git:20260930.696f27a to git:20261010.4ade947

---

name: generate-motion

description: "Attach an animation clip to a rigged character from the curated Meshy motion library — idle, walk, run, attack — wired via AnimationPlayer."

license: MIT

compatibility: [Cursor, Claude Code, Windsurf, Codex]

category: animation

user-invocable: false

allowed-tools: Read Grep summer_search_assets summer_list_my_assets summer_get_asset summer_get_asset_download_url summer_generate_motion summer_inspect_resource summer_get_scene_tree summer_add_node summer_set_prop summer_set_resource_property summer_save_scene

paths: ["**/*.tscn", "**/*.tres", "**/*.gd"]

---

# Generate Motion — Curated Meshy Library

The target must be a **Meshy-rigged humanoid** — a `rigAssetId` from a prior `summer_generate_3d({ kind: "image-to-3d", imageUrl: "...", options: { rig: true } })` call. The result job includes `rigAssetId`. If the user points at a non-rigged mesh, stop and route to `asset-strategy` (or directly call `summer_generate_3d` with `options.rig: true`) before generating motion.

> **Custom or non-humanoid motion** (e.g. "drops to one knee, draws bow", a

> nodding flower, a creature) goes to the `text-to-motion` skill

> (`backend: "text-to-motion"`) when the server has it enabled; otherwise fall

> back to hand-authoring in Summer Engine or importing from Mixamo.

## When to use this skill

- "Add a walk animation to the goblin."

- "I need an idle, a run, and an attack on this character."

- "Death animation for the enemy when HP hits zero."

- The user has a rigged character and zero animations on it.

## When NOT to use this skill

- The user wants to apply an *existing* animation to a *new* model — use `retarget` instead. Don't regenerate.

- The user wants state-machine wiring (idle → walk → run blend) — generate the clips here, then hand off to `animation-tree`.

- The user wants facial / lipsync animation — that's `facial-and-lipsync`.

- The mesh isn't rigged. Rig first; never call `summer_generate_motion` on a static `.glb`.

- The user wants procedural look-at, IK, foot placement — that's `procedural-animation`.

- The user described a **custom signature move** that isn't on the curated list — use `text-to-motion`; if the server answers `backend_unavailable`, use the manual-authoring fallback below.

## Steps

### 1. Verify the target is a rigged humanoid

```

summer_search_assets(query="<character name>", assetType="3d_model", source="my_assets")

```

The result must include `rigAssetId: <id>` on a Meshy rig. If it shows `rigAssetId: null`, the model isn't rigged — stop, propose `summer_generate_3d({ kind: "image-to-3d", imageUrl: "...", options: { rig: true } })` first (the result includes `rigAssetId`), or route to `asset-strategy`.

### 2. Confirm with the user before spending

### 3. Call the tool

```

summer_generate_motion(

rigAssetId: "<id>",

backend: "meshy-library", // curated library (default)

motionName: "run" // exact name from the curated list — see Reference card

)

```

With the default `wait: true` the tool polls to completion and returns the job

result with `animationAssetId` in it. Don't assume any other field is present —

resolve the asset to get stable file/download metadata:

```

summer_get_asset(assetId="<animationAssetId>")

```

### 4. Attach to the character's AnimationPlayer

```

summer_inspect_node(path="./World/Goblin") // confirm it has an AnimationPlayer child

summer_add_node(scenePath="res://main.tscn", parent="./World/Goblin", type="AnimationPlayer", name="AnimationPlayer") // only if missing

summer_set_resource_property(

scenePath="res://main.tscn",

nodePath="./World/Goblin/AnimationPlayer",

resourceProperty="libraries/default",

subProperty="<motion_name>",

value="<animationAssetId>"

)

summer_save_scene(scenePath="res://main.tscn")

```

`scenePath` is required on `summer_add_node`, `summer_set_resource_property` and

`summer_save_scene`. `summer_inspect_node` takes only `path` — it has no

`scenePath` and reads the currently-edited scene.

If the character will use multiple clips, leave the AnimationPlayer in place — every subsequent generation appends to the same library. State-machine wiring belongs to `animation-tree`, not here.

## Confirmation gates

- **Before attaching:** state which AnimationPlayer and which library slot. Wait for OK.

- **After generation:** if the user hasn't seen the preview, link `previewUrl` and ask "land or regenerate?" before wiring it into the scene.

## Reference card

### Curated motion library — what `motionName` actually accepts

There are **five** short canonical aliases, and only five:

`idle`, `walk`, `run`, `jump`, `attack`

Everything else must be an **exact raw Meshy library name** (or its display name,

or its numeric action id 0–696). The library is 678 entries, and its naming is

nothing like a tidy snake_case scheme — real names look like `Walking_Woman`,

`Jump_Run`, `Run_02`, `Hit_Reaction`, `Roll_Dodge`, `Block1`, `Dead`,

`Stand_Dodge`, `Triple_Combo_Attack`, `Wave_One_Hand`, `Chair_Sit_Idle_F`,

`Lean_Forward_Sprint`.

Plausible-looking names that do **not** resolve, verified against the resolver:

`attack_sword`, `hit_react`, `death`, `sprint`, `block`, `dodge_left`,

`crouch_idle`, `walk_back`, `run_strafe_left`, `jump_land`, `idle_combat`,

So: if the user asks for something outside the five aliases, do not guess a

snake_case name. Either use one of the five, quote an exact raw library name you

have actually seen, or route to the manual-authoring fallback.

### Pitfalls

- **Invented `motionName` strings fail.** `"run_fast"`, `"attack_sword"`, `"death"` all resolve to nothing and the call errors. Name resolution is exact — five aliases, or a real library name / display name / numeric id. Do not extrapolate a naming scheme.

- **Locomotion clips have a forward bias.** Meshy's `run` translates the root forward by ~5m. Either the code drives movement (then the baked root translation causes a lunge-and-snap every loop — strip it) or the clip does via `root_motion_track` + `get_root_motion_position()` — never both. The full root-motion setup and its playtest verification live in `character-animation-wiring`.

- **Rig pose mismatch.** If your rig was rigged with a non-T-pose reference image, the limbs may bend wrong. Re-rig from a T-pose mannequin (see `asset-strategy`) before re-generating.

- **Rig still preparing.** New rigs need ~3 minutes after the rig job completes before the animation library is ready. The MCP route returns 425 "animations_preparing" if you call too early. Wait and retry.

## Anti-patterns

- Calling `summer_generate_motion` on a `.glb` that wasn't rigged — wastes a generation; the API errors but only after 30s.

- Generating the same clip twice because you forgot to save the `animationAssetId` from the first call. Search the asset library first: `summer_search_assets(query: "goblin run", assetType: "animation", source: "my_assets")`.

- Wiring clips into an AnimationTree inside this skill. That's the next skill's job. Generate, attach, hand off.

- Asking the model to invent a `motionName` that isn't on the list. Quote from the list verbatim, or fall back to manual authoring.

## Edge cases

- **Custom signature move** (e.g. "drops to one knee, draws bow"). The custom

prompt-driven route is `text-to-motion`. If it is unavailable, workarounds:

hand-author the clip in Summer Engine's animation panel, import a licensed

clip as an `AnimationLibrary`, or compose curated clips in an

`AnimationTree` OneShot blend.

- **Quadruped rig.** Meshy library is humanoid-only. For quadrupeds and other non-humanoid rigs use `text-to-motion`, or hand-author / import an external library.

- **Character is < 1m tall (child / dwarf).** Library clips assume a ~1.8m humanoid. Apply the clip; the proportions retarget but stride length looks long. Either accept it or tune `playback_speed` on the AnimationPlayer track.

- **Character has wings / tail.** The library ignores the extra bones — they sag. Hand-author additive overlays for the extra bones, or accept the visual hit.

## Fallback (no MCP)

The user can upload to Meshy directly at meshy.ai, generate through the

dashboard, download `.glb`, and import it as an `AnimationLibrary` in Summer

Engine.

## Handoff

- After generating locomotion clips, suggest `character-animation-wiring` — the end-to-end wiring path (inspect what landed, idle/walk/run state machine with blend times, footstep method tracks, root motion, playtest proof). For blend spaces and attack/hit overlays on top, `animation-tree`.

- After generating a one-shot (death, hit-react), suggest `design-npc` to fire it from the behavior state machine.

- For first-person hand animations on a player, use this skill on a *hands-only rig* and then `fps-controller` for the wiring.

- If the user wants to apply these clips to a second character, hand off to `retarget`.

## See also

- `asset-strategy` — how to get a Meshy-rigged character in the first place.

- `animation-tree` — wire the generated clips into a state machine.

- `retarget` — re-use one library across many characters without regenerating.