---
title: MeshJointInfluence
framework: realitykit
role: symbol
role_heading: Structure
path: realitykit/meshjointinfluence
---

# MeshJointInfluence

A binding to a joint, which consists of the joint’s index and the weight of that joint’s influence on a vertex.

## Declaration

```swift
struct MeshJointInfluence
```

## Overview

Overview A vertex may be influenced by one or more joints. The skinned position of that vertex is defined by a set of MeshJointInfluence values whose weights sum to 1. The skinned position is given by: position = vertexPosition(transformedByJoint: influences[0].jointIndex) * influences[0].weight          + vertexPosition(transformedByJoint: influences[1].jointIndex) * influences[1].weight          + ... The skinned position of a vertex is a linear combination of the vertex’s position transformed by each joint, with weights given by the MeshJointInfluence values. To transform a vertex position by a joint, the initial vertex position is first transformed by the joint’s inverse bind pose matrix, then by the local-to-parent transform of the joint, and finally by the local-to-parent transform of each of the joint’s parents.

## Topics

### Initializers

- [init()](realitykit/meshjointinfluence/init().md)
- [init(jointIndex:weight:)](realitykit/meshjointinfluence/init(jointindex:weight:).md)

### Instance Properties

- [jointIndex](realitykit/meshjointinfluence/jointindex.md)
- [weight](realitykit/meshjointinfluence/weight.md)

## See Also

### Mesh skeletons

- [MeshResource.Skeleton](realitykit/meshresource/skeleton.md)
- [MeshResource.Skeleton.Joint](realitykit/meshresource/skeleton/joint.md)
- [MeshSkeletonCollection](realitykit/meshskeletoncollection.md)
- [MeshResource.JointInfluences](realitykit/meshresource/jointinfluences.md)