Maya to UE5 Exporter

A Python-based Maya tool that simplifies the process of exporting selected 3D meshes from Autodesk Maya to Unreal Engine 5. This tool provides a custom UI allowing you to configure FBX export settings, transform values, texture export options, and metadata before exporting.

Features

1. Maya Export Settings

   • Enable or disable smoothing groups, tangents, and instance preservation.
   • Adjust transform settings (rotation, scale, translation) to suit Unreal Engine's coordinate system.

2. Texture Export

   • Optionally export and/or copy all relevant textures to a specified folder.
   • Each export groups textures under a folder named after the asset.

3. Metadata & JSON Preview

   • Store additional metadata (author, project, version, custom properties) in a JSON file alongside the exported FBX.
   • Live preview of the JSON settings within the UI.
   • Copy the JSON directly to your clipboard if needed.

4. Unreal Import Settings

   • Provide hints for collision generation, lightmap UVs, and uniform scaling to guide the Unreal import process.

5. Simple UI

   • Built with PySide2/Qt for an intuitive, Maya-native interface.
   • Real-time selection updates and status feedback.

Installation

1. Requirements

   • Maya 2017+
   • Maya's fbxmaya plugin (comes standard with Maya, must be loaded).
   • PySide2 for UI.
   • shiboken2 for QWidget wrapping.

2. Script Setup

   • Place the MayaUE5Exporter.py script in a location accessible to Maya (e.g., in your Maya scripts folder).
   • (Optional) Add that folder to your Maya PYTHONPATH or your userSetup file so it can be easily imported.

3. Load Plugin

   • In Maya, ensure the fbxmaya plugin is enabled:

     cmds.loadPlugin('fbxmaya')

Usage

Opening the UI

In a Python tab within Maya's Script Editor or a shelf button, run:

import MayaUE5Exporter
MayaUE5Exporter.show_exporter()

Note: If you placed the file under a different name/path, adjust the import statement accordingly.

UI Overview

1. Export Path

   • Choose or type the destination FBX file path.

2. Asset Naming

   • Optionally specify a custom asset name. If left blank, the exporter will use the base name of your chosen file path.

3. Maya Export Settings

   • Smoothing Groups: Preserves smoothing group data.
   • Export Tangents: Exports tangents and binormals.
   • Preserve Instances: Maintains instances within the exported FBX.

4. Transform Settings

   • Rotation (X/Y/Z): Adjust the exported mesh's rotation.
   • (Future) Scale / Translation: Currently locked to default in the sample, but you can extend if needed.

5. Additional Metadata

   • Author, Project, Version, Description: Enter freeform text for metadata.
   • Tags: Add comma-separated tags.
   • Custom Properties: Add key-value pairs that will be stored in the JSON.

6. Texture Settings

   • Export Textures: Toggle texture exporting.
   • Texture Folder: Choose a directory where textures should be saved.
   • Copy Textures to Export Path: Copy the used textures to the designated folder.

7. Unreal Import Settings

   • Auto Generate Collision: Suggest collision generation in Unreal.
   • Generate Lightmap UVs: Suggest automatic lightmap UV creation.
   • Scale Factor: Suggest a uniform scale in Unreal (multiplies the imported mesh size).

8. JSON Preview

   • Shows the combined configuration in real-time.
   • Use Copy JSON to copy to your clipboard.

9. Buttons

   • Reset to Defaults: Restores the default settings.
   • Export: Exports selected objects to an FBX and writes a JSON alongside the exported file.

Exporting

1. Select Objects: In Maya's viewport or Outliner, select the objects you want to export.
2. Configure Settings: Adjust any relevant export, texture, or metadata settings in the UI.
3. Set Export Path: Click Browse next to Export Path, then pick/enter an .fbx filename.
4. (Optional) Set Texture Path: If exporting textures, define the folder or check Copy Textures.
5. Export: Press Export.
   • The FBX and a .json file (e.g., SM_MyAsset.fbx and SM_MyAsset_metadata_fbx.json) will be generated in the chosen directory.
6. Check Status: The status bar at the bottom indicates success or failure.

Default Settings

By default, the MayaUE5ExportSettings class initializes with:

{
    "geometry": {
        "smoothing_groups": true,
        "tangents_and_binormals": true,
        "preserve_instances": true,
        "preserve_edge_orientation": true,
        "turbosmooth": true
    },
    "coordinate_system": {
        "up_axis": "z",
        "unit_system": "cm"
    },
    "transform": {
        "rotation": [0, 90, 0],
        "scale": [1, 1, 1],
        "translation": [0, 0, 0]
    },
    "textures": {
        "export_textures": false,
        "texture_folder": "",
        "copy_textures": false
    },
    "unreal_import_settings": {
        "auto_generate_collision": true,
        "generate_lightmap_uvs": true,
        "import_materials": true,
        "import_textures": false,
        "combine_meshes": false,
        "normal_import_method": "ComputeNormals",
        "normal_generation_method": "MikkTSpace"
    },
    "metadata": {
        "author": "",
        "date_created": "",
        "project": "",
        "version": "",
        "description": "",
        "tags": [],
        "custom_properties": {}
    }
}

Some fields (e.g., preserve_edge_orientation, turbosmooth, etc.) are placeholders for potential future usage. Not all are exposed directly in the UI but can be controlled programmatically.

Customization

The exporter can be extended by editing MayaUE5ExportSettings:

• Adding Additional Settings
  Define new keys under default_settings and modify the get_maya_export_options() method or the UI to reflect those changes.

• Modifying the UI
  You can add more UI widgets to the UE5ExporterUI class to control new or existing settings. Be sure to hook them into update_json_preview() so changes appear in real time.

• Automation / Batch Export
  For batch operations, you can directly call MayaUE5ExportSettings.export_fbx(...) multiple times without opening the UI.

Troubleshooting

1. FBX Plugin Not Found

   • Ensure fbxmaya is loaded via Maya Plugin Manager or cmds.loadPlugin('fbxmaya').

2. No Objects Selected

   • The tool requires at least one object selected in Maya to export. Confirm your selection in the Outliner.

3. Texture Files Not Copied

   • Ensure the file nodes are properly connected and the file paths exist.
   • Confirm your destination folder is writable.

4. JSON Not Generated

   • Check for permission issues in the export directory.
   • The script creates a JSON next to the .fbx—verify you have write permissions.

License

This script is provided as-is under the MIT License. You are free to modify and distribute it. Attribution is appreciated but not required.

Happy exporting!