Documentation · v1.6.2
Motion Flow guide
Everything you need to install the add-on, generate your first motion, and control the result in Blender.
What is Motion Flow?
Motion Flow is a Blender add-on for AI-assisted character animation. It uses NVIDIA’s ARDY model to create full-body motion from short text instructions. You can guide the result with pose constraints and then edit the generated keyframes in Blender.
Everything runs locally. Blender starts and manages a local generation server on your computer. Your prompts and animation data do not need to be sent to a cloud service.
System requirements
This packaged release is built for 64-bit Windows and NVIDIA CUDA graphics.
VRAM: the model project does not state one fixed minimum. A GPU with more VRAM can handle inference more comfortably. ARDY was tested by NVIDIA on the RTX 4090 and A100.
Installation
There are two downloads: the Blender add-on and the model files. Keep both ZIP files compressed until the steps below ask for them.
- 1
Install the add-on
Open Blender. Go to Edit → Preferences → Add-ons, choose Install from Disk, and select
ardy_blender_addon.zip. Enable Motion Flow when it appears. - 2
Set up the local server
Open the Motion Flow add-on preferences. Under Server Environment Setup, click Setup Local Server. The bundled Python runtime and dependencies are installed without downloading extra packages.
This may take a few minutes. Keep Blender open until the status changes to “Server Installed.”
- 3
Install the models
In the same preferences, find Local Models Installation. Choose
ardy_models_bundle.zip, then click Install Models from ZIP. - 4
Check the status
Setup is complete when the preferences show Ready (Server & Models Installed).
Do not manually unpack the add-on before installing it. Do not rename or change files inside the model bundle.
Quick start
Follow this short flow to create a clean first result.
Open the panel
In the 3D Viewport, press N and open the Motion Flow tab.
Keep one prompt
Remove the sample steps until one remains. Enter a clear action and choose its duration.
Generate
Click Generate Motion Sequence. The first run takes longer while the model loads.
Review
Press play in Blender. The generated action is stored as keyframes on a Core27 armature.
A person walks forward, stops, and waves with the right hand.
Prompts and prompt chains
A prompt is a short, physical description of the motion. Each prompt has its own duration. Add several prompts to create a longer sequence.
Use + and − beside the prompt list.
Use the up and down arrows. Motion plays from the top prompt to the bottom.
Set the length of the selected step in seconds.
Motion Flow overlaps nearby steps slightly to make transitions smoother.
Write prompts that describe movement
“A person takes three slow steps forward and looks left.”
“A person crouches, jumps up, and lands on both feet.”
“Make it cool and cinematic.”
Long stories, camera directions, clothing, or details about the room.
Constraints
Constraints tell the model where part of the character should be at a certain time. They guide generation; they are not normal Blender constraint modifiers.
Bone constraint
Select a supported bone in Pose Mode, move to the target timeline frame, and click Bone. Motion Flow captures its position and rotation.
Body section constraint
Choose Full Body, Left Hand, Right Hand, Left Foot, or Right Foot. Pose the exact ARDY Core27 rig, then click Section to capture that part of the pose.
Preserved range
Set a start and end frame, choose a body section, and click Preserve Existing Range. Motion Flow samples the current animation in that range and uses it during generation.
Include or ignore the selected constraint without deleting it.
0 ignores the target. 1 follows it as strongly as possible.
Capture the current selected bone or section pose again.
The exact Blender timeline frame where the target applies.
Use a few meaningful constraints. Too many targets—or targets that fight each other—can create stiff or unstable motion.
Generation settings
Text strength
Controls how strongly the model follows your words. Raise it when the main action is being missed; lower it if movement looks forced.
Constraint strength
Controls the overall weight of pose targets. This works together with the influence value on each constraint.
Motion cleanup
Runs post-processing to improve contacts and reduce common artifacts. Leave it on for most human motion.
Fixed seed
Makes repeated runs more consistent. Keep the same prompt, settings, and seed to compare constraint changes.
Server controls
The add-on starts a local API server when you generate motion. The default address is http://127.0.0.1:8000.
Loads the local service manually before generation.
Closes only the server started by this Blender session.
Stops the managed server after a period without use. The default is 10 minutes; use 0 to keep it running.
Advanced users can replace the local address with another compatible Motion Flow API URL.
The first generation after starting the server takes longer because the AI model must load into GPU memory.
Rig output
Choose how generated animation is placed in your scene from the add-on preferences.
Overwrite Existing
Reuse a compatible Core27 armature and replace its current generated animation. This keeps the scene tidy.
Import New Rig
Create a fresh Core27 character for every generation. Use this when comparing several results side by side.
Prompt tips
- Use physical verbs: walk, reach, turn, crouch, wave, kick.
- State direction clearly: forward, left, clockwise, toward the floor.
- Keep each prompt focused on one short action or action group.
- Break a long performance into several prompt steps.
- Use neutral physical descriptions instead of demographic labels.
- Try a fixed seed before changing one setting at a time.
Troubleshooting
The status says “Models Missing.”+
Open add-on preferences. Select the original ardy_models_bundle.zip and run Install Models from ZIP. Wait for the Ready message before generating.
The local server does not start.+
Check that server setup finished, the default port 8000 is free, and security software has not blocked the bundled python.exe. Open Diagnostics & Logs → Open Logs File for the exact error.
Generation is very slow the first time.+
This is expected while the model loads into GPU memory. Later generations are faster until the idle timeout stops the server.
A pose constraint is ignored.+
Check that it is enabled, its influence is above 0, and its frame falls inside the generated sequence. Raise constraint strength gradually. Confirm that the selected bone maps to the Core27 rig.
The character slides or misses the prompt.+
Shorten and simplify the prompt. Leave motion cleanup on, reduce conflicting constraints, or generate another result with a different seed. Some artifacts are a known model limitation.
Blender becomes low on memory.+
Stop the managed server when it is not needed, close other GPU-heavy apps, and work with shorter motion steps. Restart Blender to fully release resources.
Known limitations
Generated animation may need cleanup. ARDY can sometimes create foot skating, miss part of a prompt, or struggle with actions outside its training data. It works best with locomotion, gestures, combat, dance, and everyday movement.
The model does not understand objects in your Blender scene. It aims for realistic human movement, not cartoon motion or physically impossible actions. The current add-on release generates a single Core27 character skeleton.
Licenses
Declared in the Blender extension manifest.
Applies to the ARDY code included with the project.
Allows commercial and non-commercial use subject to NVIDIA’s agreement.
Open the agreement ↗Make something move.
Return to Blender, open the Motion Flow panel, and start with one clear action.
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