# Polyline 3D

A **Polyline 3D** is a flexible annotation tool that allows users to draw a continuous line in 3D space with a starting point, an endpoint, and an unlimited number of joints or nodes in between. Each node marks a point in space where the line changes direction, enabling annotators to outline complex shapes or paths.

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## Use Case

This tool is ideal for tracing irregular or elongated objects such as roads, pipelines, or boundaries, where precise line-based annotation is needed. The polyline's flexibility ensures that even intricate curves and angles can be accurately represented in the 3D point cloud.

{% hint style="info" %}
Polylines 3D can be created in point cloud.
{% endhint %}

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## Create Polyline

1. Click on the '+' icon of the class from the [class list](https://docs.imerit-prod.io/tool-layout#id-3.-class-list)
2. Select 'Polyline' from the drawing tool list.

   <figure><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXeGsKhyOg5Dc95PFWH7uYAYTPOdwo1o4SiSKE_awUqqdRpYBYlQ2q14Am_iJPXnY0fvCfL9xjYGb5PmhXQ4B7HQW3Vp-zVbSNQ00vyxVBWVknKa5H4fj0YKIOjeKnF09m-ErxlBslfPlmKH42eqE2sa8Cw?key=lGhAQLv5xC3Ciuwf6zBTGQ" alt=""><figcaption></figcaption></figure>
3. The cursor pointer shows a grey circle marker to it while hovering over the points.
4. Click to draw a polyline 3D on the desired object of interest. Move the mouse to the next desired location, and a line extending from the initial point will dynamically follow the cursor.&#x20;
   * The yellow arrow heads appearing are signifying the [direction of the polyline](https://docs.imerit-prod.io/annotation-tool/key-features/polyline-direction).
5. The projection of the polyline is simultaneously reflected in the corresponding images of the [image panel](https://docs.imerit-prod.io/tool-layout#id-5.-image-panel).
6. `Right-Click` to indicate the end of the polyline.
   * `Right-Click` will introduce another point
7. A status box appears, confirming the width (thickness) of the polyline. By default, it is set to 0 meters.
8. Enter the [annotation details](https://docs.imerit-prod.io/steps-to-label#id-6.-annotation-detail-input).
9. The saved instance will appear on the [class list](https://docs.imerit-prod.io/tool-layout#id-3.-class-list) with a zig-zag line icon next to the Instance name.

   <figure><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXfj-MXObYyQcKZJ-w75BiZpHwpdAJZ3LmyYVXsoeROwz1mCrQbey6eGxlKuAUlEOWejvLtGyI21ajzmcjqFhJRz9S_pHczSCiOYKA9FAaThTl_oOoxsGKYkcW4z2z2Sn-95Vem5Ytqwa83jjz8JjLgegTW3?key=lGhAQLv5xC3Ciuwf6zBTGQ" alt=""><figcaption></figcaption></figure>

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## Modify Polyline 3D

The polyline 3D can be re-selected and modified by:

* Select a vertex that needs to be edited and drag it to modify its location.
* Add a vertex by hovering over the edge of the polygon and left-click when the ‘+’ symbol appears.
* Delete the vertex by dragging it into its immediate adjacent one OR press `CTRL + Right-click`

Learn how to use splitting, merging and extending polylines [here](https://docs.imerit-prod.io/annotation-tool/key-features/split-merge-and-extend-3d-polylines).

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## Duplicate Polyline 3D

Polyline 3D can be duplicated by selecting the annotation and pressing `Ctrl D.` This will duplicate the cuboid and allow the user to drop it at the desired location in the point cloud on `mouse-click`.

### Translate Polyline 3D&#x20;

&#x20;Reposition the entire 3D Polyline on any one axis or 3D plane

1. Labeller to select the polyline

#### Translate on Z-axis

2. Hold down the key Shift, a blue bar appears&#x20;
3. Click and drag the blue bar

#### Translate on Y-axis&#x20;

2. Hold the ALT, a green bar appears&#x20;
3. Click and drag the green bar

#### Translate on X- axis&#x20;

2. Hold down the CTRL, a red bar appears&#x20;
3. Click and drag the red bar

#### Translate in Any Direction

1. Select the 3D polyline
2. Press CTRL+M
3. The polyline snaps to the mouse, and on moving the mouse, the polyline too will move.

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## Copy Paste Polyline

Polyline can be copy and pasted to another frame where it does not exist (`Ctrl+C` / `Ctrl+V`). The [annotation detail input ](https://docs.imerit-prod.io/steps-to-label#id-6.-annotation-detail-input)prompts user for input on pasting annotation. By default, the pasted Polyline will share the same Instance ID as the one of the copied Polyline 3D.

{% hint style="success" %}
Copy and pasting of Polyline 3D works inter-frame (across frames where the same instance ID doesn't exist).
{% endhint %}