Several additional sources for C3D information exist – principally, the public C3D text description, and the printed documentation supplied with the commercial AMASS photogrammetry software sold by ADTech.  These both provide some basic documentation of the C3D format – the public text description being a concise ASCII specification while the printed AMASS documentation provides more of an end-user view.  Additionally, various other manufacturers implement support for the C3D file format and offer supplemental documentation to their own users. 

This manual contains several pages entitled “Notes to Programmers” which highlight specific points that are considered especially important to anyone implementing support for the C3D file format and contain the answers to many common questions.

A publicly accessible Internet web site for the C3D format is maintained at http://www.c3d.org.  This contains the most up to date copy of the current C3D format specification, together with links and contact information for any software or hardware manufacturer who wishes to be listed.  The current version of this manual, as well as other documents, are maintained on the c3d.org Internet site.

In addition to the World Wide Web site, an Internet list server is available for C3D related questions and discussions – access details for this can also be found on the C3D web site.  The web site hosts a collection of applications and files that can be downloaded via anonymous ftp service.  These include:

·      Public domain software applications that access C3D files.

·      Sample source code for reading and writing C3D files.

·      Evaluation copies of commercial software C3D applications.

·      Drivers for accessing C3D files via MATLAB and LabVIEW.

·      A free SDK for building C3D applications including sample applications with full source code in C++ and Visual Basic.

·      Sample C3D files in various formats from different manufacturers.

·      This manual in Adobe PDF formatted for printing.

·      This manual, formatted for access via any Internet browser.

A copy of the ADTech PRM program is also available from the web site together with PRMLIB, a FORTRAN library file access library, and documentation.  PRM provides the user a means of accessing the parameters in C3D and separate parameter files.  It is a command line driven MS-DOS application that operates interactively through a few simple commands and provides output to terminal screen, printer, or file.  The PRM program allows the user to create, examine, change and delete parameters in the parameter section of any C3D or ADTech parameter file.

It should be noted that the PRM utility, in common with many older C3D utilities, might have problems handling C3D files that do not strictly adhere to the original signed integer C3D standard.

Many of the examples in this manual use hex dumps to show the internal structure of the parameters.  It is worth noting that the command “SH” in the freely available ADTech command line program PRM produces a decimal dump of each byte, together with its corresponding ASCII character, of the entire parameter section.

Also available is the C3Dserver, a C3D software development kit from Motion Lab Systems, Inc., that provides high-level access to the C3D file format and works with many different programming languages and applications such as Visual Basic, C++, Java, Word, Access, and Excel etc.  The C3Dserver includes an example software application written in Visual Basic, together with full Visual Basic source code, that implements a functional C3D file editor.  A C++ application (with source code) that generated C3D files is also included.  A full manual (in Adobe PDF format) is supplied with the C3Dserver package.  This is probably the easiest way for most people to learn to access C3D files.  The C3Dserver is available free of charge for non-commercial use.

Evaluation copies of the C3Deditor and MLSviewer can also be downloaded from the C3D file site.  The C3Deditor is a graphical C3D file editor that can change and edit almost any element of the C3D file, filter data, interpolate and add or delete analog channels and 3D point information.  The MLSviewer is a general purpose C3D file viewer that displays the contents of C3D files but does not alter them in any way.  Both programs are supplied with manuals.  Information on Motion Lab Systems products is available on the Internet.

The C3D web site includes a large collection of sample C3D files from various hardware systems as well as specific sample test files that can be used to ensure that applications that you write or use are fully C3D compatible.  Copies of C3D files from various sources (including specific compatibility test files) can be downloaded from the C3D web site and the FTP site.

The C3D web site also hosts an Internet mailing list - members of the C3D mail list can send questions about specific implementations for the C3D format or requests for additional information to the C3D list server.  Anyone can join the C3D list server as membership is free – membership is only required to prevent the distribution of spam and viruses.  Instructions for joining the list can be found on the C3D web site in the Internet – http://www.c3d.org.

Copies of this document can be downloaded free of charge from the C3D web site in several different formats and redistributed with other applications at no charge subject to the agreement that is part of this manual.