.. _Unreal Engine 4 Connect:

======================================
Unreal Engine
======================================

Overview
---------------

The |ue4_long| offer a simple toolkit for Unreal users to send and live sync their model data to an |nuc| server. This not only gives creators users a first class renderer through |presenter| or |composer| but also the ability to open, edit and sync with any of the Omniverse Connect applications. Now, depending on the use case, creators can choose the workflows and pipelines that work best for their needs while maintaining up to date revisions for all downstream consumers of their work.

.. raw:: html

      <div style="width: 100%;display: inline-block;position: relative;">
            <div id="dummy" style="margin-top: 56%;">
            </div>
            <div align="center">
            <div id="kaltura_player_1" style="position:absolute;top:0;left:0;left: 0;right: 0;bottom:0;border:solid thin black;"></div>
            <script type="text/javascript" src="https://cdnapisec.kaltura.com/p/2935771/embedPlaykitJs/uiconf_id/46302491"></script>
            <script type="text/javascript">
                  try {
                  var kalturaPlayer = KalturaPlayer.setup({
                  targetId: "kaltura_player_1",
                  provider:
                  { partnerId: 2935771, uiConfId: 46302491 }
                  });
                  kalturaPlayer.loadMedia(
                  {entryId: '1_9d03gj39'}
                  );
                  } catch (e)
                  { console.error(e.message) }
            </script>
            </div>
      </div>

The |ue4| plugins are an excellent way to export scene, geometry, and material content to USD and |omni|.  The MDL (Material Definition Language) plugin's material export unlocks access to using Unreal Engine's industry-leading material editor as one of the easiest and quickest ways to author MDL materials.  Artists can use Unreal Engine's terrain and landscape editor, and with one click can export geometry and materials straight to Omniverse, stored as a USD mesh.  The plugins also support USD and MDL importing as well as live-editing of meshes, materials, and stages.

Introduction (Video)
########################

.. raw:: html

    <div style="width: 100%;display: inline-block;position: relative;">
        <div id="dummy" style="margin-top: 56%;">
        </div>
        <div align="center">
        <div id="kaltura_player_2" style="position:absolute;top:0;left:0;left: 0;right: 0;bottom:0;border:solid thin black;"></div>
        <script type="text/javascript" src="https://cdnapisec.kaltura.com/p/2935771/embedPlaykitJs/uiconf_id/46302491"></script>
        <script type="text/javascript">
            try {
            var kalturaPlayer = KalturaPlayer.setup({
            targetId: "kaltura_player_2",
            provider:
            { partnerId: 2935771, uiConfId: 46302491 }
            });
            kalturaPlayer.loadMedia(
            {entryId: '1_zf34bemy'}
            );
            } catch (e)
            { console.error(e.message) }
        </script>
        </div>
    </div>

Supported Versions
##################

The |ue4| works in the following **Windows** versions of Unreal Editor:

- ``4.27``
- ``5.0``
- ``5.1``

.. important:: Currently, there are no versions of this |connector_short| available for Linux.

USD and MDL in Unreal Engine
##############################

USD assets are used by |omni| USD Actors, just like a Static Mesh is used by a Static Mesh Actor.  MDL assets are at first identified with this Omniverse MDL icon.  Once they are imported they are represented by an Unreal Material asset icon.

Note that red folders and USD/MDL assets with a lock on them identify read-only files that are located on an |nuc| mount.

.. image:: /content/images/connect_ue4_usd_type.png
      :align: center
      :alt: Omniverse USD and MDL asset icons


Assets Loading and Caching
###############################

Assets are not actually loaded and converted from Omniverse until they are used. Once loaded, the converted Unreal assets, such as textures, materials, are cached on disks. And they will be updated when necessary.  Note that the Content Browser displays USD and MDL files inside the project's */Content/Omniverse* folder, but those files do not exist on disk.  As assets are loaded, intermediate Unreal assets are saved to those locations, but the are purely intermediate and only aid in reload times.  Do not create assets within the */Content/Omniverse* folder as they could be removed from disk when these folders are cleaned.


A Note about the Epic Games USDImporter Plugin
##############################################

:guilabel:`Introduced in 102.1`

In version 102.1 of the 4.x Omniverse USD Plugins the USD library was modified with prefixed library names to allow the Epic USD plugins to run together with the Omniverse plugins.  Note that some export functionality (File : Export : .usd) may be impacted due to the registration order of UExporter extensions.

:guilabel:`Introduced in 201.0`

In version 201.0 of the 5.x Omniverse USD Plugins the Epic USDImporter plugins are now *required* because they are using Epic's USD libraries.  

      * 5.0 - USD 21.08 with Python 3.9
      * 5.1 - USD 22.08 with Python 3.9

Topics
--------------

.. toctree::
      :titlesonly:
      :maxdepth: 1

      ue4/manual.rst
      ue4/supported-features.rst
      ue4/release-notes.rst