Known Issues

MetaHuman Creator

MetaHuman Character Plugin Not Available on Linux

The MetaHuman Character plugin does not build on Linux. 

Workaround
A workaround is not available at this time.

Crash When Using UEFN Export and UEFN Island is Loaded

Unreal Engine will crash while running the UEFN Export assembly process if the UEFN island is loaded.

Workaround
Ensure UEFN is closed whilst running the UEFN Export assembly process.

UEFN Export Assembly Cannot Reference Assets From Other Plugins

The UEFN Export assembly process will fail if the MetaHuman Character references assets (for example, as part of the wardrobe) that are part of another plugin.

Workaround
Only reference assets from the current project or that are part of the MetaHuman Creator plugin.

MetaHuman Blueprint not fully updated when assembling with a different quality

When assembling a MetaHuman with a different quality level, the LOD Sync Component will not be updated to reflect the new quality. Grooms might not be rendered correctly if changing from a higher to lower quality as the LOD Sync Component will select the wrong groom to display.

Workaround
Delete the blueprint prior to assembling, or assemble the MetaHuman with a different name to create a new Blueprint.

Invalid Arguments Error When Autorigging

Using the conform workflow with a mesh that has zero polygon areas will lead to an “Invalid Arguments” error when autorigged.

Workaround
Find and then fix any zero polygon areas in the mesh by inspecting mesh degeneration. In Maya for example you can use “Cleanup Options” > “Faces with zero geometry area” checkbox. There are also various other ways to check mesh degeneration which you may prefer.

MetaHuman Modules are Rebuilt

MetaHuman modules are rebuilt in the installed engine from the Epic Games Launcher on new C++ projects.

Workaround
No workaround other than to let the engine rebuild

MetaHuman Animator

Two MetaHumans in an Exported Level Sequence

When exporting a Level Sequence from MetaHuman Performance, two MetaHumans may be visible in the scene.

Workaround
Move the exported MetaHuman in level while Level Sequence is open

Incorrect Skeletal Mesh Rotation After Using Mesh to MetaHuman from Template Mesh

When using the Mesh to MetaHuman from Template Mesh workflow, the orientation is incorrect in the SkeletalMesh asset editor and when solving animation using the MetaHuman Performance asset.  However, this does not affect the animation quality and once the performance processing takes place, the mesh gets correctly oriented.

Workaround
A workaround is not available at this time.

Realtime Live Link Face Source Won’t Connect to the Live Link Face iOS App if ARKit Mode is Active

When using the Live Link Face iOS app, the Live Link Face Source within UE/Live Link Hub will be unable to successfully connect if the iOS app is configured to use the ‘ARKit’ mode as opposed to the ‘MetaHuman Animator’ mode.

Workaround
Configure the Live Link Face iOS app to use the ‘MetaHuman Animator’ mode. To do this go to the settings screen within the app and under the ‘Capture’ section select ‘Mode’. Select ‘MetaHuman Animator’ and tap ‘Continue’. Note that this mode requires a device with a TrueDepth camera (i.e. a device which supports Face ID).

Changing Calibration in Capture Data Crash

Changing the calibration in the footage capture data asset can cause a crash during processing if the camera names in the calibration do not match those used in the performance. The camera names in the performance do not get updated automatically while the performance asset editor is closed.

Workaround
Only create the performance after the capture data has been finalized.

MetaHuman Animator Depth Processing Plugin Compilation

Users trying to compile Unreal Engine 5.6 from source will not be able to use the MetaHuman Depth Processing Plugin.

Workaround

The public MeshTrackerNodes(ReadOnlyTargetRules Target) : base(Target){ … is missing the bUsePrecompiled and PCHUsage checks. Navigate to the source folder of the plugin and locate the MeshTrackerNodes folder. In the MeshTrackerNodes.Build.cs file, Please add the following lines for the target rules:

bUsePrecompiled = true;
PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;

Invalid timecode after ingesting Live Link Face iOS 1.6.0 takes

Version 1.6.0 of Live Link Face for iOS now includes more flexible capture options including the ability to capture footage at a variety of target frame rates. When ingesting footage captured at rates other than 30 or 60 FPS the resulting image sequences and audio assets in UE will contain invalid timecode information. This will affect track alignment within the MetaHuman Animator identity and performance editors. 30 or 60 FPS takes will continue to be ingested correctly.

Workaround
Manually set the timecode of each asset type (video image sequence, depth image sequence, audio) using the contents of the frame_log.csv file contained within the relevant Live Link Face take, using the first video (V), depth (D) and audio (A) timecode values.

Incorrect video track duration after capturing high frame rate takes in Live Link Face 1.6.0

Version 1.6.0 of the Live Link face for iOS now includes more flexible capture options including the ability to capture footage at much higher frame rates than previously offered. On certain iOS devices this may result in dropped video frames being absent from the recorded .mov files due to system performance constraints. Whilst these takes will be ingested into UE without error, the video tracks will appear to have a shorter duration than expected when viewed within the MetaHuman Animator identity or performance editors. This will result in accelerated playback, unexpected animation results and audio misalignment.

Workaround
The simplest workaround is to re-record the take using a less demanding target frame rate, however if that is not possible then the take can be repaired outside of UE using ffmpeg. Note that the take will need to be re-ingested once the following modifications are made:

1. Ensure ffmpeg is installed on your system and available as part of the PATH environment variable.

2. Ensure you have a copy of the problematic Live Link Face take data on your PC.

3. Navigate to the location of the take and open the directory with PowerShell.

4. In PowerShell, prepare the following ffmpeg command:

   1. ffmpeg -noautorotate -i input.mov -q:v 3 -filter:v fps=90 -c:v mjpeg output.mov

   2. Be sure to specify the correct input.mov name for the given take, there should be a single .mov file within the take directory.

   3. Specify the relevant target frame rate for the fps= portion of the command.

5. Execute the command.

6. On completion make a note of the final frame=(number) value output by ffmpeg, we’ll use this to update the take metadata which is required for successful ingest into UE.

7. Open the take.json file within the take directory and update the value for the "frames" JSON property to match the final frame count produced by ffmpeg.

8. Rename the new output.mov file to match the name of the original .mov file within the take.

   • You will need to either delete or rename the original mov file. This file will no longer be used for ingest.

9. Ingest the take with the updated .mov file using the target archive ingest approach.

MetaHumans in Unreal Engine

Incorrect Face Texture on Android

A MetaHuman Character assembled using either the UE Cine or UE Optimized pipeline (and either High or Medium quality) may render with the incorrect face texture applied.  This is heavily dependent on hardware and might impact Android 10 devices more often than Android 11 or 12.

Workaround
Assemble the character using the UE Optimized pipeline and Low quality.

Textures removed from MetaHumans Assembled in non English Editor

When assembling a MetaHuman in an editor where the editor language is not English, the resultant MetaHuman will appear without textures in the viewport.

Workaround
Change editor language to English then reassemble the MetaHuman.

MetaHumans in UEFN

MetaHuman Characters Not Animating in UEFN

A MetaHuman Character assembled from MetaHuman Creator in Unreal Engine 5.6 using the UEFN Export assembly does not animate in UEFN.

Workaround
This can be resolved by manually saving the character’s blueprint in the UEFN project.  With the project open in UEFN, find the character’s blueprint asset in the Content Browser.  Either right click on the asset and select Save, or open the blueprint editor for the asset and click Save.

MetaHumans Exported to UEFN are without Grooms or Clothing

User generated grooms and clothing may not appear on MetaHumans that are exported for UEFN.

Workaround
Any user generated clothing or grooms should be manually assigned to the respective components of the MetaHuman Blueprint within the UEFN project after export.

MetaHumans on Fab

Missing Metadata When Verifying/Packaging Character Assemblies

The MHExportQuality metadata is not set correctly on the character blueprint during assembly (UE Cine or UE Optimized).  This means MetaHuman Manager is not able to determine the correct optimization level of the assembly.  

Workaround
After creating the character assembly;

1. In the Content Browser, select only the blueprint for the assembled character,

2. Navigate to the Console input bar, and set the format to Python

3. With the blueprint still selected, enter the following Python line into the console:

unreal.EditorAssetLibrary.set_metadata_tag(unreal.EditorUtilityLibrary.get_selected_assets()[0], "MHExportQuality", "High")

The final string (“High” in the example above) is the quality of the assembled character.  Accepted values to use here are Cinematic, High, Medium, or Low.

Without this workaround it is only possible to publish cinematic quality character assemblies.

Errors importing Character Assemblies

Importing a Character Assembly into a project which already contains Character Assemblies will result in broken references in the imported Character. 

Workaround
After import, manually fix up the broken references

Incorrect application of Import Paths project settings

The MetaHuman Import Path for Cinematic Characters will not be used, and the path configured for Optimized Characters will be used for all Character Assemblies regardless of quality level.

Workaround
A workaround is not available at this time.  

Missing textures for MetaHuman Clothing asset

After a MetaHuman Clothing asset gets imported from Fab to Unreal Project, its textures are missing.

Workaround

1. Download the .mhpkg from the FAB listing.

2. Create a folder called "Outfits" in your content folder, if you don't already have one. 

   Location: All>Content>Outfits, or /All/Game/Outfits (depending on how you are viewing it).

3. Create a folder in "Outfits" called "name_of_the_asset".

4. Drag _asset_.mhpkg into your new "name_of_the_asset" folder. It should unpack here.  

   Check to make sure that the name of the folder that is unpacked in this location is exactly the same name as the folder you created (in which you just unpacked into). 

   If they do not match, rename the folder you made (in Outfits) to match the unpacked folder name.

5. Drag the MetaHuman Wardrobe item (usually has the prefix “WI_”) into the Outfit Clothing section in MHC and double-click to apply it.

MetaHuman for Maya

Unreal Engine Crash When Importing DNA Without Geometry

Expression Editor in MetaHuman for Maya supports exporting a DNA and FBX file that can be imported directly into Unreal Engine as a Skeletal Mesh (without using MetaHuman Creator).  This DNA file does not contain geometry information.  Using this DNA file with the Skeletal Mesh asset will cause Unreal Engine to crash.

Workaround
Use a DNA file that does include geometry - this can be the DNA file saved at any other point in the Expression Editor workflow.  

Or, import the DNA file directly into MetaHuman Creator using the Conform > Import DNA option.