> For the complete documentation index, see [llms.txt](https://docs.overthereality.ai/over-sdk-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.overthereality.ai/over-sdk-manual/over-visual-scripting-legacy/nodes/flow/other-events/collision.md).

# Collision

### Description

This collection of [OverNode](/over-sdk-manual/over-visual-scripting-legacy/visual-scripting-essentials/overnode.md)s represents all the nodes that interact with the physics Unity Collision system.

#### Collision Node

The main element of this collection consists of a Collision Node, that fires its execution on detecting a specific Collision event.

Each Collision Node must refer to a specific `Target` GameObject, accordingly equipped with a Unity [Collider](https://docs.unity3d.com/ScriptReference/Collider.html) Component. Once a collision is detected, the following nodes will be executed.

A `Mode` parameter can be selected in order to further customize the execution of the node, specifically:

<table><thead><tr><th width="204">Name</th><th>Description</th></tr></thead><tbody><tr><td>Enter</td><td>Sets the node to be executed when a physical object enters the Target Collider space</td></tr><tr><td>Stay</td><td>Sets the node to be executed when a physical object stays inside the Target Collider space</td></tr><tr><td>Exit</td><td>Sets the node to be executed when a physical object exits the Target Collider space</td></tr></tbody></table>

The Node also exposes some parameters, also describing the Collision itself:

<table><thead><tr><th width="205.7659040188865">Name</th><th width="194.3279424240331">Type</th><th width="340.1572968009442">Description</th></tr></thead><tbody><tr><td>Other</td><td><a href="https://docs.unity3d.com/ScriptReference/Collider.html">Collider</a></td><td>A reference of the input Unity Collider Component of the object colliding with the Target</td></tr><tr><td>Contacts</td><td>ContactPoint [ ]</td><td>List of contact points where the collision occurs</td></tr><tr><td>Impulse</td><td>Vector3</td><td>The total impulse applied to this contact pair to resolve the collision</td></tr><tr><td>Relative Velocity</td><td>Vector3</td><td>The relative linear velocity of the two colliding objects (Read Only)</td></tr></tbody></table>

<figure><img src="/files/8miScSgStNfFkHfFatMF" alt=""><figcaption></figcaption></figure>

#### OverCollisionListener

In order for the Node system to communicate with the Unity Runtime environment, a OverCollisionListener component must be associated with the Target GameObject.&#x20;

Its main function is to provide a bridge between the node system and the UnityEngine event system, which handles collision events automatically.

<figure><img src="/files/awBIQilj2dJkGRhrnAYd" alt=""><figcaption></figcaption></figure>

#### Collider Exposer

This node is used to expose certain parameters and attributes of a given input Unity [Collider](https://docs.unity3d.com/ScriptReference/Collider.html) Component, which are:

<table><thead><tr><th>Name</th><th width="204.3279424240331">Type</th><th width="340.1572968009442">Description</th></tr></thead><tbody><tr><td>Ref</td><td><a href="https://docs.unity3d.com/ScriptReference/Collider.html">Collider</a></td><td>A reference of the input Unity Collider Component</td></tr><tr><td>Object</td><td><a href="https://docs.unity3d.com/ScriptReference/GameObject.html">GameObject</a></td><td>GameObject associated to the collider</td></tr></tbody></table>

<figure><img src="/files/3E0wVYqqtrWKKAusir1c" alt=""><figcaption></figcaption></figure>