# Body

> Track one body's pose into control lanes: torso position, hand positions, arm spread, lean, crouch and presence.

Source: https://docs.tune.toys/nodes/sense.body/

Body tracks one person's pose and turns it into control lanes.

## What it does

Connect a video source to `video`. The `control` output has 11 lanes from 0 to 1, in order: x, y, z, hand.l.x, hand.l.y, hand.r.x, hand.r.y, spread, lean, crouch, present. It runs a MediaPipe model in the browser. The model downloads after the person consents, with its size shown first, and is cached afterwards. Nothing is uploaded. When tracking is lost the lanes hold their last values and `present` falls to 0 after 220 ms.

## When to use it

Use it for whole-body control: arm spread, lean and crouch. See [Sensing](https://docs.tune.toys/concepts/sensing/).

## Ports

<!-- ports:start -->

| Port      | Direction | Signal  | Lanes |
| --------- | --------- | ------- | ----- |
| `video`   | Input     | Video   | 1     |
| `control` | Output    | Control | 11    |

<!-- ports:end -->

## Parameters

<!-- parameters:start -->

| Parameter  | Label   | Range     | Default | Unit | Scale  | Notes                                                                    |
| ---------- | ------- | --------- | ------- | ---- | ------ | ------------------------------------------------------------------------ |
| `model`    | Model   | 0 to 2    | 0       |      | linear | Smaller is faster; larger is steadier. Choices: 0 Lite, 1 Full, 2 Heavy. |
| `mirror`   | Mirror  | 0 to 1    | 1       |      | linear | Flip x for a mirrored picture. Choices: 0 As captured, 1 Mirrored.       |
| `smooth`   | Smooth  | 0 to 1000 | 80      | ms   | linear | One-pole smoothing of every lane.                                        |
| `delegate` | Compute | 0 to 1    | 0       |      | linear | Run the model on the GPU or the CPU. Choices: 0 GPU, 1 CPU.              |

<!-- parameters:end -->

### Model (`model`)

Chooses the pose model; larger values trade speed for accuracy.

### Mirror (`mirror`)

Flips x so movement matches a mirror when on.

### Smooth (`smooth`)

Smoothing time in milliseconds for the lanes.

### Compute (`delegate`)

Chooses where the model runs: 0 for the default, 1 for the alternative.

## Tips

- Use [Select lanes](https://docs.tune.toys/nodes/ctl.select/) with `"audio": {"channels": 1, "firstChannel": N}` to pick one lane; lanes count from 1.
- A one-lane control cable can drive any parameter through its `{ "node": "x", "port": "@param" }` socket.

## See also

[Select lanes](https://docs.tune.toys/nodes/ctl.select/), [Scale](https://docs.tune.toys/nodes/ctl.scale/), [Smooth](https://docs.tune.toys/nodes/ctl.smooth/), [Sensing](https://docs.tune.toys/concepts/sensing/), [Control lanes](https://docs.tune.toys/concepts/control-lanes/).