ISO 14306-3:2025

Industrial automation systems and integration — JT file format specification for 3D visualization — Part 3: Version 2

This document defines the syntax and semantics of a file format for the 3D visualization and interrogation of lightweight geometry and product manufacturing information derived from CAD systems, using visualization software tools that do not need the full capability of a CAD system. This document has been adopted as a 3D visualization capability in addition to the ISO 10303 series. The ISO 10303 series are the ISO standards adopted for the engineering data exchange, sharing and long-term archiving of product definition information throughout the product lifecycle. In this document 3D visualization is defined as the visual presentation on a screen or another media of graphical and textual 3 dimensional representations of a set of data representing an object, information or results of a computational process in order to enable decision process by a human looking at the data visualized in a medium. The file format supports the following information: — facet information (triangles), stored with geometry compression techniques; — visual attributes such as lights, textures and materials; — product manufacturing information, such as dimensions, tolerances and other attributes; — boundary representation (b-rep) solid model shape representations. Several alternatives are available, including a representation based on the geometry standard defined in ISO 10303; — configuration representations; — delivery methods such as asynchronous streaming of content. The document does not specify the implementation of, or definition of a run-time architecture for viewing or processing of the file format.

Systèmes d'automatisation industrielle et intégration — Spécification de format de fichier JT pour visualisation 3D — Partie 3: Titre manque

General Information

• Status: Published
• Publication Date: 24-Jun-2025
• ICS: 25.040.01 - Industrial automation systems in general
• Technical Committee: ISO/TC 184/SC 4 - Industrial data
• Drafting Committee: ISO/TC 184/SC 4/JWG 16 - Joint ISO/TC 184/SC 4 - ISO/IEC JTC 1/SC 24 - ISO/TC 171/SC 2 WG: Formats for visualization and other derived forms of product data
• Current Stage: 6060 - International Standard published
• Start Date: 25-Jun-2025
• Due Date: 17-Dec-2025
• Completion Date: 25-Jun-2025

Relations

• Revises: ISO 14306:2017 - Industrial automation systems and integration — JT file format specification for 3D visualization
• Effective Date: 07-Jan-2025

Standards Content (Sample)

International
Standard
ISO 14306-3
First edition
Industrial automation systems
2025-06
and integration — JT file format
specification for 3D visualization —
Part 3:
Version 2
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword . vi
Introduction . viii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 2
4 Notational conventions . 3
4.1 Diagrams and field descriptions . 3
4.2 Data Types . 8
4.3 Empty field . 11
5 File Format . 12
5.1 General File Format . 12
5.2 File Structure . 12
5.2.1 File Header . 12
5.2.2 TOC Segment . 14
5.2.3 Data Segment . 16
5.3 Logical Element Header ZLIB . 20
5.4 Data Segments . 21
6 LSG Segment . 23
6.1 LSG Data Collection . 23
6.2 Graph Elements . 23
6.2.1 Node Elements. 24
6.2.2 Attribute Elements. 49
6.3 Property Atom Elements . 93
6.3.1 Base Property Atom Element . 93
6.3.2 String Property Atom Element . 94
6.3.3 Integer Property Atom Element . 95
6.3.4 Floating Point Property Atom Element . 96
6.3.5 JT Object Reference Property Atom Element . 96
6.3.6 Date Property Atom Element . 97
6.3.7 Late Loaded Property Atom Element . 99
6.3.8 Vector4f Property Atom Element . 100
6.4 Property Table . 101
6.4.1 Element Property Table . 102
7 Shape LOD Segment . 103
7.1 General Shape Lod Segment . 103
7.2 Shape LOD Element . 103
7.2.1 Base Shape LOD Element . 103
7.2.2 Vertex Shape LOD Element. 104
7.2.3 Tri-Strip Set Shape LOD Element . 119
7.2.4 Polyline Set Shape LOD Element . 119
7.2.5 Point Set Shape LOD Element . 120
7.2.6 Null Shape LOD Element . 121
7.3 Primitive Set Shape Element . 121
7.3.1 Lossless Compressed Primitive Set Data . 123
7.3.2 Lossy Quantized Primitive Set Data . 125
iii
8 Geometry Segments . 130
8.1 General Geometry Segments . 130
8.2 STEP B-Rep Segment . 130
8.3 XT B-Rep Segment . 130
8.4 JT ULP Segment . 130
8.5 JT LWPA Segment . 130
8.6 Wireframe Segment . 130
8.7 JT B-Rep Element (deprecated) . 131
9 Meta Data Segment . 132
9.1 General Meta Data Segment . 132
9.2 Property Proxy Meta Data Element . 132
9.2.1 Date Property Value . 134
9.3 PMI Manager Meta Data Element . 135
9.3.1 PMI Entities . 138
9.3.2 PMI Associations. 160
9.3.3 PMI User Attributes . 162
9.3.4 PMI String Table . 163
9.3.5 PMI Model Views . 164
9.3.6 Generic PMI Entities . 166
9.3.7 PMI CAD Tag Data . 171
9.3.8 PMI Polygon Data . 173
10 Data Compression and Encoding. 177
10.1 General Data Compression and Encoding . 177
10.2 Common Compression Data Collection Formats . 177
10.2.1 Int32 Compressed Data Packet . 177
10.2.2 Int32 Compressed Data Packet Mk. 2 . 183
10.2.3 Float64 Compressed Data Packet . 189
10.2.4 Compressed Vertex Coordinate Array . 193
10.2.5 Compressed Vertex Normal Array . 194
10.2.6 Compressed Vertex Texture Coordinate Array . 197
10.2.7 Compressed Vertex Colour Array . 198
10.2.8 Compressed Vertex Flag Array . 201
10.2.9 Point Quantizer Data . 201
10.2.10 Texture Quantizer Data . 202
10.2.11 Colour Quantizer Data . 202
10.2.12 Uniform Quantizer Data . 204
10.2.13 Compressed Entity List for Non-Trivial Knot Vector . 204
10.2.14 Compressed Control Point Weights Data . 208
10.2.15 Compressed Curve Data . 209
10.2.16 Compressed CAD Tag Data . 212
10.3 Encoding Algorithms . 215
10.3.1 Uniform Data Quantization . 215
10.3.2 Bitlength CODEC . 216
10.3.3 Arithmetic CODEC . 217
10.3.4 Deering Normal CODEC . 222
10.4 zlib compression . 224
11 Common Data Conventions and Constructs. 225
11.1 General Data Conventions and Constructs .
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