scope:

This International Standard defines the syntax and semantics of the JT Version 9.5 file format. At its core, the JT format is a scene graph with Computer Aided Design (CAD) specific node and attributes support.

The following are within scope of this International Standard:

- facet information (triangles), stored with geometry compression techniques;

- visual attributes such as lights, textures and materials ;

- product manufacturing information (PMI);

- boundary representation (b-rep) solid model shape representations and associated metadata;

- configuration representations;

- delivery methods such as asynchronous streaming of content.

The following are outside the scope of this International Standard:

- the implementation of, or definition of a run-time architecture for viewing and/or processing JT data;

- long term data retention;

- non-faceted geometric data exchange.

NOTE 1 Along with the pure syntactical definition of the format, there is also a series of conventions that, although not required to have a reference compliant JT file, have become commonplace within JT format translators. These conventions have been documented in Clause 14.

NOTE 2 Procedural shape information is included with this description for completeness. Due to the complexities of construction and interpretation of this type of data, it is advisable that more common geometry representations such as non-uniform rational b-splines (NURBS) be used in place of procedural shape information.