User's Manual

Document MV0319P.N

MVN User Manual

12.3 C3D

C3D means “Coordinate 3D”; as the name suggests it is a file format designed to contain 3D coordinate

data, usually in the form of bony landmarks. It has also been designed to contain analog data. The 3D

and analog samples are interleaved, frame-by-frame, throughout the data in a straightforward manner.

C3D data can contain 3D, 2D, analog data or a combination. In addition, it is possible (although not very

efficient) to store the results of kinematic calculations (angles, moments, accelerations etc.) within the

3D data record format. To facilitate biomechanics users, C3D is a new export format in MVN Studio 3.0

Pro. The menu in Figure 57 shows the possibilities allowed for C3D export.

Figure 57: C3D Exporter interface in Preferences menu

There are two lists of points that can be exported, “All available points” and “External Points”. External

Points are included in the “All available” selection. Section 12.3.1 is a list of the anatomical landmarks

exported by C3D. Just like BVH, C3D data can be downsampled prior to exporting.

Most systems accept the 16 bit integer output format. However, when this is not the case, the single

precision floating point (IEEE 754) can be chosen, which will enhance resolution (less output

quantization).

In the past C3D was designed to accept no more than 65535 frames. Tick the box to allow trials longer

than 65535.

A prop will be exported in C3D with tags: ‘origin’, ‘tip’ and ‘extra’.

Exported C3Ddata has been successfully tested in C-Motion’s Visual 3D.