Pose Editor provides a way to author secondary deformations on a MetaHuman body in Maya using RBF (radial basis function) and SwingTwist solvers. Changes are saved in a MetaHuman DNA file that can be used to conform a character in MetaHuman Creator or modify an existing MetaHuman assembly.
This guide shows how to edit poses in Maya. It assumes you have already created a character using MetaHuman Creator in Unreal Engine, and used the DCC Export assembly pipeline to export the head DNA, body DNA, and texture files.
Any changes made to the body using Pose Editor can be exported in a DNA file that can be used in Unreal Engine. Depending on the nature of the changes you have made, this file can be used with either MetaHuman Creator or directly with RigLogic. Any intermediate work can be saved as part of the current Maya scene.
Workflow Guidelines
While Pose Editor gives you the freedom to change all aspects of the body, only updates to the pose joint positions and the skinning will remain compatible with MetaHuman Creator. Any deviation in joint count, solver count, pose count, geometry topology, or swing twist count will need to be used with RigLogic directly.
This section outlines the requirements of the Maya scene that must be satisfied before exporting a DNA file. They apply to any changes that you make, regardless of whether they are compatible with MetaHuman Creator or RigLogic.
Exporting to DNA with Pose Editor supports the following components:
Skeleton
Geometry (including normals, UVs)
Skinning
RBF Solvers + Poses
Swing Twist setups
Skeleton
Skeletons are a hard requirement when exporting, it is not possible to export without one.
Only one skeleton is supported, so legacy MetaHumans that contain a driver skeleton need to be converted with the Convert Legacy MetaHuman Scene to DNA action.
DNA files do not support joint orient, nor does Unreal Engine. Joint orient is used in Maya to store the joints neutral rotation and the export process expects that when a skeleton is in the bind pose. None of the joints contain any non-joint orient rotational values. Joint names must also be unique.
The exporter will attempt to find the root joint of the skeleton using the following methods in the listed order:
Get the root joint from one of the driver joints of an RBF Solver.
Get the root joint from one of the SwingTwistEvaluator nodes.
From the current selection.
Geometry
Geometry is used to determine the LOD levels, regardless of whether export geometry is selected or not. If no geometry is present in the scene, only one LOD will be created. The process will determine:
Which geometry is tied to which LOD.
Which joints are used in each LOD.
How many influences per vertex each LOD has, based on the maximum number of influences used in the skin cluster for that LOD.
The RBF solvers used by each LOD, based on their driven joints being used by the LOD’s skin cluster.
It is best practice to organize LODs in a nesting format following the order of Geometry > Groups > Meshes, like the example below:
Naming conventions aren’t important for the groups or geometry. The export will infer that all the meshes under a specific group pertain to that LOD and the order of LODs will be in the order they appear in the outliner.
Validation
To help you understand how your changes affect compatibility, Pose Editor validates the scene before exporting the DNA file to inform you whether the output is compatible with MetaHuman Creator or RigLogic.
To validate the compatibility of your scene, use the validation buttons located on the right side of Pose Editor. These buttons provide quick feedback to inform you if your scene deviates from the requirements for MetaHuman Creator or RigLogic.
The validation button will turn red or green depending on the results, and additional information will show in the output log if necessary.
If you intend to import into MetaHuman Creator, we recommend you run the MetaHuman Creator validator as you iterate over your scene.
Importing Body DNA
Importing a body DNA file for editing with Pose Editor.
Authoring RBF
Drive the translation, rotation, and scale of a joint based on the rotation of another joint.
Authoring Swing and Twist
Use swing and twist to control corrective deformations.
Exporting DNA
Export the modified MetaHuman body DNA for use in MetaHuman Creator or with RigLogic in Unreal Engine.
Converting a Legacy MetaHuman Scene
Convert an existing MetaHuman body Maya scene to be compatible with Unreal Engine 5.6.