ANIMOD

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Description

3D animations of humanoid characters in digital games have to satisfy a great amount of requirements regarding both their visual fidelity and integration into the game context. As such, authoring unique animations for a large cast of characters creates an unfeasible spike in production cost, regardless of whether this process involves motion capture or not.

A common solution to this problem is to have these characters share the same underlying skeletal structure and proportions. This ensures that any animation created for one of those actors can be applied to all of their rigs without needing to worry about any undesirable or implausible inconsistencies in the characters’ motions.

While this workflow represents a viable approach to the animation process in the context of large productions, it inevitably causes a lack of individuality regarding characters’ body types, as well as a discrepancy between their unique personalities and styles of motion. Animation Retargeting can alleviate some of these concerns by transferring motion from one humanoid rig to other differently proportioned ones. However, because it basically just copies motions executed by one rig to another, it does not account for any kinds of differences in the style of the motion itself.

By utilizing Inverse Kinematics and other animation constraints, Animod aims to provide a procedural animation approach that is capable of both retargeting and runtime modification of humanoid animations in the Unity Game Engine, based on the IK Rig System concept pioneered by Alexander Bereznyak and Michael Buttner.

Animation Modularization and Transfer

Animod is capable of unbinding the motion defined in an Animation Clip from the Bone Rig Structure that the Clip requires to animate properly. This motion is stored as a new Animation Clip containing collections of parameters which pertain to certain parts of the Bone Rig, i.e. there is one set of parameters for each leg, one for the spine, one for each arm, etc.

Using a proper setup of Animod's Motion Constraints and the Animation post-processing capabilities of Unity's Animation Rigging package, it is possible to apply the extracted motion to Bone Rigs of differing structure.

The actual bone animation is handled by IK Solver Constraints, which use target Transforms set by the Motion Constraints to accomodate bone chains of desired link lengths.

Animation Modification