Skeleton Structure

The basis of the skeleton structure is the same as the structure of Unity Humanoid Rig. It looks as follows:

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/aaf899dd-ffa9-4919-858b-db732e58b2b8/Untitled.png

Unnecessary bones are shown in square brackets. For example, Root bone is being created so that the skeleton would support Root motion, while LeftBreast and RightBreast meant for animating female breasts.

This hierarchy can be supplemented by the arbitrary amount of additional bones if the following conditions are met:

  1. Skeleton has all the mandatory bones;
  2. Additional bones do not change the hierarchical subordination of mandatory ones.

General Rules for Bones Naming

Upon the creation of additional bones it is recommended to name them according to the following rules:

  1. Names are written without underscores, every word starts with a capital letter;
  2. Words that specify the relative position of bones are written in "from bigger to lesser" order (e.g. upper wing, located on the left part of the character, should be named as LeftUpperWing).

Initial Pose and Bones Orientation

Skeleton's initial pose is considered to be a T-pose (the character stands straight and looks forward, legs are paralleled with each other, arms are spread sidewise and paralleled with the horizon, all joints are straightened, palms look downwards, thumbs are bent sideways at the 45 degrees angle).

Initial orientation of axes of all bones correlates with the orientation of axes of global coordinates (i.e. Y axis (height) always goes upwards, while Z axis (depth) always goes forwards). General direction of thumbs' axes remains the same and orients along the phalanx, as shown below:

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/44b8c6e6-80f3-459c-b835-baa90761da41/Untitled.png

Standard Measures for Characters

The character can have arbitrary sizes and proportions, but to guarantee the compatibility of the character with the instruments and systems (e.g. with the instrument of ragdoll automatic adjustment or the equipment system), it is recommended to use the accepted base models for both male and female characters as references. Base models can be found in the project folder that corresponds to this Standard.