This tutorial shows you how to retarget an Animation Asset that was developed for the Unreal Engine 4 (UE4) Mannequin to a MetaHuman. You can use this method to retarget any Animation Asset that uses the UE4 Mannequin’s Skeleton to any MetaHuman.
The Animation Assets used in this tutorial are from the MCO MoCap Basics pack, which you can download for free on the Unreal Engine Marketplace.
Required Knowledge and Setup
This page assumes you have some knowledge of the Skeletal Mesh animation system in Unreal Engine, as well as animation retargeting.
Before you can follow the steps outlined on this page, you need to do the following:
Create a new Unreal Engine project based on the Third Person Template. If you need help completing this step, refer to the following pages in the Unreal Engine 5 documentation:
Download a MetaHuman and import them into your project. If you need help completing this step, refer to the following pages:
For this tutorial, we will use the Ada MetaHuman Preset, but you can use any MetaHuman created with the latest version of MetaHuman Creator.
Workflow
The workflow consists of the following steps:
Set up the MetaHuman IK Rig to use the correct preview mesh.
Create and configure a UE4 Mannequin to MetaHuman IK Retargeter Asset.
Select an Animation Asset to retarget, then export it as a new retargeted Asset.
Configure the retargeted Animation Asset to use the correct Skeletal Mesh for your MetaHuman.
Set Up the MetaHuman IK Rig
In this step, you will configure the MetaHuman IK Rig Asset to use a preview mesh. A rig without a mesh will not appear in the Viewport.
Follow these steps:
In the Content Browser, search for the IK_MetaHuman IK Rig. By default, this Asset is located in the
MetaHumans/Common/Common
folder.Double-click the IK_MetaHuman IK Rig to open it.
In the Preview Scene Settings panel on the right, set the Preview Mesh property to the f_med_nrw_preview Skeletal Mesh.
Save and close this Asset.
Create and Configure an IK Retargeter Asset
In this step, you will create a new IK Retargeter Asset, using the RTG_UE4Manny_UE5Manny IK Retargeter as a starting point. This Asset will handle animation retargeting from the UE4 Mannequin Skeleton to the MetaHuman Skeleton.
The RTG_UE4Manny_UE5Manny is automatically added to your project if you created the project using either the Third Person or Top-Down template. Otherwise, you can migrate it from another project that was created using one of these templates.
In the Content Browser, search for the RTG_UE4Manny_UE5Manny IK Retargeter Asset. By default, this Asset is located in the
Characters/Mannequin_UE4/Rigs
folder.Right-click the RTG_UE4Manny_UE5Manny Asset and, from the context menu, select Duplicate. Name the duplicated Asset RTG_UE4Manny_MetaHuman.
Double-click the RTG_UE4Manny_MetaHuman Asset to open it. The Viewport shows you the UE4 and UE5 Mannequins overlapping, and you have several panels to configure retargeting settings on the right.
In the Details panel on the right, from the Target IKRig Asset drop-down, select IK_MetaHuman. This replaces the UE5 Mannequin in the Viewport with an untextured MetaHuman body mesh.
In the Details panel on the right, from the Target Preview Mesh drop-down, search for and select the preview mesh that corresponds to your MetaHuman.
As a reminder, all MetaHuman Skeletal Meshes follow the same naming convention:
gender-presentation_height_weight_mesh-purpose
. This tutorial uses the Ada Preset, whose attributes are as follows:gender-presentation:
f
height:
med
weight:
nrw
Preview meshes have the
\_preview
suffix.For this tutorial, the mesh you’re looking for is named
f_medium_nrw_preview
. Search for it in the dropdown and select it.In the Chain Mapping panel on the right, make sure the following properties are set to None:
LeftPinkyMetacarpal
LeftMiddleMetacarpal
LeftRingMetacarpal
LeftIndexMetacarpal
LeftLowerArmTwist02
LeftUpperArmTwist02
RightPinkyMetacarpal
RightRingMetacarpal
RightMiddleMetacarpal
RightIndexMetacarpal
RightLowerArmTwist02
RightUpperArmTwist02
At this point, you should see the UE4 Mannequin and the MetaHuman Skeletal Mesh in the Viewport, overlapping. Both meshes should be using the same A-pose.
If the MetaHuman pose is incorrect, make sure you selected the \_preview
Skeletal Mesh, not the \_body
Skeletal Mesh.
Retarget and Export an Animation Asset
Choose an Animation Asset
Still working with the RTG_UE4Manny_MetaHuman Asset in the editor, click the Asset Browser tab. This opens the Asset Browser panel, which contains all animations that are compatible with the source Skeleton.
The Asset Browser only shows animations compatible with the skeleton used by the source Skeletal Mesh. If your Unreal Engine project contains multiple copies of the same Skeletal Mesh, you need to set up the skeletons used by each copy to be compatible with each other. To learn how to do this, refer to the Compatible Skeletons section of the Skeletons in Unreal Engine 5 documentation.
Separate the Meshes in the Viewport
In the Details panel, set the X coordinate of the Target Mesh Offset option to a value that separates the Source and Target preview meshes and leaves enough distance between them to clearly observe the animation playing. In the GIF below, we set this value to 150
.
Preview the Animation
In the Asset Browser, double-click an Animation Asset to preview it in the Viewport. This tutorial uses the Walk_02_Cheerful_Loop_IP animation from the MCO MoCap Basics animation pack, but you can use any Animation Asset that is compatible with the UE4 Mannequin skeleton.
You should now see the animation playing in the Viewport:
Make Corrections
Use the timeline and playback controls along the bottom of the IK Retargeter Editor window to play, pause, and scrub the animation. Move the camera around the Viewport to identify potential issues, such as clipping and awkward limb positioning.
In the example above, you can see that the MetaHuman's arms are positioned at a higher angle than would be natural. To solve this, follow the steps below:
In the Chain Mapping panel, click the LeftArm chain.
In the LeftArm chain's Details panel, in the IK section, set the Z value of the Static Offset option to
-10
.Every animation has different offset requirements. Experiment by changing offset values and replaying the animation until you find the values that work best.
Repeat these steps for the RightArm chain.
Export the Retargeted Animation
Once you’re happy with how your animation looks, click Export Selected Animations to export your animation.
This will create a new Animation Asset targeted to the MetaHuman Skeleton. Select the location where you want to save the new Asset, then click OK.
You can now close the IK Retargeter Editor window.
Configure the Retargeted Animation Asset
In the Content Browser, locate the retargeted Animation Asset and double-click it to open it in the Animation Editor.
Make sure that the Retarget Source Asset (1) and Preview Mesh (Animation) (2) properties highlighted in the screenshot below are set to your MetaHuman’s Skeletal Mesh:
After you configure these properties, Save the Animation Asset and close this window.
Final Result
You now have an Animation Asset targeted to your MetaHuman’s Skeleton that works with their specific body height and body type. You can quickly test your animation by assigning it to your MetaHuman’s Body component in the BP_(MetaHumanName)
Blueprint. The final result is shown below.