Attach custom data to LowLevelPhysics2D API objects

Attach values and physics masks to physics objects so you can fetch them later.

Read time 1 minute

Last updated 10 days ago

Note

This documentation is about writing C# scripts using the

LowLevelPhysics2D

API. To use 2D physics in the Unity Editor using components like the Rigidbody 2D component, refer to 2D physics instead.

To attach custom data to an object you create using the

LowLevelPhysics2D

API, use the

PhysicsUserData

type.

You can attach data to the following types:

```
World
```
```
Body
```
```
Shape
```
```
Chain
```
```
Joint
```

Follow these steps:

Create a

PhysicsUserData

instance and populate it with your custom fields. For example:


PhysicsUserData physicsUserData = new PhysicsUserData    {        customObject = this,        customBool = true,        customFloat = 123.4f,        customInt = 567,        customPhysicsMask = PhysicsMask.All    };

Assign a
```
PhysicsUserData
```
instance to the
```
userData
```
property of the physics object. For example, to assign the custom data to a shape:
```
myShape.userData = physicsUserData;
```
To fetch the data, for example when you detect a collision, get the
```
userData
```
property of the physics object. For example:
```
Debug.Log(myShape.userData.intValue);
```

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Attach custom data to LowLevelPhysics2D API objects

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