There are currently three available models in Theia3D:

1. Default Model
   • Consists of two kinematic chains: lower body (pelvis and legs) and upper body (torso, arms, and head).
   • No abdomen or neck segments.
   • Shoulder joints and head segment are allowed 6 degrees of freedom.

2. Separate Arm and Head Model
   • Consists of five kinematic chains: lower body (pelvis and legs), torso, left arm, right arm, and head.
   • No abdomen or neck segments.
   • Shoulder joints and head segment are allowed 6 degrees of freedom.

3. Full Body Model
   1. Consists of one, whole-body kinematic chain.
   2. Abdomen and neck segments included.
   3. Shoulder joints are allowed 6 degrees of freedom.
   4. Head is allowed 3 degrees of freedom.