How to Retarget Mixamo Animations to Metahuman in Unreal Engine Using the IK Retargeter

Mixamo offers a large library of character animations, while MetaHumans in Unreal Engine 5 (UE5) provide realistic digital humans. You can apply Mixamo animations to MetaHuman characters in UE5 using the IK Retargeter system. This guide details retargeting Mixamo animations to a MetaHuman, covering exporting from Mixamo, setting up IK rigs, mapping bones, fixing issues like foot sliding, and adding facial animation and custom hair. This enables quick use of Mixamo motions for MetaHuman characters in games, cinematics, or other projects.

Can you use Mixamo animations with MetaHuman characters in Unreal Engine 5?

Yes, Mixamo animations can be retargeted to MetaHuman characters in UE5 using the IK Rig and IK Retargeter tools, which simplify transferring animations between skeletons with different bone names or proportions. Mixamo’s humanoid rig animations map easily to the MetaHuman skeleton via UE5’s standard workflow, unlike the more manual process in UE4. With proper setup, Mixamo’s free animations can animate MetaHumans efficiently.

What is the IK Retargeter in Unreal Engine 5 and how does it work?

The IK Retargeter in Unreal Engine 5 enables advanced animation retargeting between different skeletons using inverse kinematics (IK) to maintain natural contacts like foot placement. Unlike the old system requiring identical hierarchies, it uses IK Rig assets and bone chain mapping.

• Process:
  • Create IK Rig assets for source (e.g., Mixamo) and target (e.g., MetaHuman) skeletons.
  • Define Retarget Chains (e.g., “Arm chain,” “Leg chain”) in each IK Rig for limbs/body parts.
  • Create an IK Retargeter asset, select source IK Rig, assign target IK Rig, and map chains (e.g., Mixamo arm to MetaHuman arm).
  • Adjust Retarget Pose in the editor to align rest poses, preview animations, and let IK dynamically retarget bones.
• Benefits:
  • Works with differing bone names/counts.
  • Uses IK to reduce issues like foot sliding or knee popping.
  • Transfers animations (e.g., Mixamo to MetaHuman) effectively.

Upcoming sections will guide beginners through creating IK Rigs and using the Retargeter.

How do I export Mixamo FBX files for clean import into Unreal Engine?

Exporting Mixamo Animations for Unreal Engine 5

1. Choose a Character: Select one Mixamo character (e.g., Y-Bot) for all animations to ensure consistent skeleton hierarchy and scale.
2. Select and Tweak Animation: Pick an animation, adjust sliders (e.g., arm spacing, speed), and verify it looks correct on the character.
3. Download Settings:
   • Set Format to FBX (FBX Binary or “FBX for Unreal Engine” if available).
   • Use “With Skin” for the first export (character + skeleton, e.g., T-pose); use “Without Skin” for subsequent animations (skeleton data only).
4. Download FBX: Save the file; it includes animation (and mesh if with skin). Use one character (e.g., “Passive Marker Man” recommended for better retargeting) for simplicity.

Importing Mixamo Animations into Unreal Engine 5

1. Import Character and Skeleton:
   • Import the “with skin” FBX (e.g., T-pose) via Content Browser > Import.
   • In FBX Import Options: Check “Import Skeletal Mesh,” uncheck “Import Animations,” set “Skeleton” to “None” (creates new skeleton asset).
   • Result: Skeletal Mesh and Skeleton asset (e.g., Mixamo bones: hips, spine).
2. Import Animation FBX (Without Skin):
   • Import an animation FBX via Content Browser.
   • In FBX Import Options: Check “Import Animations,” set “Skeleton” to the skeleton from step 1.
   • Result: Animation Sequence linked to the skeleton.
3. Repeat for Additional Animations: Import all animations using the same skeleton to avoid multiple skeletons.

This ensures one skeleton for all animations, preventing errors like “root track” mismatches (Mixamo uses Hips as top bone, no root). After import, you’ll have a skeleton asset, animation sequences, and optionally the skeletal mesh, ready for retargeting in UE5.

Do I need to fix the Mixamo skeleton before using it with Metahuman?

Modifying a Mixamo skeleton before retargeting to a MetaHuman isn’t usually necessary—UE5’s IK Retargeter can manage—but minor tweaks improve results:

• Root Bone: Mixamo lacks a root bone (Hip is top); MetaHumans have one (“root”). For root motion (e.g., walking), add a root bone to Mixamo and recalculate animations, or skip if using in-place animations.
• Retarget Root Setting: In UE5 IK Rig, set Mixamo’s pelvis as the retarget root and MetaHuman’s “root” similarly to align them, avoiding physical bone addition.
• A-Pose vs T-Pose: MetaHumans use A-pose; some Mixamo rigs (e.g., Y-Bot) use T-pose. Adjust the Retarget Pose in UE5’s IK Retargeter to match poses (e.g., tweak Mixamo to A-pose), no external rigging needed.
• Bone Orientation/Naming: No renaming required; UE5 maps chains despite differing names/orientations. Pose adjustments handle discrepancies.
• Twist Bones: MetaHuman has twist/metacarpal bones Mixamo lacks. Exclude these from chain mapping to avoid issues like “exploded” hands.

Summary: Use IK Retargeter to mark roots, align poses, and skip non-matching bones for smooth retargeting.

How do I set up a source and target rig for Mixamo to MetaHuman retargeting?

Create IK Rig assets in UE5 for Mixamo and MetaHuman skeletons to define bone chains:

1. Mixamo IK Rig (Source):
   • In Content Browser, right-click Mixamo skeleton → Animation > IK Rig, name it “IK_Rig_Mixamo.”
   • Open IK Rig Editor, add Retarget Chains:
     • Spine: lowest spine to neck.
     • Head: neck to head.
     • Arm_L: LeftShoulder to LeftHand.
     • Arm_R: right side equivalent.
     • Leg_L: left thigh to foot/toe.
     • Leg_R: right side equivalent.
     • Fingers: optional, group hand or per finger.
   • Exclude twist bones Mixamo lacks.
   • Optional IK Goals: add at hands/feet for precision.
2. MetaHuman IK Rig (Target):
   • From MetaHuman skeleton (e.g., metahuman_base_skel), create “IK_Rig_MetaHuman.”
   • Define matching chains:
     • Spine: pelvis to neck_01.
     • Head: neck_01 to head.
     • Arm_L: clavicle_l to hand_l.
     • Leg_L: thigh_l to foot_l/toe_l.
     • Fingers: optional, simpler than MetaHuman’s.
   • Skip twist bones (e.g., lowerarm_twist).
   • Add IK Goals if used in source (hands/feet).

Save both IK Rigs with corresponding chain names (e.g., “Arm_L”) for easy mapping in the retargeter.

What is the correct bone mapping for Mixamo to Metahuman in UE5?

With IK Rigs set up, chain mapping in the IK Retargeter pairs corresponding chains between Mixamo and MetaHuman rigs. Bone equivalences are:

• Root/Pelvis: Mixamo “Hips” maps to MetaHuman “Pelvis” (or “root” in spine/root chain).
• Spine: Mixamo (Spine, Spine1, Spine2, Neck, Head) maps to MetaHuman (spine_01, spine_02, spine_03, neck_01, head).
• Arms: Mixamo (LeftShoulder, LeftArm, LeftForeArm, LeftHand) maps to MetaHuman (clavicle_l, upperarm_l, lowerarm_l, hand_l); same for right side.
• Legs: Mixamo (LeftUpLeg, LeftLeg, LeftFoot, LeftToeBase) maps to MetaHuman (thigh_l, calf_l, foot_l, ball_l/toe_l); toe optional.
• Hands/Fingers: Mixamo (e.g., LeftHandIndex1,2,3) maps to MetaHuman (e.g., index_proximal_l, intermediate_l, distal_l); chain per finger optional.

Chain mapping simplifies this (e.g., “Arm_L” chain covers shoulder to hand). In the IK Retargeter’s Chain Mapping section, assign Target chains to Source chains (auto-matched if named identically). Tips:

• Map only meaningful chains; MetaHuman twist bones stay unmapped.
• Root chain (Hips to Pelvis) handles positioning; pelvis often set as retarget root.
• Map IK Goals (e.g., “LeftHandIK”) for accurate end effectors like foot planting.

Mapping aligns body parts: Hips -> Pelvis, Spine -> Spine, etc. The UE5 IK Retargeter adapts differing bone names if chains are correct.

How to Retarget Mixamo Animations to MetaHuman Using IK Retargeter

1. Create IK Retargeter: In Content Browser, Add > Animation > IK Rig > IK Retargeter; select Mixamo IK Rig as source, name it (e.g., “RTG_Mixamo_to_MetaHuman”).
2. Open Retargeter: Double-click asset; set MetaHuman IK Rig as target, view both skeletons.
3. Chain Mapping: Match Target chains (MetaHuman) to Source chains (Mixamo) in Chain Mapping section (e.g., “Arm_L” to “Arm_L”).
4. Retarget Pose: Adjust source (Mixamo) or target (MetaHuman) pose (e.g., T-pose to A-pose) for alignment; save/import poses if needed.
5. Preview Animation: In Asset Browser, select a Mixamo animation; MetaHuman mirrors it. Check feet, arms, scale; tweak Global Settings (e.g., Stride Warping) if off.
6. Export Animation:
   • Method A: In Retargeter, right-click animation > “Export Selected Animation”; save as new asset (e.g., “Mixamo_Walk_MetaHuman”).
   • Method B: In Content Browser, right-click Mixamo animation > “Retarget Animation Assets > Duplicate and Retarget”; select MetaHuman skeleton and Retargeter.
7. Apply Animation: Assign new animation to MetaHuman’s Skeletal Mesh (via Animation Blueprint or direct play) for testing.

Iterate by adjusting pose, chain settings, or IK options (e.g., root scaling, foot planting) until correct.

How do I retarget multiple Mixamo animations to a single Metahuman asset?

Unreal Engine’s batch retargeting simplifies retargeting multiple animations:

• Batch Retarget via Content Browser: Select multiple Mixamo animations, right-click, choose “Retarget Animation Assets > Duplicate and Retarget Animation Assets…”:
  • Select IK Retargeter Asset (e.g., RTG_Mixamo_to_MetaHuman).
  • Set Target Skeleton (MetaHuman’s skeleton, may auto-fill).
  • Preview source/target meshes.
  • Add prefix/suffix (e.g., “_MH”) for new asset names.
  • Verify animations listed, click Retarget to process.
• Result: New MetaHuman skeleton animations created; organize in a folder (e.g., Content/MetaHuman/Animations/RetargetedFromMixamo).
• Alternative: Use IK Retargeter UI for manual retargeting (suitable for few animations; batch better for many).
• Consistency: Same pose/chain settings apply; adjust for unique animations (e.g., crouching) if needed.

Can I use custom poses in the IK Retargeter to improve Mixamo-to-Metahuman accuracy?

Yes, custom poses enhance retargeting:

• Scenarios:
  • Idle Stances: Match crouching Mixamo to MetaHuman crouch pose to fix sliding.
  • Hand Placement: Adjust pose for object interaction (e.g., hand on hip) to avoid penetration.
  • Bone Lengths: Tweak pose (e.g., bent knees) to offset proportion differences, reducing foot sliding.
  • Pose Library: Save poses (A-pose, crouch) for reuse.
• Process:
  • In IK Retargeter, select Edit Retarget Pose, adjust bones.
  • Save pose within asset or externally.
  • Apply per animation if needed (preview tweaks, re-apply for export).
• Common Fix: Align Mixamo T-pose arms with MetaHuman’s lower pose to correct shoulder/arm issues.
• Outcome: Custom poses improve accuracy, from basic A/T alignment to action-specific adjustments.

What are common issues when retargeting Mixamo to Metahuman and how do I fix them?

The IK Retargeter can have quirks when retargeting animations to MetaHumans. Here’s a summary of common issues and fixes:

• Misaligned limbs/offsets: Check and tweak the retarget base pose to align skeletons in a neutral stance.
• Twisted/deformed wrists/arms: Set twist bones to copy parent rotations or exclude them from IK mapping in the skeleton asset or IK Rig.
• Foot sliding:
  • Enable Stride Warping or IK foot stabilization.
  • Use root motion if available, or adjust pelvis motion.
  • Tweak character movement speed to match animation.
• Character floating/sinking: Adjust Retarget Root settings and root bone translation scaling.
• Head/neck issues: Include neck/head in chain mapping, exclude end bones like “head_end.”
• Jittery/distorted animation: Resample animation to 30fps or 60fps, disable “Allow Frame Stripping.”
• Clothing/hair not following: Tune physics settings, not a retarget issue.

Most problems stem from pose or bone mismatches. Use bone debugging in the retargeter to verify mappings and iterate adjustments.

How do I retarget Mixamo walk cycles to MetaHuman without foot sliding?

Foot sliding occurs when feet don’t stay planted during strides. Fixes include:

• Root Motion: Add a root bone to Mixamo animations (e.g., via Blender or UE5 plugins), enable Root Motion in UE5, and map it in the retargeter.
• Stride Warping: Enable in IK Retargeter to adjust leg motion for proper foot placement.
• Adjust play rate/distance: Sync character speed with animation cycle distance to avoid mismatches.
• Foot IK in AnimBP: Use Two-Bone IK or FullBody IK to pin feet to the ground.
• Proper Retarget Root: Set pelvis as source root and MetaHuman root as target for basic motion compensation.

For best results, use root motion if you can add it to Mixamo animations; otherwise, combine stride warping and speed tweaks.

Can I blend Mixamo animations with other animation layers on a Metahuman?

Retargeted Mixamo animations on a MetaHuman function like regular animations, allowing blending and layering in Unreal Engine via Animation Blueprints or montages. Here’s how:

• Animation Blueprints – Layered Blend per Bone: Blend two animations (e.g., Mixamo run cycle for legs, shooting animation for upper body) using the Layered blend per bone node.
• Animation Montages: Slot Mixamo animations into montages (e.g., idle lower body, wave upper body) using slots like DefaultGroup.UpperBody.
• Aim Offsets / Look At: Add aiming or looking around to Mixamo animations with Aim Offset or LookAt nodes.
• Modify Bone / Control Rig: Adjust bones (e.g., hand for a weapon) procedurally on top of Mixamo animations using Control Rig.
• Facial Animations Separate: MetaHumans split facial (Face AnimBP) and body (Body AnimBP) animations, allowing independent face animation over Mixamo body motion.

Retargeted Mixamo animations integrate with Unreal’s animation system, enabling state machines, speed blends, or layered upper-body twists.

How do I add facial animation to Mixamo-driven MetaHuman motion?

Mixamo animations lack facial movement, leaving MetaHuman faces static by default. To add facial animation:

• Live Capture: Use Live Link (e.g., iPhone app) or MetaHuman Animator to record/stream facial performances while the body plays Mixamo animations.
• Pre-made Animations: Apply existing facial clips or keyframe lip-sync (via ARKit-compatible tools or Control Rig) alongside Mixamo body animations.
• Control Rig in Sequencer: Keyframe facial expressions in Sequencer over Mixamo body animations for cinematics.
• Head Bone Check: Ensure the face mesh follows head movements (default in MetaHuman blueprints).
• Sequencer Blend: Combine Mixamo body animation and separate facial tracks in Sequencer for cutscenes.

The MetaHuman blueprint merges body and face animations at runtime, offering flexibility to craft facial performances independently using tools like Live Link or MetaHuman Animator.

How do I export Mixamo FBX files for clean import into Unreal Engine?

When exporting from Mixamo for Unreal:

• Format: Use FBX (FBX Binary), or FBX for Unreal Engine if available for better compatibility (correct axis and scale).
• Skin option: Export “Without Skin” for animation files (skeleton only), “With Skin” for the base character (skeleton and mesh).
• Consistent character: Use the same character for all animation exports to share the skeleton structure.
• Keyframe reduction: Mixamo bakes keys on every frame, making files larger; UE can handle it, or reduce keys in-engine.
• Import: Import character FBX first (with skin, no anim), then animations (no skin) onto that skeleton.

In summary, export with FBX, use “Without Skin” for animations, ensuring a clean UE5 import.

Is it possible to use Unreal’s Control Rig on Mixamo animations for cleanup?

Yes, UE5’s Control Rig can tweak retargeted animations in-engine, ideal for fixing issues.

For a MetaHuman animation from Mixamo:

• MetaHuman Control Rig: Use the provided MetaHuman_ControlRig for body adjustments.
• Bake animation: In the Animation Sequence editor or Sequencer, bake the animation to the Control Rig for editable keyframes.
• Edit: Adjust poses (e.g., fix foot placement with IK or hand clipping with arm controls) and set keys.
• Bake back: Save edits as a new animation sequence asset via Bake Animation Sequence.

For minor fixes, adjust retarget poses; for detailed edits, Control Rig is best. Works similarly for non-MetaHuman skeletons (e.g., UE5 mannequin).

Example use cases:

• Fix foot sliding by planting the foot controller.
• Adjust gesture timing to match voiceover.
• Add secondary motion (e.g., head turn, arm sway).
• Correct unnatural poses (e.g., odd elbow bends).

Control Rig offers non-destructive edits in Unreal, avoiding external re-imports, saving time.

How can PixelHair be used to give custom hair styles to Metahuman characters animated with Mixamo and IK Retargeter?

PixelHair provides 3D hair groom files (often from Blender) usable as Groom assets in Unreal Engine, allowing custom hairstyles (e.g., braids) for MetaHumans beyond default presets. These work seamlessly with retargeted animations.

Here’s how to use PixelHair with a MetaHuman:

• Import the PixelHair groom asset into Unreal and add it as a Groom component in the MetaHuman Blueprint.
• Attach it to the “head” bone, adjusting position, rotation, and scale to fit.
• The hair follows head movements during Mixamo animations, with optional Chaos physics for simulation.
• Swap multiple PixelHair styles without affecting animations, enhancing visual customization.
• For complex grooms, tweak physics to avoid clipping during heavy movement.

PixelHair is animation-independent, functioning like standard MetaHuman hair grooms.

Can I use root motion when retargeting Mixamo animations to MetaHuman?

Mixamo animations lack a root bone (starting at the hips), requiring extra steps for root motion in Unreal, where MetaHuman skeletons have a root.

How to enable root motion from Mixamo animations:

1. Add a Root Bone: In Blender, add a “root” bone above “Hips,” bake animation to transfer movement, and export as FBX. Alternatively, use a UE5 plugin (e.g., Mixamo Converter) to add a root in Unreal.
2. Mark Retarget Roots: In IK Rigs, set the new “root” as the source retarget root and MetaHuman’s “root” as the target.
3. Retarget with Root Motion: The root bone’s motion transfers to MetaHuman.
4. Enable Root Motion: In the retargeted animation asset, set “Enable Root Motion” and “Root Motion from Everything.”
5. Use in AnimBP: Enable “Root Motion” in the AnimBlueprint settings.

Alternatives without a root bone:

• Retarget without a root for in-place animations, moving the character manually.
• Use the pelvis as the retarget root to simulate root motion (less reliable).
• Apply Stride Warping for foot adjustments with in-place animations.

Root motion ensures precise movement (e.g., no foot sliding) and suits cinematics or AI, while in-place animations with CharacterMovement fit player-controlled MetaHumans. Preparation enables the IK Retargeter to handle root motion effectively.

What’s the difference between the old retargeting system and the UE5 IK Retargeter?

Unreal Engine’s old retargeting system (UE4, still in UE5 as “Anim Retarget”) differs from the new IK Retargeter in UE5. Key differences include:

• Bone vs. Chain Mapping: Old system maps bones individually, requiring similar structures; IK Retargeter uses flexible chain mapping, allowing retargeting between varied skeletons (e.g., 3-spine to 5-spine).
• Bone Flexibility: Old system struggles with extra bones (e.g., MetaHuman twist bones stay static); IK Retargeter ignores unmapped bones, reducing issues.
• IK Adjustments: IK Retargeter uses IK goals and Stride Warping for precise foot/hand placement; old system maps rotations, often causing floating feet.
• Retarget Poses: Old system requires manual base pose setup; IK Retargeter integrates visual, adjustable poses.
• Preview: IK Retargeter offers real-time side-by-side previews; old system lacks robust preview.
• Skeleton Types: Old system is humanoid-focused; IK Retargeter supports any skeleton via custom chains.
• Runtime: IK Retargeter enables runtime retargeting; old system is editor-only.
• Quality: IK Retargeter delivers better results with less tweaking.

For Mixamo to MetaHuman, IK Retargeter is superior, offering one-step retargeting vs. the old two-step process.

How do I organize and reuse retargeted Mixamo animations across MetaHuman projects?

• Folder Structure: Store in a dedicated folder (e.g., Content/Animations/MetaHumanMixamo/), subfolder by type (locomotion, dances).
• Naming: Use clear names (e.g., “StandingJump_MH”).
• Skeleton Reuse: MetaHumans with the same skeleton (e.g., metahuman_base_skel) share animations; one retarget works for all matching skeletons.
• AnimBP Sharing: Create a reusable Animation Blueprint with state machines for MetaHumans of the same skeleton.
• Migration: Use Asset Migration to transfer animations and skeletons to new projects; recreate MetaHumans to ensure skeleton compatibility.
• Version Control: Store original Mixamo FBXs outside UE for re-importing.
• Documentation: Track original-to-retargeted animation mappings.
• Sharing: Respect Mixamo’s license; animations are reusable across team projects.

Retargeted animations are highly reusable across MetaHumans with the same skeleton, enhancing efficiency.

Where can I find free Mixamo animations to test with Metahuman characters?

Mixamo is a free online animation repository requiring an Adobe account, offering thousands of animations (e.g., walking, dancing, fighting) for download and commercial use.

Steps to Get Animations:

• Visit mixamo.com, sign in, go to Animations tab, browse/search (e.g., “walk”, “jump”), preview, and download (e.g., FBX).

Other Free Animation Sources:

• ActorCore by Reallusion: Free mocap animations, requires signup, may need retargeting.
• Unreal Engine Marketplace: Free packs (e.g., Animation Starter Pack), retargetable to MetaHuman from UE4 mannequin.
• CMU Mocap Library: Large free dataset, needs conversion for UE4 mannequin, then retargetable to MetaHuman.
• Mixamo Community Uploads: Repackaged Mixamo animations, legal for use but not redistribution; download directly from Mixamo for safety.

Suggested Mixamo Downloads for Testing:

• “Idle”, “Walking”, “Running” for locomotion.
• “Robot Dance” or “Hip Hop Dance” for full-body motion.
• “Jump” and “Punch” for quick actions.

Mixamo’s free animations, usable in commercial projects, are ideal for MetaHuman prototyping. Check Unreal Marketplace and other mocap libraries for additional options.

Are there tutorials for using Mixamo, MetaHuman, and the IK Retargeter together in UE5?

Yes, tutorials abound:

• Epic Games Resources: Documentation and community tutorials (e.g., “Animation Retargeting in UE: From Mixamo to MetaHuman”) cover IK rigs and retargeting.
• YouTube Videos: Titles like “Unreal Engine 5 Mixamo to MetaHuman | IK Rig Tutorial”, “Retarget Mixamo Animations to MetaHuman | Unreal Engine 5 Tutorial”, and “FAST MetaHuman Retargeting in UE5 (IK Rig)” detail the process.
• Community Guides: Reddit, blogs (e.g., 80.lv, Medium) offer written steps and tips.
• Mixamo Plugin Docs (UNAmedia): Provides troubleshooting and video support.
• MetaHuman Docs: Explains retargeting UE4 mannequin animations to MetaHuman, applicable to Mixamo.
• Blender Tutorials: Cover adding root bones to Mixamo animations for Unreal.

Focus on UE5 IK Rig/IK Retargeter tutorials. Epic’s learning portal, forums, and AnswerHub complement video and written guides for comprehensive learning.

Frequently Asked Questions (FAQ)

• Do I need a special plugin or tool to retarget Mixamo animations to MetaHumans?
  No, Unreal Engine 5’s built-in IK Retargeter works fine. Optional plugins like Mixamo Animation Retargeting addon can simplify steps but aren’t required.
• Can I use Mixamo animations in Unreal Engine 4 with MetaHumans?
  MetaHumans are UE5-focused. In UE4, retarget Mixamo animations to the UE4 mannequin, then shift to UE5 for direct MetaHuman retargeting.
• Are Mixamo animations free for commercial use?
  Yes, with a free Adobe account, they’re usable in commercial projects like games or films, but raw animation files can’t be resold.
• Do all Mixamo characters use the same skeleton?
  Yes, Mixamo auto-rigged characters share a bone hierarchy, so one IK Rig works for all Mixamo animations.
• My retargeted MetaHuman’s limbs look twisted – what’s wrong?
  Check pose alignment (A-pose vs T-pose) and exclude mismatched bones (e.g., MetaHuman twist bones) in IK mapping to fix distortions.
• Should I adjust the character pose before retargeting?
  Yes, align source (Mixamo) and target (MetaHuman) rest poses (e.g., A-pose or T-pose) in the IK Retargeter for better results.
• Can I retarget animations to any MetaHuman regardless of body type or gender?
  Yes, if they share the same skeleton asset. Different skeletons (e.g., tall male vs short female) need separate retargeting, but adjustments handle minor variations.
• Is there a recommended Mixamo character for better retargeting?
  Passive Marker Man is suggested for its simple rig, reducing issues, though any Mixamo rig works with proper setup.
• How can I prevent foot sliding without root motion?
  Use UE5’s Stride Warping and IK foot planting in the IK Retargeter or AnimBlueprint, and match character speed to animation pace.
• Do I need a new IK Rig for every Mixamo animation?
  No, one IK Rig per skeleton (Mixamo and MetaHuman) and one IK Retargeter setup work for all animations of that pair.

Conclusion

Retargeting Mixamo animations to MetaHumans in Unreal Engine 5 leverages UE5’s IK Rig and IK Retargeter for an efficient workflow. Here’s the process:

• Export from Mixamo: Download animations (FBX, no skin) and a base character (FBX, with skin) using consistent settings.
• Import into Unreal: Import the Mixamo character and animations, linking them to the same skeleton asset.
• Set up IK Rigs: Create IK Rigs for both Mixamo and MetaHuman skeletons, defining matching bone chains (arms, legs, spine).
• Adjust Skeleton Differences: Set retarget roots and align poses (e.g., T-pose vs. A-pose) using the retarget pose feature.
• Create IK Retargeter: Link the Mixamo IK Rig (source) to the MetaHuman IK Rig (target) and map chains.
• Preview and Refine: Test animations in the retargeter preview, adjusting poses, chains, or IK settings (e.g., stride warping) to fix issues like foot sliding.
• Export Animations: Export retargeted animations as new assets for the MetaHuman skeleton.
• Apply to MetaHuman: Use these in the MetaHuman’s animation blueprint or Sequencer.
• Enhance: Add MetaHuman facial animations or polish with Control Rig.

This addresses pitfalls like foot sliding (via root motion/IK), twist issues (via chain mapping), and pose mismatches (via retarget poses). Organized retargeted animations create a reusable library, enabling rapid prototyping of MetaHumans with Mixamo motions (run, jump, dance) without motion capture or manual keyframing. This pipeline merges MetaHuman fidelity with Mixamo’s motion library for efficient, high-quality animation workflows.

Sources

• Unreal Engine Documentation – IK Rig and IK Retargeting in UE5 (explains the IK retarget system and settings)​​docs.unrealengine.com.
• Epic Dev Community Tutorial – Animation Retargeting in UE: From Mixamo to MetaHuman (community guide demonstrating IK Rig setup for Mixamo and MetaHuman)​dev.epicgames.com.
• UNAmedia Plugin Documentation – Mixamo Animation Retargeting 2 for UE5 (documentation and steps for retargeting Mixamo animations, with and without the plugin)​unamedia.com.
• Unreal Engine Forums – Community Q&A threads on retargeting issues (e.g., solving twisted limbs, head issues, etc.)​​forums.unrealengine.com.
• Kalponic Studio Blog – Mixamo Root Motion in Unreal Engine 5 (tutorial on adding a root bone to Mixamo animations and enabling root motion in UE5)​​kalponicstudio.com.
• Adobe Mixamo Documentation – Mixamo usage and license info (clarifies that Mixamo content is free to Adobe account holders for use in projects)​community.adobe.com.
• Yelzkizi PixelHair Tutorial – Using PixelHair with MetaHumans in UE5 (guide on attaching PixelHair groom assets to MetaHuman characters)​yelzkizi.org.
• GameDev Stack Exchange – Q&A confirming Mixamo characters share the same skeleton structure (facilitating animation reuse)​gamedev.stackexchange.com.
• Unreal Engine Documentation (MetaHumans) – Retargeting Animations to a MetaHuman (explains sharing animations via same skeleton assets and retargeting from other sources)​dev.epicgames.com.
• Various Unreal Engine 5 YouTube Tutorials – (Maris Freimanis, Design Studio Press, and others) covering Mixamo to MetaHuman retargeting with IK Rig, which complement the above written resources​youtube.com​dev.epicgames.com.

Recommended

• PixelHair vs. Manual Hair Grooming in Blender: Which is Better?
• Redefining Representation: Authentic Black Hairstyles in Video Games
• How Do I Track an Object With a Camera in Blender?
• How do I make the camera follow a character in Blender?
• Your Guide to Making 3D Models for 3D Printing
• How to Get the Perfect Hair Roughness for a Realistic Look
• How to Create Realistic Hair Clumping in Blender: A Step-by-Step Guide
• Unreal Engine vs Unity: Which Game Engine Is Best for Your Project?
• Understanding Interpolate Hair Curves geometry nodes preset
• How to Add Texture to a 3D Model in Blender: A Step-by-Step Guide to Creating Stunning Materials