> For the complete documentation index, see [llms.txt](https://alpaca4d.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://alpaca4d.gitbook.io/docs/basics/results/nodal-displacements.md).

# Nodal Displacements

Displacement, rotation, velocity and acceleration at every node of the model.

## 🔧 Grasshopper component

`Nodal Displacements (Alpaca4d)` — **Alpaca4d ▸ 08\_NumericalOutput**

### Inputs

| Name        | Nick          | Type    | Default | Description                                                                                                                           |
| ----------- | ------------- | ------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| AlpacaModel | `AlpacaModel` | Model   | —       | The analysed model.                                                                                                                   |
| History     | `History`     | Boolean | `false` | Read every recorded step instead of one. Each output becomes a tree `{step}` holding that step's value per node. **Step** is ignored. |
| Step        | `Step`        | Integer | `0`     | Analysis step, or mode number for a modal model.                                                                                      |

### Outputs

| Name         | Nick           | Type          | Description                                       |
| ------------ | -------------- | ------------- | ------------------------------------------------- |
| Displacement | `Displacement` | Vector (list) | Translation at each node, in `m`, global axes.    |
| Rotation     | `Rotation`     | Vector (list) | Rotation at each node, in `rad`, global axes.     |
| --------     | `--------`     | —             | A visual separator. Nothing comes out of it.      |
| Velocity     | `Velocity`     | Vector (list) | Velocity, in `m/s`. Transient analysis only.      |
| Acceleration | `Acceleration` | Vector (list) | Acceleration, in `m/s²`. Transient analysis only. |

The lists are ordered by node tag, which is the order [Assemble](/docs/basics/assemble.md) numbered the nodes in — not the order you drew anything.

## 📈 When to use it

**Use it when**

* You need a deflection to check against a limit.
* You want the displaced shape as data rather than as a picture.
* You are extracting a response history at a control node: sweep **Step** and collect one component.

**Do not use it when**

* You only want to *look* at the deformed shape → [View Results](/docs/basics/visualisation/view-results.md) draws it directly.

{% hint style="info" %}
On a model from [Natural Vibration](/docs/basics/analysis/natural-vibration.md), **Displacement** is the **mode shape**, and `Step` selects the mode. Mode shapes are normalised, so the magnitudes are not physical displacements — only their relative values mean anything.
{% endhint %}