# New Animation Library

The **Scriptable Animation System** is a complex technology, which brings not just a single plugin, but a new way to organize, manage and extend the functionality of animation features in your game.

Let's start with a new **KAnimationCore** plugin, which adds a solid low-level library of animation functions and types.

<figure><img src="https://784345943-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FxcUmJ78NSw1bSUlSO9oP%2Fuploads%2FPwe31mGno87JV48SbQAT%2Fimage.png?alt=media&#x26;token=03cbe436-d3ca-4b61-a98c-4284d7142927" alt="" width="269"><figcaption></figcaption></figure>

## KAnimationMath

This class includes static functions to manipulate transforms in real time. It essentially replaces the **CoreToolkitLib** from the previous version. The only difference is that **KAnimationMath** is responsible for animation functions only.

## KCurves

Includes everything related to the curves in the framework. This includes new curve types and easing functions.

## KMath

A new library designed for general math operations.

## KSpringMath

This class implements runtime spring computation. You can use it if you wish to add a spring interpolation to your feature.

## KTransform

This is a struct that is identical to the Unity built-in Transform type. The only difference is that it is a struct, which means we can use it safely in Unity Jobs!

This struct has all the methods to manipulate the transform:

```csharp
public static KTransform Lerp(KTransform a, KTransform b, float alpha)

// Frame-rate independent interpolation.
public static KTransform ExpDecay(KTransform a, KTransform b, float speed, float deltaTime)

public bool Equals(KTransform other, bool useScale)

// Returns a point relative to this transform.
public Vector3 InverseTransformPoint(Vector3 worldPosition, bool useScale)

// Returns a vector relative to this transform.
public Vector3 InverseTransformVector(Vector3 worldDirection, bool useScale)

// Converts a local position from this transform to world.
public Vector3 TransformPoint(Vector3 localPosition, bool useScale)

// Converts a local vector from this transform to world.
public Vector3 TransformVector(Vector3 localDirection, bool useScale)

// Returns a transform relative to this transform.
public KTransform GetRelativeTransform(KTransform worldTransform, bool useScale)

// Converts a local transform to world.
public KTransform GetWorldTransform(KTransform localTransform, bool useScale)
```

## KPose

KPose defines how the selected element will be modified in real time. It is often used by Animator Layers, but you can also find it useful for other applications:

<figure><img src="https://784345943-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FxcUmJ78NSw1bSUlSO9oP%2Fuploads%2FoXQDOFlJHdKpz46qHHZz%2Fimage.png?alt=media&#x26;token=de2dc0b0-4da3-4ae6-bffe-74c7472effbe" alt="" width="377"><figcaption><p>KPose Example.</p></figcaption></figure>

**Element** defines the bone/element that will be modified, and Pose is a KTransform that represents the value.

**Space** defines where our applications will be done. So far the system supports:

* **Bone space**: the space of the element's current frame.
* **Parent Bone** **space**: the space of the parent bone.
* **Component space**: the space of the character root bone.
* **World space**: the global space, a standard world space.

**Modify Mode** defines how the Pose will be applied:

* **Add**: the Pose will be added to the element.
* **Replace**: the Pose will replace the element's transform.

## KTwoBoneIK

This class implements a two-bone IK algorithm, which is Unity Jobs-friendly! The Solve function uses **KTransform** by default and also provides a **KTwoBoneIkJob** class to solve inverse kinematics for multiple limbs in ParallelFor.

By default, this class is used in the **IkLayerState** class to apply inverse kinematics.

As you can see, the new **KAnimationUtilty** is a way more streamlined, and most importantly independent from the main code-based, which makes it possible to use outside of the framework.

In the next section, we will learn more about the **KRig** assets.