This session shows "Helper Joints" system that is used by the game development projects in Square-Enix.

The helper joints are not actual human bones, they are many nodes that are inserted for the purpose of improving deformation quality mainly.
Over the past few years, game art has become more complex and character animation is no exception. Therefore, a lot more helper joints come to be needed, and the necessary motions are increasing too. Furthermore, we may handle the more complex motion composition in the game engine at runtime (f.e., Blending, Layering, IK, Physics).
For this reason, driving the helper joints must be solved automatically if possible.

Many artists normally construct a rig in DCC tool to drive the helper joints. In many cases till now, the complicated rig was not a thing handled in the game engine. Those logic were baked as motion data, and exported for the game engine.
Therefore we can let memory consumption by the motion data largely decrease if we handle many helper joints in the game engine. Furthermore, the quality of the motion composition at runtime improves to be able to solve automatically the helper joints. In addition, we can automatically control a material parameter (f.e., strength of the wrinkle by the normal mapping) by applying this system.

This session is intended for the artist who is interested in a technical topic. It will be shown a summary and thoughts including the mathematical topics so that an artist is easy to imagine it.