The NFF standard is can accomodate file formats that are indigenous to various platforms with a minimum of effort. Sense8 has a file conversion program to bring DXF files into NFF format. They are putting this specification into the public domain. Thus, the NFF format serves as in interface between modellers which cannot write geometry in any of the forms accepted by WorldToolKit. In the NFF file format, objects are represented as sets of polygons, and polygons are ordered collections of vertices.
Polygons have colors and can optionally have other attributes specified.
Objects can optionally be named. There follows an optional viewpoint specification associated with the file, and a set of one or more object specifications. By default, an NFF file containing more than one object will load as a single object, which contains all of the file's objects. Each object specification start with a line of text giving the object's symbolic name. The next line contains the number of vertices in the object.