# Areas of Interest

## LiveQueries

The way Clients get information about the world is through **LiveQueries**. They are a tool to specify what part of the world a Client is interested in at each given moment: in other words, they define an **area of interest**. That way, the Replication Server won’t send information about everything that is going on in the Game World everywhere, at all times.

Instead, they will just get information about what’s within a certain area, kind of like moving a torch to look around in a dark cave.

{% hint style="danger" %}
Using LiveQueries is **compulsory**! Without **at least one LiveQuery** in the scene, no entities will be updated.
{% endhint %}

### Adding a LiveQuery to the scene

<figure><img src="https://352971571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOnNWMLfYsbCzCnIbNrcP%2Fuploads%2FygYueBeV4NTyUe9jK8kp%2Fadd-live-query.png?alt=media&#x26;token=469af5d4-3eba-44de-9970-20005f6d1831" alt=""><figcaption></figcaption></figure>

A LiveQuery is a cube that defines the area of interest in a particular part of the World. It is defined by its **position** and its **extent** (half the side of the cube). There can be multiple LiveQueries in a single scene.

![](https://352971571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOnNWMLfYsbCzCnIbNrcP%2Fuploads%2FRPN2wUwa1IPClstMdmen%2Fimage.png?alt=media)

### Moving a LiveQuery

A classic approach is to put a LiveQuery on the camera and set the extent to correspond to the far clipping plane or visibility distance.

Moving the GameObject containing the LiveQuery will also notify the Replication Server that the query for that particular Game Client has moved.

## TagQueries

In addition to the LiveQuery, **coherence** also supports defining interest with tags. This is useful when you have some special objects that should always be visible regardless of their position.

To add a `TagQuery`, simply add it to a GameObject like any regular component.

![](https://352971571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOnNWMLfYsbCzCnIbNrcP%2Fuploads%2FQOAAPdFttx8Pm8grnnK1%2FTagQuery.png?alt=media\&token=c614c2eb-5f3c-4d46-ab79-1f08f136a466)

All networked GameObjects with matching tags will now be visible to the Client. This **coherence** tag is not related to the Unity concept of [Tags](https://docs.unity3d.com/Manual/Tags.html), and can be a string of any value. It can be configured in the *Advanced Settings* section of the `CoherenceSync` component.

![](https://352971571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FOnNWMLfYsbCzCnIbNrcP%2Fuploads%2F40czlUwAkBaqqbRGZjRC%2FAdvancedSettings_Tag.png?alt=media\&token=336ebf4f-2a6b-4a0b-a5b0-1a38bbf2d941)

Object tags and the tag requested by a `TagQuery` can be updated at any time while the application is running, either from the Unity Inspector or by setting `CoherenceSync.coherenceTag` and `CoherenceTagQuery.coherenceTag` with code.

Currently, only one single tag per GameObject and TagQuery is supported.

To include objects with different tags, you can create multiple TagQuery objects for each tag.

{% hint style="info" %}
In the future, we plan to integrate TagQueries with LiveQueries allowing combined query restrictions, e.g., only show objects with tag "red" within an extent of 50.
{% endhint %}

{% hint style="success" %}
Queries can also be used for cheat prevention, see [Server authoritative setup](https://docs.coherence.io/1.0/coherence-sdk-for-unity/authority-overview/input-queues) for more information.
{% endhint %}