MotionBuilder uses the HIK middleware library version 2013.1.2 to perform Character solving.
The default solver is the HIK 2014 Solver. See Character Solver list menu.
Autodesk® HumanIK® animation middleware is a run-time full-body inverse kinematics (IK) solver. It is also a run-time retargeting engine for characters of differing size, proportions and skeletal hierarchy.
HumanIK offers developers a modular component for the development of their animation tool-chain and run-time game engine.
HumanIK is a highly modular, multi-threaded library, optimized for use with the following platforms:
Designed for integration into animation engines, HumanIK works in unison with third-party solvers and middleware components, such as physics and simulation engines. See Switching to HIK solving.
Following are the changes in the HumanIK 2014 Solver: