# Arealights

An Arealight emits light from a rectangular plane object with variable sizes. They can be used to simulate any big light sources in a rectangular shape like video walls, screens or even windows in indoor scenes. 

Additionally to a diffuse term, the Arealight also calculates a very realistic specular reflection. These reflections are f.e. very important for Video-Screens.  

<figure><img src="https://content.gitbook.com/content/SJPsyh5CBOise9BtVNGO/blobs/pxqM0s2jVfTQLzP9dngc/image.png" alt=""><figcaption><p>White Arealight </p></figcaption></figure>

### Create an Arealight

1. Place a Plane Object in your scene via Menu > Create > 3D-Objects > Plane
2. Create an Arealight Menu > Create > Lights > Arealight
3. In the 3D-Hierachy, Drop the Arealight below the Plane object \
   ![](https://content.gitbook.com/content/SJPsyh5CBOise9BtVNGO/blobs/OIUDRV2Ydv42YrasFxPN/image.png)

{% hint style="warning" %}
Arealights only work on **Plane-Objects created by Depence**. They cannot be used on imported 3D-Models.&#x20;
{% endhint %}

### Texturing

The Arealight uses the material applied to the Plane-Object for its lighting calculation. This opens many possibilities.&#x20;

<figure><img src="https://content.gitbook.com/content/SJPsyh5CBOise9BtVNGO/blobs/ekjOeiiTvkMmhiODDt0E/AreaLight.jpg" alt=""><figcaption></figcaption></figure>

### Masking

While the Arealight only works on rectangular plane objects, it is possible to use alpha masking to create other shapes.&#x20;

<figure><img src="https://content.gitbook.com/content/SJPsyh5CBOise9BtVNGO/blobs/MygIJ2RdK7gLaM2CQ4Jc/image.png" alt=""><figcaption><p>Different shapes using alpha masked textures</p></figcaption></figure>

### Limitations

{% hint style="warning" %}
Arealights are very GPU heavy! Even if they are black (f.e. due to inactive video source)! Make sure to keep them on separate layers and disable in performance critical scenarios.
{% endhint %}

{% hint style="warning" %}
Arealights actually don't cast shadows
{% endhint %}