> For the complete documentation index, see [llms.txt](https://docs.imerit.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imerit.net/3d-multi-sensor-fusion/labeling/3d-multi-sensor-fusion-labeling-editor/key-features/polyline-direction.md).

# Polyline Direction

To make lane annotation more intuitive and accurate, directional arrows now appear during polyline creation.

{% hint style="success" %} <img src="/files/mXHEiGg35kYjwl0I4r5p" alt="" data-size="line"> Helps ensure correct lane flow and orientation, especially for traffic-related annotations.
{% endhint %}

![](/files/e5fb34a55178b126c50e2b05bda7e28859b113a1)

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## Benefits

* Reduces confusion about line direction.
* Improves annotation consistency for downstream models.
* Speeds up QA by making intent visually obvious.

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## Steps to Use Polyline Direction

{% stepper %}
{% step %}

#### Draw a polyline

As the polyline is drawn, arrows will indicate the direction of the line.
{% endstep %}

{% step %}

#### Verify orientation

This helps ensure correct lane flow and orientation, especially for traffic-related annotations.
{% endstep %}
{% endstepper %}

### Reverse Direction

After drawing the polyline, right-click to open the contextual menu and instantly reverse the direction. This change will be applied across the entire sequence.

### Hide Direction

Once the polyline is created, the same contextual menu lets you hide directional arrows to minimize visual clutter during annotation.

{% hint style="success" %} <img src="/files/mXHEiGg35kYjwl0I4r5p" alt="" data-size="line"> Directional arrows are automatically hidden when the annotation is not selected.
{% endhint %}