jt using the file format specification 8 · 2016-05-26 · jt | ra | folie 8 jt segment types...

SEPTEMBER 12 -14 2010 International Conference

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JT Using the File Format Specification 8.1

Jochen Rassler

Technische Universität Darmstadt

JT | Ra | Folie 2

Physical and schematic JT File

25.08.2010 | Using JT Specification

Tessellation

Exact BREP

Attributes

PMI

JT

Siemens

JT | Ra | Folie 3

JT File Content


Siemens

File Header

TOC Segment

Data Segment

Melanie Stiller, Hochschule der Medien 4

Basics - A journey to Theoretical Computer Science

The JT-Format is treated as a formal language

Language

Semantic Grammar

Format

Semantic Syntax

Text

Sentence („JT is leightweight.“)

Word („leightweight“,…)

Alphabet ∑ = {a-z, A-Z}

JT-File

Element (B-Rep, MetaData,..)

Data Typ (float, int, String,…)

Alphabet ∑ = {1,0}


The syntax

Text = sentence

Text

Text = sentence„ Nice to meet you.

My name is Melanie.

I evaluated the JT specification.“

„My name is Melanie.

I evaluated the JT specification.

Nice to meet you. “Example:

Counter example:

„evaluated the JT spezification I“- definition of the grammar is not clear!

- syntax is wrong

- semantic not easily understandable

sentence = word sentence | ε

ε = empty word


The syntax

Text = sentence

Text

Text = sentence„ Nice to meet you.

My name is Melanie.

I evaluated the JT specification.“

„My name is Melanie.

I evaluated the JT specification.

Nice to meet you. “Example:

sentence = subj verb obj

subj = „I“| „You“| „It“| …

…

„ I evaluated the JT specification.“

Correct:

JT | Ra | Folie 7

JT File Header and TOC Segment


I32 : EntryCount

TOCEntry

UChar : Version

UChar :

ByteOrder

I32 :

FileAttributes

I32 : TOCOffset

GUID :

LSDSegmentID

80

File Header TOC Segment

JT | Ra | Folie 8

JT Segment Types


Type Data Contents

ZLIB Compression Conditionally

Applied to all of the Segment's

Element Data1 Logical Scene Graph Yes

2 JT B-Rep Yes

3 PMI Data Yes

4 Meta Data Yes

6 Shape No

7 Shape LOD0 No

8 Shape LOD1 No

9 Shape LOD2 No

10 Shape LOD3 No

11 Shape LOD4 No

12 Shape LOD5 No

13 Shape LOD6 No

14 Shape LOD7 No

15 Shape LOD8 No

16 Shape LOD9 No

17 XT B-Rep Yes

18 Wireframe Representation Yes

JT | Ra | Folie 9

Scenegraph & Occlusion Culling


SGI

JT | Ra | Folie 10

JT Brep Data


Geometry

Solid

Surface

Line

Point

Topology

Shell

Face

Body

Loop

Edge

Vertex

Tags

Tags

Com

pre

ssed a

n L

ate

Loaded

JT | Ra | Folie 11

PMI


JT | Ra | Folie 1225.08.2010 | Using JT Specification

Thank you for your interest!

We are open to questions:

JT Spec contents: Jochen Rassler

Problems using JT Spec: Dick Dietz

jt using the file format specification 8 · 2016-05-26 · jt | ra | folie 8 jt segment types...

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