---
title: PhysicsMassProperties
framework: realitykit
role: symbol
role_heading: Structure
path: realitykit/physicsmassproperties
---

# PhysicsMassProperties

Mass properties of a physics body.

## Declaration

```swift
struct PhysicsMassProperties
```

## Topics

### Using default mass properties

- [default](realitykit/physicsmassproperties/default.md)

### Creating custom mass properties

- [init()](realitykit/physicsmassproperties/init().md)
- [init(mass:inertia:centerOfMass:)](realitykit/physicsmassproperties/init(mass:inertia:centerofmass:).md)
- [init(shape:density:)](realitykit/physicsmassproperties/init(shape:density:).md)
- [init(shape:mass:)](realitykit/physicsmassproperties/init(shape:mass:).md)

### Getting mass properties

- [mass](realitykit/physicsmassproperties/mass.md)
- [inertia](realitykit/physicsmassproperties/inertia.md)
- [centerOfMass](realitykit/physicsmassproperties/centerofmass.md)

### Operators

- [==(_:_:)](realitykit/physicsmassproperties/==(_:_:).md)

## Relationships

### Conforms To

- [Equatable](swift/equatable.md)

## See Also

### Physical properties

- [PhysicsBodyComponent](realitykit/physicsbodycomponent.md)
- [PhysicsMaterialResource](realitykit/physicsmaterialresource.md)
- [PhysicsBodyMode](realitykit/physicsbodymode.md)