This web site provides definitive information about the C3D file format for programmers, manufacturers and end-users. The C3D format is a public domain file format that has been used in Biomechanics, Animation and Gait Analysis laboratories to record synchronized 3D and analog data since the mid 1980's. It is supported by all major 3D Motion Capture System manufacturers, and companies in the Biomechanics, Motion Capture and Animation Industries. C3D files are a standard that contain all the information needed to read, display, and analyze 3D motion data with additional analog data from force plates, electromyography, accelerometers, and other sensors.
Unlike various other 3D formats (Biovision BVH files, OpenSim .TRC and .MOT files etc.,) the .C3D format is a standard that does not change each time a manufacturer releases a new product so data stored in the C3D format will remain readable for a long time. Sample files are available on this web site that were created in the mid 1990's and can be opened and processed by any C3D application.
Within this site you will find:
The C3D file format has been in continuous use since 1987. The original C3D data file format was developed by Dr. Andrew Dainis and is described in a published C3D file specification available from this web site. The C3D format was first used at the National Institutes of Health Biomechanics Laboratory in Bethesda, Maryland USA, and is now the standard 3D data storage format worldwide.
The design of the C3D file format was originally driven by the need for an accurate, and efficient format to reliably store data collected in a motion capture environment. The format stores 3D coordinate and numeric data from any measurement trial, with all the various parameters that describe the data, in a single file. This eliminates the need for motion related data to travel around with additional notes and test information (which usually gets separated from the data at some point in its travels) to be accessible.
The ability to store a multitude of information about the data is the feature that sets the C3D format apart from every other biomechanics format. Early in the design of the C3D format it was realized that it was unlikely that one, ironclad, specification would fit every biomechanics need. As a result the C3D file usually stores a small number of common parameters that describe the 3D data and then allows the users to define, generate, and store within the file any number of user or lab defined data items so that anyone opening the C3D file can access them.
As a result the C3D format is not tied to any specific manufacturer and can be freely adapted to store the information that the users require for research and general analysis and processing without making a commitment to any specific hardware environment.
This web site is designed to be easy to access and mobile friendly, with a minimum of graphics. Although maintained by Motion Lab Systems, the information provided here is not intended to push a visitor towards any specific hardware or software supplier. The only criteria for information on this site is that it is associated with the C3D format. We welcome comments and program submissions from all C3D users, equipment manufacturers and application vendors.