Difference between revisions of "iPi Biomech Add-on"

Revision as of 03:24, 19 March 2015

Note: This article is under construction and will be published in a few days. Meanwhile refer to v2 documentation: http://wiki.ipisoft.com/Biomechanical_Analysis

Introduction

iPi Biomech Add-on is a convenient tool for in-depth biomechanical analysis of human motions. It includes visualization of tracking data and its export to various formats. It can be used for:

• Export of point cloud from multiple Kinect sensors for animation or research
• Gait analysis and rehabilitation
• Sports motion analysis
• Research in 3D human kinematics

Markerless tracking technology does not require clumsy suits, and work in real-life environments like regular office.

With iPi Biomech Add-on you can:

• Get Linear and Angular Quantities for selected joints, including
  • Linear coordinate, velocity, acceleration
  • Euler angles, angular velocity and angular acceleration
  • Quaternions and Rotation matrices
• Select convenient coordinate systems
  • Linear: Absolute (relative to floor), Relative to parent joint, Relative to center of mass
  • Angular: Absolute (relative to floor), Relative to parent joint
• Select Euler angles system
• Plot values of selected Quantities for selected bones
• Export joints motion data to file
  • Tab-separated text format (for Excel)
  • MATLAB format

• Export point clouds obtained from depth sensors to file
  • MATLAB, PCD, XYZ formats convenient for research
  • Krakatoa PRT, PLY, OBJ, Leika PTS formats convenient for animation

Note: iPi Biomech Add-on requires separate license key, which you need to activate in addition to iPi Mocap Studio license key. 30-days free trial provided.

Glossary

Linear quantities

Quantities derived from linear coordinate of the joint which connects bone to it's parent bone, including:

• Coordinate
• Velocity
• Acceleration

Angular quantities

Quantities derived from bones's Euler angle, including:

• Euler angle
• Angular velocity
• Angular acceleration
• Quaternions
• Rotation matrices

Linear coordinate system

Coordinate system used for linear quantities, can be:

• Absolute (relative to ground)

• • Axes are shown by selecting Move tool;
  • Y axis is vertical
  • XZ plane is floor
  • Center and X, Z axes directions are automatically set during calibration
  • Recenter Coordinates on Character button on Scene tab before tracking will align coordinate system with actor in T-pose
    • Y is vertical axis passing through center of mass
    • XZ plane is floor
    • X is directed along left arm in T-pose
• Relative to center of mass
  • Axes directions are the same as Absolute coordinate system described above;
  • Center is in the actor model's center of mass
• Relative to parent joint
  • Axes directions are the same as Absolute coordinate system described above;
  • Center coincides with the coordinates of the parent joint

Angular coordinate system

Coordinate system used for angular quantities, can be:

• Absolute (relative to ground) — in this system rotations are defined relative to ground
• Local (Relative to parent bone) — in this system rotations are defined relative to the parent bone

Euler angles system

Set of rotations which defines Euler angles, see here

Unit

Measurement unit of physical quantity (feet or meter, etc.)

License and Trial

iPi Biomech Add-on requires separate license key, which you need to activate in addition to iPi Mocap Studio license key. You can order your license here, or activate 30-days free trial. Follow the steps below to start working with iPi Biomech Add-on

1. Switch to Biomech tab.
2. Press Activate button
3. Press Start 30-days Free Trial Period or Enter Biomech License Key and follow further on-screen instructions

   

Note: If you do not have iPi Mocap Studio license key, you can order it here or activate 30-days free trial. If your Studio trial has expired, you will not be able to export biomech data as well as animation. But you can still plot biomech data.