motionsmith-docs-v2
MotionSmith Pro V2 Docs
Technical reference for MotionSmith Pro V2 in Unreal Engine 5.8: Gameplay Motion, Sequencer-native segment generation, route following, Kimodo fallback, Control Rig preparation, supported characters, and grounding requirements.
What V2 changes
MotionSmith Pro V2 moves animation direction into Unreal Engine Sequencer. Instead of treating AI animation as a separate generation step, V2 builds and extends character performance as editable Sequencer segments inside the shot.
Watch the Pro V2 Overview
Prepared motion first
Common locomotion and gameplay intents can resolve to prepared animation assets before generation is required.
Generate when needed
Instructions that cannot be satisfied by the prepared motion library can fall back to Kimodo generation.
Shot-level iteration
Segments remain in the same sequence as cameras, lights, props and timing decisions.
Refine after generation
Supported characters can be prepared for Control Rig so broad generated motion can be polished in context.
Project requirements
| Area | Requirement |
|---|---|
| Engine | Unreal Engine 5.8 |
| Platform | Windows 64-bit (Win64) editor |
| GPU | NVIDIA GPU with CUDA. 6 GB. Recommended: 16 GB VRAM (tested on GeForce RTX 5070 Ti 16 GB). By default the Llama 3 text encoder runs on the CPU, so the GPU runs only the Kimodo diffusion model. |
| System memory | 8 GB. 32 GB or more recommended. The Llama 3 8B text encoder (about 16 GB) is loaded into system memory by default. |
| Disk space | About 25 GB free: MotionSmith Runtime and models (about 5 GB) and Meta Llama 3 8B Instruct (about 20 GB) |
| MotionSmith Runtime | Separate local download: MotionSmith Runtime on Hugging Face |
| Meta Llama 3 | Meta-Llama-3-8B-Instruct, downloaded by the user from Hugging Face under the Meta Llama 3 Community License |
| Gameplay Motion content | Epic's Game Animation Sample (UE 5.8). Keep
/Game/Characters/UEFN_Mannequin at its original path.
|
| Engine plugins | IK Rig, Control Rig, RigVM, Chooser, Level Sequence Editor, Motion Warping (Beta), Sequencer Mixed Control Rig (Experimental) |
| Supported Character Paths | UE5 Manny / Quinn, MetaHumans from the UE 5.8 pipeline, AccuRig, Mixamo and Character Creator skeletons. See Supported Characters. |
| Gameplay Motion Ground | Traversable floor geometry must have valid collision that matches the visible walkable surface |
| Control Rig | Sequencer Mixed Control Rig plugin (Experimental) is required for the mixed Control Rig workflow |
Bad Simple or Convex collision can be interpreted as an obstacle even when the visible mesh looks clear. Use collision that accurately follows the walkable surface. For Static Mesh floors, use appropriate Simple Collision or
Use Complex Collision As Simple when necessary.
The prepared motion library is built on the UE 5.8 Game Animation Sample animations under
/Game/Characters/UEFN_Mannequin/Animations. These animations are not included in MotionSmith.
Create your project from the Game Animation Sample, or migrate its Characters folder without
moving or renaming it.
Kimodo prompt generation does not require it.
Generation runs in a local MotionSmith Runtime process that talks to Unreal Editor directly. MotionSmith does not upload your prompts, animations or usage data, and it does not download models automatically.
From Fab to your first shot.
Install MotionSmith Pro V2 for Unreal Engine 5.8, complete the project setup, verify the local runtime, and prepare your project for Sequencer-native motion.
Install from Fab
Add MotionSmith Pro V2 to your Fab Library, then use Install to Engine and select Unreal Engine 5.8.
Enable MotionSmith
Open your project and go to Edit → Plugins. Find MotionSmith Pro V2, enable it, then restart Unreal Editor when prompted.
Configure Project Settings
Go to Edit → Project Settings → Plugins → MotionSmith Pro.
MotionSmith needs Meta-Llama-3-8B-Instruct and does not download it for you:
request access on its
Hugging Face page
by accepting the Meta Llama 3 Community License, then download it once access is approved,
for example with hf auth login and
hf download meta-llama/Meta-Llama-3-8B-Instruct --exclude "original/*".
A model in the default Hugging Face cache is found automatically; otherwise set
Llama Model Folder to the folder that contains config.json,
the tokenizer files and the .safetensors weights.
Verify Runtime & Pre-Flight
Check that the MotionSmith Runtime, Python environment, NVIDIA GPU / CUDA, Kimodo, LLM2Vec adapters, Meta Llama and backend setup are detected correctly. Click Run Pre-Flight in the Diagnostics & Pre-Flight section and resolve any failed required checks before generation. Download the runtime from Hugging Face, also reachable from the Download Runtime button in Project Settings.
Enable the animation workflow
Verify that Sequencer Mixed Control Rig is enabled. For Manny / Quinn Control Rig workflows, the required CR_Mannequin_Body asset must be available in the project; MotionSmith does not bundle that Control Rig asset. MotionSmith also enables its engine plugin dependencies, including Motion Warping (Beta) and Sequencer Mixed Control Rig (Experimental). For Gameplay Motion, use a project based on the Game Animation Sample.
Prepare your character
Add a supported character to a Level Sequence, select the intended character binding, then use Prepare Character so MotionSmith can create or reuse the required Sequencer animation and Control Rig setup.
Open Sequencer and create
Open MotionSmith Pro V2 and work directly in the shot using Gameplay Motion, prompt generation, continuation and Control Rig refinement.
Basic V2 workflow
Add the character to Sequencer
Use a supported character and make sure the expected skeletal mesh and sequence binding are active.
Create or edit the route
In the Gameplay Motion panel, click Align to Character to create a route at the character, facing its forward direction. Click Select Route and move the route's spline points in the viewport. The route defines XY direction; grounded motion resolves against the physical scene.
Enter the motion instruction
Use a direct action such as walk, run, turn, jump, crouch, vault, or a more specific performance prompt.
Generate and commit
MotionSmith resolves the instruction through Gameplay Motion or Kimodo and commits the result as Sequencer sections.
Extend instead of rebuilding
Extend the route and add the next motion instruction. Previously committed sections remain unchanged.
Prepared gameplay motion inside the route
Gameplay Motion is the fast path for common actions. The system analyzes the instruction and available route context, resolves suitable prepared clips, adapts them to the current character and places them in Sequencer.
Gameplay Motion panel
Typical grounded actions
- Idle
- Walk
- Run
- Sprint
- Left / right turns
- Grounded continuation after a turn
Route & Grounding
Grounded movement uses the user-authored route for XY direction and the resolved ground path for vertical placement. This allows motion to follow ramps and other traversable changes in elevation.
XY = user-authored route Z = resolved traversable ground Yaw = route tangent / motion facing Result = grounded character motion along the shot
Continuation
V2 is designed around append-only continuation. After a committed segment, extending the route and generating a new instruction appends only the new tail of the performance.
- Previous committed sections stay unchanged.
- The next segment starts from the evaluated exit of the previous section.
- Route extension can continue beyond the original path length.
Gameplay Animation System + Kimodo
MotionSmith GAS means Gameplay Animation System — not Unreal Engine's Gameplay Ability System. It is the prepared Gameplay Motion path used for predictable locomotion and supported actions. MotionSmith can combine GAS assets and Kimodo-generated motion in the same Sequencer performance. Its prepared animation library comes from Epic's Game Animation Sample (UE 5.8), which must be present in the project; see Requirements.
Use when a prepared solution exists
Best for common locomotion, turns and known gameplay actions where predictable motion is preferred.
Use for open-ended instructions
Used when the action cannot be resolved from the prepared motion library and generation is required.
Kimodo Generation panel
Strong generation intents
Prompts such as jump, jump down, jump forward,
vault, climb and crouch are treated as strong action intents.
MotionSmith first attempts the prepared Gameplay Motion path and can fall back to Kimodo when necessary.
How V2 uses Sequencer
V2 does not treat Sequencer as an export target. Sequencer is the primary workspace. Motion sections are inserted into the existing sequence so timing, cameras, props, animation layers and shot context remain visible throughout the process.
- Generated sections remain editable.
- Gameplay Motion and Kimodo-generated sections can coexist.
- Continuation appends new sections instead of rebuilding earlier work.
- Camera and prop context remain visible during animation direction.
- Motion generation and baking controls are available directly from the Sequencer workflow.
MotionSmith Sequencer Bar
MotionSmith adds a dedicated control bar to Sequencer so the most frequently used animation operations remain available while working directly inside the shot. The bar provides access to segment timing, motion generation, continuation, baking and local backend control without leaving Sequencer.
| Control | Purpose |
|---|---|
| Duration | Defines the intended duration of the current motion segment before generation. |
| Add Segment | Adds a new motion segment after the existing performance so the sequence can be extended without rebuilding previously committed animation. |
| Gameplay Motion | Resolves the current instruction through MotionSmith GAS (Gameplay Animation System) and uses a prepared motion solution when available. |
| Generate | Generates motion from the current instruction using the MotionSmith generation pipeline when a custom or open-ended performance is required. |
| Bake to Rig | Transfers the evaluated character motion into the supported Control Rig workflow so the performance can be refined with Control Rig controls and keyframes. |
| Bake Anim | Creates a standard Unreal Engine animation asset from the current evaluated motion for use outside the active Sequencer workflow. |
| Start Backend | Starts the local MotionSmith generation backend required for Kimodo-based motion generation. |
| Stop Backend | Stops the local MotionSmith generation backend when generation is no longer required. |
Route editing, prepared motion placement, generated motion, continuation and Control Rig refinement are designed to remain part of the same shot-level workflow.
Prompt sections in the timeline
Typical Sequencer workflow
Set the segment duration
Choose the intended timing for the next motion section using Duration.
Choose the motion path
Use Gameplay Motion for prepared gameplay actions or Generate when custom Kimodo-generated motion is required.
Extend the performance
Use Add Segment to continue after the current motion while preserving previously committed sections.
Refine or export
Use Bake to Rig for Control Rig refinement or Bake Anim when a standard Unreal animation asset is required.
Prepare and polish supported characters
MotionSmith can prepare supported characters for the mixed Sequencer Control Rig workflow. This allows generated or adapted motion to remain the broad performance layer while Control Rig is used for shot-specific refinement.
Animation Controls panel
Typical Control Rig refinement
- Pose corrections
- Hand placement
- Upper-body direction
- Look direction
- Shot-specific contact corrections
Primary supported character paths
| Character Family | Status / Notes |
|---|---|
| UE5 Manny / Quinn | Primary supported mannequin path |
| MetaHuman | Supported for MetaHumans created with the current UE 5.8 pipeline |
| AccuRig | Supported in the current V2 animation path |
| Mixamo | Supported — any model rigged with a Mixamo skeleton |
| Character Creator (CC) | Supported — any model rigged with a Character Creator skeleton |
Common problems
Character will not follow the ground
Check the floor mesh collision first. The visible surface and collision surface must agree closely enough for the route analyzer to resolve a valid grounded path.
Route reports an obstacle on an apparently clear floor
Incorrect Simple or Convex collision can create false blocked regions. Replace or simplify the collision
setup,
or use Use Complex Collision As Simple where appropriate.
Control Rig is not available
Confirm that the Sequencer Mixed Control Rig plugin is enabled and that the selected character follows a supported preparation path.
Continuation starts from the wrong place
Make sure the new instruction is being appended after the previously committed segment rather than rebuilding the entire route.
Generated action is used instead of Gameplay Motion
This usually means the instruction did not resolve to an available prepared motion path and MotionSmith routed the segment to Kimodo.
The backend does not start
Open Project Settings → Plugins → MotionSmith Pro and click Run Pre-Flight. Each failed check shows a recommended action. If the runtime is missing, use Download Runtime. After fixing the problem, start the backend again from the Sequencer bar or use Restart Backend in the MotionSmith panel.
Meta Llama is reported as missing
Make sure your Hugging Face access to Meta-Llama-3-8B-Instruct was approved and the download finished.
If you set Llama Model Folder, it must point to the folder that contains
config.json,
the tokenizer files and the .safetensors weights, not to a parent folder.
Generation fails with a GPU out-of-memory error
Close other applications that use the GPU and lower Samples.
Keep Text Encoder Device (Project Settings → MotionSmith Pro → Advanced) set to
cpu;
with the text encoder on the GPU, Kimodo needs about 17 GB of VRAM.
Saved/Logs folder.
Third-Party Notices
MotionSmith Pro is Copyright (c) 2026 MotionSmith AI. All Rights Reserved. It is distributed on Fab under the Fab End User License Agreement. Each third-party component below remains under its own license.
Meta Llama 3 is licensed under the Meta Llama 3 Community License, Copyright (c) Meta Platforms, Inc. All Rights Reserved. It is not distributed with MotionSmith; users download it from Hugging Face.
NVIDIA Kimodo
Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. Licensed under the Apache License, Version 2.0 (full text below). github.com/nv-tlabs/kimodo
Source/ThirdParty/Kimodo: BVH parsing, coordinate conversion and SOMA77 reference data. The license is included asLICENSE.txt.Content/Python/Lib/site-packages/motionsmith_kimodo_multiprompt.py: multi-prompt generation loops adapted fromKimodo._multiprompt(). The MotionSmith worker scripts inContent/Python/MotionSmithBackendare MotionSmith code that calls the Kimodo API.
These portions were modified by MotionSmith AI.
NVIDIA SOMA body model (SOMA-X)
Copyright (c) NVIDIA CORPORATION & AFFILIATES. Apache License, Version 2.0. The SOMA77 skeleton and mesh assets are derived from SOMA-X.
MotionSmith Runtime components (not included in the plugin)
- Kimodo-SOMA-RP-v1.1 model weights: NVIDIA Open Model License
- LLM2Vec (McGill NLP): MIT License, Copyright (c) 2024 McGill NLP
- Python, PyTorch and dependencies: their own licenses, in the Licenses folder of the runtime package
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