---
title: "automatchBiped(_:to:jointOffsets:)"
framework: realitykit
role: symbol
role_heading: Type Method
path: "realitykit/retargetingconfiguration/automatchbiped(_:to:jointoffsets:)"
---

# automatchBiped(_:to:jointOffsets:)

Creates a retargeting configuration for bipedal characters using automatic joint matching.

## Declaration

```swift
@MainActor static func automatchBiped(_ sourceSkeleton: SkeletonResource, to targetSkeleton: SkeletonResource, jointOffsets: [String : simd_quatf] = [:]) throws -> RetargetingConfiguration
```

## Parameters

- `sourceSkeleton`: The skeleton of the animation to retarget.
- `targetSkeleton`: The skeleton that will receive the re-targeted animation.
- `jointOffsets`: Optional quaternion offsets applied to specific joints during configuration creation. Keys must match joint names in the target skeleton. The function applies offsets on top of the automatically detected joint correspondences and bakes them into the configuration.

## Return Value

Return Value A configured retargeting instance ready for animation processing.

## Discussion

Discussion This method uses an automatic matching algorithm to analyze both skeletal hierarchies and establish correspondences between key joints. The algorithm performs joint identification to locate required anatomical landmarks and generates a retargeting configuration accordingly. Required Joints The algorithm identifies and requires the following joints in both skeletons: Core: Hips, Spine Base, Chest, Neck Base, Head Arms: Left/Right Shoulder, Upper Arm, Elbow, Wrist Legs: Left/Right Upper Leg, Knee, Ankle, Toe Optional Joints The algorithm can optionally identify and use: Toe End joints (Left/Right Toe End) Finger Base joints (Left/Right Finger Base 0-4) Algorithm Behavior Performs automatic joint identification using joint names and hierarchical structure. Supports T-pose and A-pose configurations. May optimize the resulting configuration by culling unnecessary joints. Applies joint offsets on top of automatically detected correspondences during configuration creation. Example do {     // Basic biped retargeting     let config = try RetargetingConfiguration.automatchBiped(         humanoidSourceSkeleton,         to: humanoidTargetSkeleton     )

// With joint adjustments     let jointOffsets: [String: simd_quatf] = [         "LeftShoulder": simd_quatf(angle: .pi / 18, axis: simd_float3(0, 0, 1)),         "RightWrist": simd_quatf(angle: -.pi / 36, axis: simd_float3(1, 0, 0))     ]     let refinedConfig = try RetargetingConfiguration.automatchBiped(         humanoidSourceSkeleton,         to: humanoidTargetSkeleton,         jointOffsets: jointOffsets     ) } catch {     print("Failed to create retargeting configuration: \(error.localizedDescription)") } note: An error if configuration creation fails. All errors provide descriptive messages via their localizedDescription property. Common failures include: A joint offset was specified for a joint name that doesn’t exist in the target skeleton. The algorithm could not identify required joints in one or both skeletons. Joint identification or rig generation failed.

## See Also

### Creating a configuration

- [automatchBiped(_:sourceTransform:to:targetTransform:jointOffsets:)](realitykit/retargetingconfiguration/automatchbiped(_:sourcetransform:to:targettransform:jointoffsets:).md)
- [automatchQuadruped(_:sourceTransform:to:targetTransform:jointOffsets:)](realitykit/retargetingconfiguration/automatchquadruped(_:sourcetransform:to:targettransform:jointoffsets:).md)