Rigging Tool

Meta Echo

Automated facial rigging from MetaHuman to custom characters. Meta Echo helps developers without rigging or animation expertise transfer high-quality facial performance to stylized characters and drive them through Unreal Live Link.

Python Maya RBF MetaHuman Unreal Live Link

View Code on GitHub

Problem

MetaHuman delivers strong facial performance through Live Link, but most developers cannot manually key high-quality facial animation. Traditional facial rigging is difficult, slow, and requires specialized rigging or animation skills.

Solution

Meta Echo connects cartoon and custom characters to MetaHuman-style facial rigs. The tool automates the core rigging workflow so a developer can quickly generate facial joints, transfer weights, constrain the new skeleton, and use MetaHuman animation data to drive the target character.

Meta Echo facial rigging result on a custom character.

Core Method

RBF-Based Retargeting

The core engine is based on Radial Basis Function interpolation, inspired by the SIGGRAPH 2000 paper Pose Space Deformation. Unlike simple linear rigging, RBF supports non-linear deformation, which is important for facial expressions because face motion is curved, complex, and topology dependent.

In Meta Echo, the RBF solver acts as a mathematical bridge between the MetaHuman source mesh and a custom target mesh. It builds a mapping matrix that helps transfer rigging structure and animation behavior across different facial proportions and mesh topologies.

Meta Echo RBF tool interface — RBF solver and retargeting tool interface.

Workflow

Automated Rigging Pipeline

1. Load Source and Target

Load the original MetaHuman head as the source and the custom cartoon face as the target.

2. Build Solver

Generate the RBF mapping matrix that bridges the source and target meshes.

3. Retarget Skeleton

Select the source skeleton and target mesh, then generate new joints that fit the custom character.

4. Bind and Copy Skin Weights

Bind the target mesh to the generated joints and transfer professional MetaHuman skin weight data.

5. Joint Constraint

Connect MetaHuman animation data to the generated skeleton through constraint logic.

6. Drive with Live Link

Use the GUI panel or Unreal Live Link Control Rig data to drive the cartoon character with synced facial animation.

Environment

Requirements and Usage

Autodesk Maya with Python support
Python packages: numpy, scipy
MetaHuman source project
Unreal Engine Live Link facial animation workflow

import metaEcho_RunTool

tool = metaEcho_RunTool.MetaEchoFullToolbox()
tool.show()