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# init(definition:nodeResourceMapping:skeletonResource:)

Compiles an animation graph definition into a resource that can drive animation on an
entity.

```
convenience init(definition: Data, nodeResourceMapping: [Int : AnimationResource] = [:], skeletonResource: SkeletonResource) throws
```

## Parameters

`definition`

The animation graph definition to compile.

`nodeResourceMapping`

A mapping from graph-node IDs to the
[`AnimationResource`](/documentation/RealityKit/AnimationResource) clips those nodes reference. Defaults to empty.

`skeletonResource`

The [`SkeletonResource`](/documentation/RealityKit/SkeletonResource) the graph targets.

## Discussion

To validate a definition without producing a resource — for example, when surfacing
errors in editor tooling — call
[`validate(definition:nodeResourceMapping:skeletonResource:)`](/documentation/RealityKit/AnimationGraphResource/validate(definition:nodeResourceMapping:skeletonResource:)) instead.

> Throws: An error if the compiler couldn’t produce a resource from the
> definition. The thrown error carries every diagnostic the compiler reported.

---

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