# Sandbox.SceneAnimationSystem

- Kind: class
- Namespace: `Sandbox`
- Assembly: `Sandbox.Engine`
- Inherits: [Sandbox.GameObjectSystem<T>](/api/Sandbox.GameObjectSystem<T>)
- Modifiers: sealed

## Constructors

- [`SceneAnimationSystem`](/api/Sandbox.SceneAnimationSystem/.ctor)

## Properties

- [`BoneFrame`](/api/Sandbox.SceneAnimationSystem/BoneFrame): Incremented once per frame when bones are updated. Lets per-frame bone caches - like [Sandbox.SkinnedModelRenderer.BoneWorldTransforms](/api/Sandbox.SkinnedModelRenderer/BoneWorldTransforms) - know when they're stale without re-reading the skeleton more than once per frame.