os.path.join(directory, f"{blend_file_name_without_extension}.fbx")
    
    bpy.ops.export_scene.fbx(
        filepath=fbx_file_path,
        
        # Export entire scene, not just selected objects
        use_selection=False,
        
        global_scale=1.0,
        
        apply_unit_scale=True,
        
        apply_scale_options='FBX_SCALE_ALL',
        
        object_types={'MESH', 'ARMATURE', 'EMPTY', 'OTHER'},
        
        # Apply mesh modifiers during export
        use_mesh_modifiers=True,
        
        # Smoothing algorithm for mesh export
        mesh_smooth_type='FACE',
        
        bake_space_transform=True,
        
        # Add leaf bones at end of chains
        add_leaf_bones=False,
        
        # Primary axis for bones
        primary_bone_axis='Y',
        
        # Secondary axis for bones
        secondary_bone_axis='X',
        
        # Export only deform bones of armature
        use_armature_deform_only=True,
        
        # Export custom properties
        use_custom_props=True,
        
        # Path mode for textures and linked files
        path_mode='AUTO'
    )
    print(f'Saved FBX "{fbx_file_path}"')

# Callback function for save event
def on_save_pre(scene):
    export_fbx()

# Register the callback
bpy.app.handlers.save_pre.append(on_save_pre)

print("Registered auto_fbx_export.py")

BlenderSupportFunctions.cs

using System;
using System.Diagnostics;
using System.IO;
using Unity.Logging;
using UnityEditor;
using UnityEditor.Callbacks;
using UnityEngine;
using Debug = UnityEngine.Debug;

public class BlenderSupportFunctions : AssetPostprocessor
{
    #region Methods

    [OnOpenAsset]
    private static bool OpenFbx(int instanceID)
    {
        var assetPath = AssetDatabase.GetAssetPath(instanceID);
        return assetPath.EndsWith(".fbx") && TryOpenBlendFileForFbx(assetPath);
    }

    private static bool TryOpenBlendFileForFbx(string assetPath)
    {
        var name = Path.GetFileNameWithoutExtension(assetPath);
        name += ".blend~";
        var directoryName = Path.GetDirectoryName(assetPath);
        // skip "Assets/"
        directoryName = directoryName.Substring(7);
        directoryName = $"{Application.dataPath}/{directoryName}";
        var finalPath = $"{directoryName}/{name}";
        finalPath = finalPath.Replace('\\', '/');
        try
        {
            Process.Start(finalPath);
        }
        catch (Exception e)
        {
            Debug.LogError($"Exception thrown while opening blendfile at path: {finalPath}");
            Debug.LogException(e);
            return false;
        }

        return true;
    }

    private void OnPreprocessAsset()
    {
        if (!assetPath.EndsWith(".blend"))
        {
            return;
        }

        var name = Path.GetFileName(assetPath);
        name += "~";
        var directoryName = Path.GetDirectoryName(assetPath);
        var finalPath = $"{directoryName}/{name}";
        finalPath = finalPath.Replace('\\', '/');
        Log.Info(finalPath);
        File.Move(assetPath, finalPath);
    }

    #endregion
}