13. Model Reference¶
There are currently three available models in Theia3D:
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.
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.
Full Body Model
Consists of one, whole-body kinematic chain.
Abdomen and neck segments included.
Shoulder joints are allowed 6 degrees of freedom.
Head is allowed 3 degrees of freedom.
13.1. Pose¶
Model pose can be exported to .c3d, .fbx, and .json files.
The .c3d files contain the 4x4 pose matrices for each model segment and the local coordinates of the anatomical landmarks of the distal segments of the model (feet, hands, head). These files can be processed using Visual3D.
The .fbx files contain the hierachical skeleton, pose, and bone meshes of the animation model. The first frame of the file contains the model in a “T-Pose”. The skeleton must be solved using the Full Body Model in order to save pose files in FBX format.
The .json files contain information about how the trial was processed (Theia3D version, model, preferences, etc.) and the 4x4 pose matrices for each body segment for every frame of the trial.
The Theia3D kinematic model, shown as 3D segments in the Theia3D viewer.
13.2. Default Model Description¶
The Default kinematic model consists of two kinematic chains for the lower body (pelvis and legs) and upper body (torso, arms, and head).
Torso |
Parent: Lab
Origin: Base of neck
Joint: Free joint (6 DOF)
|
Head |
Parent: Torso
Origin: Midpoint of ears
Joint: Free joint (6 DOF)
|
Right Upper Arm |
Parent: Torso
Origin: Right shoulder
Joint: Free joint (6 DOF)
Proximal: Right shoulder
Distal: Right elbow
|
Right Lower Arm |
Parent: Right upper arm
Origin: Right elbow
Joint: Two rotational degrees of freedom (flexion/extension, pronation/supination)
Proximal: Right elbow
Distal: Right wrist
|
Right Hand |
Parent: Right lower arm
Origin: Right wrist
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction)
Proximal: Right wrist
Distal: Right mid hand
|
Left Upper Arm |
Parent: Torso
Origin: Left shoulder
Joint: Free joint (6 DOF)
Proximal: Left shoulder
Distal: Left elbow
|
Left Lower Arm |
Parent: Left upper arm
Origin: Left elbow
Joint: Two rotational degrees of freedom (flexion/extension, pronation/supination)
Proximal: Left elbow
Distal: Left wrist
|
Left Hand |
Parent: Left lower arm
Origin: Left wrist
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction)
Proximal: Left wrist
Distal: Left mid hand
|
Pelvis |
Parent: Lab
Origin: Midpoint of pelvis plane
Joint: Free joint (6 DOF)
|
Right Thigh |
Parent: Pelvis
Origin: Right hip
Joint: Three rotational degrees of freedom
Proximal: Right hip
Distal: Right knee
|
Right Shank |
Parent: Right thigh
Origin: Right knee
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction) or three rotational degrees of freedom (flexion/extension, ad/abduction, internal/external rotation)
Proximal: Right knee
Distal: Right ankle
|
Right Foot |
Parent: Right shank
Origin: Right ankle
Joint: Free joint (6 DOF), with limited translation
Proximal: Right ankle
Distal: Right mid foot
|
Right Toes |
Parent: Right foot
Origin: Right mid foot
Joint: One rotational degree of freedom (flexion/extension)
Proximal: Right mid foot
Distal: Right big toe
|
Left Thigh |
Parent: Pelvis
Origin: Left hip
Joint: Three rotational degrees of freedom
Proximal: Left hip
Distal: Left knee
|
Left Shank |
Parent: Left thigh
Origin: Left knee
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction) or three rotational degrees of freedom (flexion/extension, ad/abduction, internal/external rotation)
Proximal: Left knee
Distal: Left ankle
|
Left Foot |
Parent: Left shank
Origin: Left ankle
Joint: Free joint (6 DOF), with limited translation
Proximal: Left ankle
Distal: Left mid foot
|
Left Toes |
Parent: Left foot
Origin: Left mid foot
Joint: One rotational degree of freedom (flexion/extension)
Proximal: Left mid foot
Distal: Left big toe
|
13.3. Separate Arm and Head Model Description¶
The Separate Arm and Head kinematic model consists of five kinematic chains for the lower body (pelvis and legs), torso, left arm, right arm, and head. Use of this model allows the separate chains that make up the upper body to be tracked when other upper body chains are lost.
Torso |
Parent: Lab
Origin: Base of neck
Joint: Free joint (6 DOF)
|
Head |
Parent: Lab
Origin: Midpoint of ears
Joint: Free joint (6 DOF)
|
Right Upper Arm |
Parent: Lab
Origin: Right shoulder
Joint: Free joint (6 DOF)
Proximal: Right shoulder
Distal: Right elbow
|
Right Lower Arm |
Parent: Right upper arm
Origin: Right elbow
Joint: Two rotational degrees of freedom (flexion/extension, pronation/supination)
Proximal: Right elbow
Distal: Right wrist
|
Right Hand |
Parent: Right lower arm
Origin: Right wrist
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction)
Proximal: Right wrist
Distal: Right mid hand
|
Left Upper Arm |
Parent: Lab
Origin: Left shoulder
Joint: Free joint (6 DOF)
Proximal: Left shoulder
Distal: Left elbow
|
Left Lower Arm |
Parent: Left upper arm
Origin: Left elbow
Joint: Two rotational degrees of freedom (flexion/extension, pronation/supination)
Proximal: Left elbow
Distal: Left wrist
|
Left Hand |
Parent: Left lower arm
Origin: Left wrist
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction)
Proximal: Left wrist
Distal: Left mid hand
|
Pelvis |
Parent: Lab
Origin: Midpoint of pelvis plane
Joint: Free joint (6 DOF)
|
Right Thigh |
Parent: Pelvis
Origin: Right hip
Joint: Three rotational degrees of freedom
Proximal: Right hip
Distal: Right knee
|
Right Shank |
Parent: Right thigh
Origin: Right knee
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction) or three rotational degrees of freedom (flexion/extension, ad/abduction, internal/external rotation)
Proximal: Right knee
Distal: Right ankle
|
Right Foot |
Parent: Right shank
Origin: Right ankle
Joint: Free joint (6 DOF), with limited translation
Proximal: Right ankle
Distal: Right mid foot
|
Right Toes |
Parent: Right foot
Origin: Right mid foot
Joint: One rotational degree of freedom (flexion/extension)
Proximal: Right mid foot
Distal: Right big toe
|
Left Thigh |
Parent: Left
Origin: Left hip
Joint: Three rotational degrees of freedom
Proximal: Left hip
Distal: Left knee
|
Left Shank |
Parent: Left thigh
Origin: Left knee
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction) or three rotational degrees of freedom (flexion/extension, ad/abduction, internal/external rotation)
Proximal: Left knee
Distal: Left ankle
|
Left Foot |
Parent: Left shank
Origin: Left ankle
Joint: Free joint (6 DOF), with limited translation
Proximal: Left ankle
Distal: Left mid foot
|
Left Toes |
Parent: Left foot
Origin: Left mid foot
Joint: One rotational degree of freedom (flexion/extension)
Proximal: Left mid foot
Distal: Left big toe
|
13.4. Full Body Model Description¶
The full body kinematic model consists of one kinematic chain comprised of the lower body, upper body, and head, with the pelvis as the root segment. Abdomen and neck segments are included. The Full Body Model must be used in order to save skeleton poses as FBX format.
Pelvis |
Parent: Lab
Origin: Midpoint of pelvis plane
Joint: Free joint (6 DOF)
|
Abdomen |
Parent: Pelvis
Origin: Pelvis origin
Joint: Two rotational degrees of freedom (flexion/extension, abduction/adduction)
|
Torso |
Parent: Abdomen
Origin: Base of neck
Joint: Three rotational degrees of freedom, one translational degree of freedom (along Z)
|
Neck |
Parent: Torso
Origin: Base of neck
Joint: Three rotational degrees of freedom
|
Head |
Parent: Neck
Origin: Midpoint of ears
Joint: Three rotational degrees of freedom
|
Right Upper Arm |
Parent: Torso
Origin: Right shoulder
Joint: Free joint (6 DOF)
Proximal: Right shoulder
Distal: Right elbow
|
Right Lower Arm |
Parent: Right upper arm
Origin: Right elbow
Joint: Two rotational degrees of freedom (flexion/extension, pronation/supination)
Proximal: Right elbow
Distal: Right wrist
|
Right Hand |
Parent: Right lower arm
Origin: Right wrist
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction)
Proximal: Right wrist
Distal: Right mid hand
|
Left Upper Arm |
Parent: Torso
Origin: Left shoulder
Joint: Free joint (6 DOF)
Proximal: Left shoulder
Distal: Left elbow
|
Left Lower Arm |
Parent: Left upper arm
Origin: Left elbow
Joint: Two rotational degrees of freedom (flexion/extension, pronation/supination)
Proximal: Left elbow
Distal: Left wrist
|
Left Hand |
Parent: Left lower arm
Origin: Left wrist
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction)
Proximal: Left wrist
Distal: Left mid hand
|
Right Thigh |
Parent: Pelvis
Origin: Right hip
Joint: Three rotational degrees of freedom
Proximal: Right hip
Distal: Right knee
|
Right Shank |
Parent: Right thigh
Origin: Right knee
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction) or three rotational degrees of freedom (flexion/extension, ad/abduction, internal/external rotation)
Proximal: Right knee
Distal: Right ankle
|
Right Foot |
Parent: Right shank
Origin: Right ankle
Joint: Free joint (6 DOF), with limited translation
Proximal: Right ankle
Distal: Right mid foot
|
Right Toes |
Parent: Right foot
Origin: Right mid foot
Joint: One rotational degree of freedom (flexion/extension)
Proximal: Right mid foot
Distal: Right big toe
|
Left Thigh |
Parent: Left
Origin: Left hip
Joint: Three rotational degrees of freedom
Proximal: Left hip
Distal: Left knee
|
Left Shank |
Parent: Left thigh
Origin: Left knee
Joint: Two rotational degrees of freedom (flexion/extension, ad/abduction) or three rotational degrees of freedom (flexion/extension, ad/abduction, internal/external rotation)
Proximal: Left knee
Distal: Left ankle
|
Left Foot |
Parent: Left shank
Origin: Left ankle
Joint: Free joint (6 DOF), with limited translation
Proximal: Left ankle
Distal: Left mid foot
|
Left Toes |
Parent: Left foot
Origin: Left mid foot
Joint: One rotational degree of freedom (flexion/extension)
Proximal: Left mid foot
Distal: Left big toe
|