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# SKReachConstraints

A specification of the degree of freedom when solving inverse kinematics.

```
class SKReachConstraints
```

## Overview

An [`SKReachConstraints`](/documentation/SpriteKit/SKReachConstraints) object is used to describe the range of motion for an [`SKNode`](/documentation/SpriteKit/SKNode) object whenever an inverse kinematic (IK) action is executed. To use reach constraints, create an [`SKReachConstraints`](/documentation/SpriteKit/SKReachConstraints) object and assign it to a node’s [`reachConstraints`](/documentation/SpriteKit/SKNode/reachConstraints) property. For more information on using reach actions to perform IK animations, see the [`SKAction`](/documentation/SpriteKit/SKAction) class.

## Topics

### Working with Reach Constraints

[`init(lowerAngleLimit:upperAngleLimit:)`](/documentation/SpriteKit/SKReachConstraints/init(lowerAngleLimit:upperAngleLimit:))

Initializes a new reach constraint object.

[`lowerAngleLimit`](/documentation/SpriteKit/SKReachConstraints/lowerAngleLimit)

The minimum angle that the node can have after it is rotated by a reach event.

[`upperAngleLimit`](/documentation/SpriteKit/SKReachConstraints/upperAngleLimit)

The maximum angle that the node can have after it is rotated by a reach event.


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