v1.0.1 · Unity 6000.0+

PromptMotion Lite

Free AI text-to-animation for Unity. Generate humanoid Mecanim clips from plain-English prompts right in the Editor — 5 free lifetime generations, no purchase or account required. PromptMotion Lite - AI Animation Generator.

Unity 6000.0+ Humanoid Mecanim URP / HDRP / Built-in Editor Tool
Free to try. Activate with your email to unlock 5 lifetime AI generations — no purchase, no account. When you need more, upgrade to PromptMotion (Standard, 50/month) or PromptMotion Pro (150/month + Pro toolset) on the Unity Asset Store.
Generation requires an internet connection and a free email activation. Generated clips are saved to your project and work offline thereafter.

Getting-started topics are under Installation and Quick Start; the generation workflow under Generator; shared concepts under Concepts and Reference.

Compare Editions

You're using Lite (free). Standard and Pro add a monthly allowance, the bundled Animation Library, and — in Pro — the animation toolset.

  Lite
Free (this asset)
PromptMotion
Standard
PromptMotion Pro
Pro
PriceFreePaidPaid
AI generations5 lifetime50 / month150 / month
ActivationEmail codeAsset Store invoiceAsset Store invoice
Text-to-animation Generator
Any Humanoid rig + auto-retarget
Live preview, history, apply-to-character
Cached prompts are free (don't count)
Bundled Animation Library (starter clips)
Pro toolset — batch & variation generation
Pro toolset — Mecanim wiring (controllers + blend trees)
Pro toolset — clip cleanup (trim / loop / mirror / smooth)
Pro toolset — clip sequencer + prompt presets

Installation

Import once. The Generator window lights up immediately.

From the Unity Asset Store

Open Package Manager
In Unity 6000.0 or later, open Window → Package Manager and switch the dropdown to My Assets.
Find PromptMotion, click Download then Import
Accept the import dialog with everything checked. The package lands at Assets/PromptMotion/.
Wait for compile
Unity recompiles editor scripts. The first time takes ~30 s; subsequent imports are faster.
Open the window
Window → PromptMotion → Generator.

Prerequisites

PromptMotion uses two Unity packages that ship with a default Unity 6 install:

If your project doesn't already have Newtonsoft.Json, Unity prompts to add it on first import. Click Yes.

What gets installed

Assets/PromptMotion/
  Generator/                  // AI generator window + auth + HTTP
    Editor/
  Shared/                     // ClipApplier, Avatar validators, Preview viewport
  Generated/                  // Output folder created on first generation
    Controllers/              // Per-character AnimatorControllers
  Documentation/              // You are hereProject
No character is bundled. You bring your own Humanoid rig — anything from Mixamo, Synty, Quaternius, or a custom skeleton works as long as the Avatar is configured as Humanoid. Generated clips retarget to whatever you provide.

Quick Start: Generator

Zero to your first generated clip in about a minute (plus generation time).

Open the Generator window
Menu: Window → PromptMotion → Generator.
Activate with your email
Enter your email in the banner and click Send code. We email you a 6-digit code (valid 15 minutes); type it in and click Activate. This unlocks 5 free lifetime generations — no purchase or account required.
Assign a character
Select a Humanoid character in your scene Hierarchy, or drag a prefab into the character slot. The window validates the rig and shows a green checkmark when ready.
Type a prompt
Describe the motion: "walking forward confidently", "sitting down on a chair, then standing back up", "waving hello with the right hand". Set duration (1–10 s; default 4 s).
Click ⚡ Generate
Wait ~38 s (warm) or ~83 s (cold start). The button counts elapsed seconds. When done, the FBX is saved under Assets/PromptMotion/Generated/ and the clip is auto-applied to your character.
Hit Play
Press Play in the Unity editor to see the clip on your character. See How It Works for what happens behind the scenes.
💡
Cache hits are free. Identical (prompt, duration, seed) returns the previously-generated FBX in milliseconds and uses none of your free generations. The status banner reads ✓ Cached result — no allowance used.

How It Works

A single round-trip from the Editor to the PromptMotion backend.

Prompt Backend Kimodo Retarget FBX Auto-Import Apply
  1. You type a prompt and click ⚡ Generate.
  2. The window posts { prompt, duration_seconds, seed } to https://api.promptmotion.dev/prod/generate with your activation email as authentication.
  3. The backend runs the prompt through NVIDIA's Kimodo (SOMA-RP) text-to-motion model.
  4. The raw motion is retargeted to a standard Humanoid skeleton on the server.
  5. The server returns a Mecanim-ready .fbx file.
  6. The client saves the FBX under Assets/PromptMotion/Generated/. An AssetPostprocessor auto-configures it as Animation Type: Humanoid.
  7. The window applies the resulting AnimationClip to your selected character via ClipApplier.

You don't need to know anything about Kimodo, retargeting, or import settings — the pipeline is fully automated. The output is a standard Unity AnimationClip; you can edit, blend, retarget, mask, or layer it like any other clip.

Generation is editor-only. Once an FBX is on disk, the asset is just an AnimationClip and works in any build target Unity supports (standalone, mobile, console, WebGL). You can't generate new animations from a runtime build.

🔒 Activation

A free email activation unlocks the trial. No purchase, no signup, no API key.

How activation works

  1. Enter your email in the Generator banner and click Send code.
  2. We email you a 6-digit code (valid 15 minutes).
  3. Type the code in and click Activate. That unlocks 5 free lifetime generations.

Your email is used only to grant one free trial and prevent abuse — it is never used for marketing or shared with third parties.

Reinstalling, or moving to another machine

Your 5 free generations are tied to your email. Just enter the same email again on the new install — we recognise the existing trial and restore it instantly, no new code required. (Window → PromptMotion → Reset Activation clears the locally-stored email if you ever need to re-enter it.)

One free trial per machine

The free trial is one-per-install: entering a different email on a machine that already activated one won't grant another 5 generations. For more, upgrade to PromptMotion (50/month) or PromptMotion Pro (150/month).

What gets sent to the server

Only this:

Not sent: real name, IP (other than what's inherent to HTTPS), Unity Editor analytics, scene contents, or any telemetry beyond the above.

Free Trial

5 lifetime generations included. Cached prompts use none of your trial.

How the trial works

Every successful generation uses one of your 5 free lifetime generations. Cached results — identical (prompt, duration, seed) — do not count. The trial is a one-time lifetime allowance, not a monthly reset.

The Ready banner shows your remaining count, for example: 3 of 5 free generations remaining.

What happens when the trial is used up

Writing Prompts

Describe the motion. The model never sees your character.

Prompts that work well

Prompts that work less well

Current model limitations

✋ No fingers

Hand pose is a fixed default. The model doesn't pose individual fingers.

😐 No facial animation

Output is body skeleton only. Faces stay neutral.

👤 Single character

No interactions with other rigs, props, or scene geometry.

⏲ Approximate length

If your prompt's natural length is shorter than the duration, the model may pad with idling. Pick a duration that matches.

Duration & seed

Duration: integer between 1 and 10 seconds. Longer clips take slightly longer to generate but use the same single generation from your trial.

Seed: leave blank to let the server randomize. Set a specific integer to make the output reproducible — same prompt + same duration + same seed = same FBX (and a cache hit).

💡
Commit to specific wording. Cache keys are exact-match on (prompt, duration, seed). Whitespace and capitalisation differences produce distinct cache entries. Typo'ing the same phrase twice uses two of your free generations.

🧍 Character Requirements

Both tools require a Humanoid rig. Generic skeletons aren't supported in v1.0.

What "Humanoid" means here

Validator badges

Drop a character into the slot and the window checks:

BadgeStateWhat to do
✓ ValidAnimator + valid Humanoid Avatar present.Ready to generate / apply.
⚠ No AvatarRig has bones but the Avatar slot is empty.Click Auto-Configure to build one from bone names.
✗ No AnimatorThe GameObject has no Animator.Add an Animator component, assign a Humanoid Avatar.
✗ GenericAvatar is configured but as Generic, not Humanoid.Re-import the model with Animation Type = Humanoid.
✗ Invalid bone mappingAvatar exists but Unity considers it broken.Re-import the model.

T-pose preferred

Characters configured from a clean T-pose retarget cleanest. A-pose works but may produce slight shoulder offset on extreme clips. Bind-pose-flopped rigs (one arm forward) often produce wrong shoulder rotation — re-import in T-pose if you see shoulders pop.

📁 Generated Files

Where things land, how they're named, what else gets created.

Output location

Every generated FBX lands in:

Assets/PromptMotion/Generated/Path

Naming convention

Each filename embeds the backend's job id, e.g. job_a8f3c1e9.fbx. The job id is unique per generation; cache hits return the same file rather than producing a duplicate.

What gets created besides the FBX

Regenerating with the same prompt

If the cache key matches, no new file is created — the existing FBX is returned. If the seed changes (or you click Random), a fresh FBX is written under a new job id; both files coexist.

The Generated/ folder is yours. Move clips into a tracked subfolder if you want them in version control. The folder is .gitignored by default to keep churn out of repos used by teams.

🔧 Settings

A single ScriptableObject configures the Generator. No secrets, safe to commit.

Settings live as a ScriptableObject at Assets/PromptMotion/Generator/Editor/Settings/Settings.asset. Select it in the Project window to edit in the Inspector.

FieldDefaultDescription
Base Urlhttps://api.promptmotion.devThe backend endpoint. Override only if you're running a self-hosted backend.
Output FolderAssets/PromptMotion/GeneratedWhere downloaded FBXes land. Must be inside Assets/.
Default Duration Seconds4Pre-fill for the duration slider on a fresh prompt.
Verify Timeout Seconds10How long to wait for invoice probe / bind responses.
Status Timeout Seconds10How long to wait for status / refresh calls.
Generate Timeout Seconds180Cap for the generation request. Cold starts can hit ~83 s; 180 s leaves headroom.
Verbose LoggingfalseLogs every step (window open, generation start/complete, account refresh, import config) to the Console with [PromptMotion] prefix. Warnings and errors always log regardless.

Your activation email is stored separately in EditorPrefs and is never written to an asset.

🧍 Humanoid Avatar System

Why the asset is Humanoid-only, and how to fix Generic-rig issues.

PromptMotion relies on Unity's Humanoid Avatar system to retarget a generic skeleton onto whatever character you provide. A few things worth knowing:

Why Humanoid and not Generic

Humanoid is a normalized rig: Unity maps any compatible skeleton to its standard 15 bones (hips, spine, chest, neck, head, shoulders, upper/lower arms, hands, upper/lower legs, feet). A clip authored on a normalized rig retargets to any Humanoid character without manual bone mapping. Generic clips are tied to the source skeleton and don't transfer cleanly.

What Unity needs from your rig

Generic-rig fix

If your character imports as Generic by default and PromptMotion rejects it, re-import:

Select the model FBX in the Project window.
Open the Inspector, click the Rig tab.
Change Animation Type to Humanoid.
Leave Avatar Definition as Create From This Model.
Click Apply. Unity will rebuild the Avatar and report any unmapped bones in the configuration dialog.

Auto-Import Pipeline

An AssetPostprocessor configures every Generated FBX so you don't have to.

What MotionFbxPostprocessor does

For every FBX under Assets/PromptMotion/Generated/:

Files outside Generated/ are not touched — your own model imports are left alone.

Opting out

If you want a Generated FBX to use different import settings, move it out of the Generated folder. The postprocessor only fires on first import and on re-import — once a file is moved elsewhere, the standard Unity Import Settings panel takes over.

Apply to Character

From "I have an AnimationClip" to "the clip is wired into a controller."

ClipApplier handles everything from clip-in-hand to clip-on-character. The Generator uses it automatically after each generation to wire the new clip into your character's Animator.

Three cases handled identically

What gets created

An Animator component is added to the character if one isn't present.
If the Animator's Avatar slot is empty, a Humanoid Avatar is auto-detected from a SkinnedMeshRenderer descendant.
A per-character AnimatorController is loaded or created at Assets/PromptMotion/Generated/Controllers/{character}_Controller.controller.
The new clip is added as a state in the Base Layer. The first state added becomes the default state.

Idempotent

Re-applying the same clip updates the existing state rather than duplicating it. Apply a different clip and a new state is added without disturbing the others.

When auto-apply fails

If the selection isn't a Humanoid character or doesn't have a SkinnedMeshRenderer the validator can find an Avatar from, the window shows a HelpBox with the saved FBX path and instructions to drag the clip in manually. The FBX is on disk either way — auto-apply is just a convenience.

💡 Troubleshooting

Every error code, what it means, and how to recover.

The Generator window shows a status banner with a code-mapped message and a recovery button whenever something goes wrong. Twelve codes total — ten reported by the server, two emitted client-side.

Server-reported codes

TRIAL_CODE_INVALIDAction required

The 6-digit code you entered doesn't match (or too many wrong attempts locked it).

What to do: Re-check the digits from your email. If it keeps failing, click Resend code for a fresh one.

TRIAL_CODE_EXPIREDAction required

Codes are valid for 15 minutes; this one has expired.

What to do: Click Resend code to get a new one.

TRIAL_ALREADY_USEDAction required

This email (or this install) has already used its free trial.

What to do: Use a different email, or upgrade to PromptMotion / PromptMotion Pro for a monthly allowance.

QUOTA_EXHAUSTEDAction required

You've used all 5 of your free lifetime generations.

What to do: Upgrade to PromptMotion (50/month) or PromptMotion Pro (150/month) to keep generating. Your already-generated clips remain in your project.

RATE_LIMITEDAuto-retry

Too many requests in a short window.

What to do: The window auto-retries once after the cooldown shown in the status. If the second attempt also fails, wait a minute and click Try again.

UPSTREAM_ERRORRecoverable

The generation model failed.

What to do: No quota was used. Click Try again. If it persists, vary the prompt slightly — some inputs reproducibly upset the model.

SERVICE_UNAVAILABLEAuto-retry

The backend is busy or warming up.

What to do: The window auto-retries after the cooldown. If the second attempt also fails, try again in a few minutes.

SERVER_ERRORAction required

An unexpected backend error.

What to do: Try again in a few minutes. If it persists, email ragendom@gmail.com with the timestamp from the Console.

BAD_REQUESTRecoverable

Something is malformed in the request.

What to do: Most often an empty prompt — type something descriptive and try again.

Client-side codes

NetworkErrorRecoverable

The client couldn't reach the server.

What to do: Check your internet connection, firewall, or VPN. See the network checklist below if you're behind a corporate firewall.

TimeoutRecoverable

The request took longer than GenerateTimeoutSeconds (default 180 s).

What to do: The server may be overloaded. Try again, or increase the timeout in Settings.asset.

Common issues

Character validation fails

The character isn't a valid Humanoid. See Character Requirements. Most often: Animation Type is set to Generic instead of Humanoid in the model's Rig tab. Re-import as Humanoid.

Preview is black

Almost always a render-pipeline interaction with the preview viewport. Enable Verbose Logging in Settings.asset to see what's happening. The clip generated correctly — only the in-editor preview is affected. Drag the FBX onto your character in the scene Hierarchy to see it animate normally.

Generation hangs

Click Cancel in the window and try again. If the second attempt also hangs, persistent failure usually means the BaseUrl in Settings is misconfigured — check it points to https://api.promptmotion.dev.

Network checklist

If you're behind a corporate firewall, whitelist:

The asset uses Unity's standard UnityWebRequest, which respects your system proxy. No custom protocols, no WebSocket, no peer-to-peer.

FAQ

Quick answers to the questions that come up most.

Can I use PromptMotion without internet?

To generate, no. Generation is a server round-trip and requires HTTPS access to the backend (and a free email activation).

Clips you've already generated are plain Unity AnimationClip assets in your project — those work offline, in Play mode, and in builds.

Are generated animations royalty-free for commercial use?

Yes. You own the generated outputs and can ship them in commercial projects without attribution. The underlying generation model disclaims ownership of generated content; commercial use is permitted.

What happens when I use up my free trial?

New generations pause once all 5 free generations are used. Existing FBXes and cached prompts continue to work. To keep generating, upgrade to PromptMotion (50/month) or PromptMotion Pro (150/month) — see Compare Editions.

What if the service is down?

Generation is paused until it's back — transient errors auto-retry, and failed generations never consume a free generation. Clips you've already generated are unaffected. If an outage looks prolonged, email ragendom@gmail.com.

How do I cancel a generation in progress?

Click the Cancel button that appears in the window during generation. The request is aborted client-side; no quota is consumed for cancelled requests.

Can I use a different character?

Yes — any Humanoid character works. Mixamo, Synty, Quaternius, custom rigs — if Unity recognises it as Humanoid, PromptMotion can target it.

Does this work in builds / at runtime?

Generation is editor-only. Once an FBX is generated, the asset is just an AnimationClip and works in any build target Unity supports — standalone, mobile, console, WebGL.

Can I use this with HDRP?

Yes. The package is render-pipeline-agnostic. It produces standard Mecanim clips that work with URP, HDRP, and Built-in.

My team has multiple developers. Do we each need a license?

Yes. Per Unity Asset Store policy, each seat that uses the asset needs its own license.

Why does the same prompt return "Cached"?

Identical (prompt, duration, seed) produces a cache hit. Cache hits are free and use none of your free generations. If you want a fresh result, change the seed (or click Random).

📬 Support

Need help? We're here for you.

📧

Get in Touch

Bug reports, feature requests, licensing questions — reach out and we'll get back to you.

✉ ragendom@gmail.com

We typically respond within 24–48 hours.

💬 Before contacting
  • Check the Troubleshooting section
  • Refresh your trial status via Refresh in the banner
  • Try the request twice — auto-retry resolves most transient errors
  • Enable Verbose Logging in Settings to capture context
📋 Helpful info to include
  • Unity version (e.g. 6000.0.30f1)
  • PromptMotion version (v1.0.1)
  • Render pipeline (Built-in / URP / HDRP)
  • Steps to reproduce + Console output
PromptMotion Lite is free — there's nothing to refund. When you're ready for more, PromptMotion (50 generations/month) and PromptMotion Pro (150/month plus a Pro animation toolset) are available on the Unity Asset Store.
Enjoying PromptMotion Lite? A review on the Unity Asset Store helps other developers discover it and helps us keep improving it — thank you!

PromptMotion v1.0.1 · Built for Unity 6000.0+

Powered by NVIDIA Kimodo (SOMA-RP-v1) · Support: ragendom@gmail.com