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Chordata documentation β

Welcome to Chordata, the free and open source motion capture system that you can build yourself.

It can be used to create low cost and highly customizable motion capture suits. Chordata relies in inertial and magnetics sensors to keep track of the changes on the body of the person wearing the sensors.

This is the Chordata knowledge base, here you can find information on the many aspect of the project, from its basic usage to the foundations that make inertial motion capture work.

If you want to dig right away with one of this topics click on one of the sections below. Or just keep reading for a review of the basic concepts behind this project.

The chordata system is in Alpha state, and we are working to complete this documentation. You might find that some parts of this wiki are still incomplete.


Chordata used on a live performance

Contents

Motivation

The field of motion capture has been receiving a lot of attention in the last few years. Not only is the scientific community creating an incredible amount of publications presenting several types of enhancements to the different techniques involved in the discipline, but also the average person with a minimum level of technological knowledge is becoming more aware of the many areas of application.

There are several reasons for this tendency. The main one might be the fact that domestic access to high computational devices has become granted to the average user. On top of that a variety of commonly available tools allow (and sometimes require) the processing of motion capture information: from 3D creation tools and video game engines, to multiple data analysis techniques.

While the cinematographic and medical industry rely on the more expensive and accurate optical capture, inertial captures are applied to situations where portability or costs are a concern. In this field the MEMS type of inertial sensor has reduced prices while increasing accuracy. Other promising techniques that require only one camera and achieve the capture through the application of Artificial intelligence algorithms are making their appearance.

We live in a historic moment when for the first time doing motion capture is (virtually) easy: all the tools to achieve it are easily available. In this scenario, the lack of a systematic guide or framework to help people implement motion capture gears draws attention. To remedy that shortcoming Chordata was developed.

Our system was specially designed to meet the following criteria:

  • Being inexpensive and easy to implement for the basic user, who is just interested in getting a capture.
  • Being flexible enough to allow an advanced user to develop a custom system, which requires implementing a motion capture solution.

Chordata is a hardware/software motion capture framework. It constitutes a starting point to begin building a new type of motion capture, one that is available to everyone and to which anyone can contribute. It also offers a launching platform in which to build and test new ideas and techniques, or deploy new discoveries in order to share them with average users beyond the academic circles.

For whom was chordata conceived

Chordata offers a fully functional motion capture system. It allows to get the movements of a performer for either using them on real time or for offline processing. It is a portable system that requires no external hardware apart from a computer or mobile computing device.

If you are interested on using motion capture on your artistic, research, or therapeutic activity, and you find that the cost of other systems are excessive, then this is the system for you.

On the other hand, even if you can afford another systems Chordata can give you a much more flexible access to the data: all the capture data is transmitted using a clear and simple protocol making the creation of custom clients a straightforward process. Moreover the system is designed to be modular and expandable, so if you need a feature that is not present at a certain time you can implement it yourself, or perhaps someone on the community has already done it.

Key features

  • Provides accurate and low latency motion capture.
  • Low cost and open hardware.
  • Free and open source software.
  • Easy setup for average captures.
  • Flexible and expandable system.
  • Adaptable to humans or other type of jointed objects and beings.

Learn how to use Chordata

Motion capture is not a simple discipline, it is often used to provide complex data that is to be processed by one or more dedicated tools. If you have no idea how the motion capture data can be used then you might probably not need a system like this one.

If you have some experience on a disciple that can benefit from the generation of motion data from a real person’s movements then on this manual you will find learning material to get you going. You will also find all the reference material necessary while using the system: wiring schemes, calibration procedures, building instructions, etc.

As you might have noticed this documentation is organized as a wiki: that type of content structure allows the documentation to constantly grow by the contribution of whoever thinks has something to say about the Chordata system, the motion capture in general or any of the many technical fields that make that discipline possible. If you want to contribute to this wiki you can learn how to do it here. Keep in mind that when you add some content to this wiki are agreeing on it being published under the Creative Commons BY-NC-SA licence.

So keep reading this manual, if you have some questions please refer to the forum and have a great time creating your own motion capture system!