What is Rig Transfer?

Rig Transfer is the process of transferring a bone-based rig from a template asset to a target asset, assuming both share the same topology. This process utilizes a 3D spatial transformation model to reposition and reorient the bones of the target asset, ensuring the rig is correctly aligned. The transformation is guided by user-defined structural constraints that preserve the integrity of the rig, such as maintaining parent-child bone relationships, enforcing bone coplanarity and collinearity, and respecting the positioning of frozen bones.

Rig transfer allows for the efficient adaptation of rigs to new assets, facilitating faster asset creation while maintaining consistent, realistic movements and deformations across different models.

Use in Popul8

The Rig Transfer feature will enable the user to import non-rigged characters in Popul8, convert them to Shapes, and turn them into an animatable characters.

When the feature is made available, the user will be able to right-click on a template Shape to create a Rig Transfer asset, which will have user configurable settings:

• Deformer type: fast / accurate, describing the underlying spatial transformation model used to reposition and reorient bones.
• Bone constraints, the various bone constraints to be applied to the retargeted rig to preserve its integrity and compliance with the intended animation system:
  • Immutable bones: the list of bones whose global transformations are kept unchanged with respect to the template.
  • Frozen bones: list of bones whose local transformations are kept unchanged with respect to the template.
  • Coplanarity groups: list of bone groups submitted to coplanarity constraints, i.e., all bones from the group should lie on the same plane.
  • Colinearity groups: list of bone groups submitted to colinearity constraints, i.e., all bones from the group should lie on the same line.

After editing the settings, the user will click on Apply Changes to trigger the rig transfer process.