The document discusses the need for standardization in graphics for mechanical engineering, emphasizing the importance of interface standards like GKS, PHIGS, IGES, STEP, and DXF for hardware compatibility and software interoperability. It outlines the functions and structure of key graphics standards, including the detailed sections of IGES and the application of STEP in the engineering lifecycle. Additionally, the document describes the Drawing Exchange Format (DXF) developed by Autodesk, detailing its components and structure for data exchange in CAD applications.

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CHAPTER 4: GRAPHICS STANDARD
Prof. RATNADEEPSINH M. JADEJA
Assistant Professor
Mechanical Department

2. Mechanical Engineering Department – School Of Engineering
STANDARDIZATION IN GRAPHICS
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NEED OF STANDARDIZATION
• Exchange of hardware
• Adjusting new hardware from different vendors
So proper interface standards are required to be established, some of them are
• GKS (Graphics Kernal System)
• PHIGS (Programmer’s Hierarchical Interface for Graphics)
• GKS-3D
• IGES
• STEP
• DXF

3. Mechanical Engineering Department – School Of Engineering
STANDARDIZATION IN GRAPHICS
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GRAPHICS DATABASE
APPLICATION PROGRAMS
GRAPHICAL FUNCTIONS
DEVICE DRIVER
DEVICE
DEVICE DRIVER
DEVICE
DXF, IGES, STEP, SET
GKS, PHIGS, CORE
VDI, VDM, NAPLPS

4. Mechanical Engineering Department – School Of Engineering
GRAPHICS KERNEL SYSTEM (GKS)
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• Difficulties in running a program in different system
• Major portion of program is almost common for all same kind of programs
• A number of attempts are made to provide a set of useful procedures or routines for
graphical manipulation, but with specific objective or hardware in mind.
The main objective for GKS is…..
1. To provide the complete range of graphical facilities in 2D, including the interactive
capabilities.
2. To control all types of graphic devices such as plotters and display devices in a
consistent manner.
3. To be small enough for a variety of programs.

5. Mechanical Engineering Department – School Of Engineering
Application Program
Application Oriented layer
Language Independent Layer
GRAPHICS KERNEL SYSTEM (GKS)
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Other Resources Graphical Resources
Operating system
Graphics Kernel System
Layer Model of Graphics Kernel System

6. Mechanical Engineering Department – School Of Engineering
INITIAL GRAPHICS EXCHANGE SPECIFICATION (IGES)
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THE IGES FILES CONSISTS OF THE FOLLOWING 6 SUB-SECTIONS
1. FLAG SECTION(Fundamental Information)
2. START – S (Man readable information)
3. GLOBAL – G (product, name of company, date, system detail, drafting standards)
4. DIRECTORY – D (Index of file and attribute information)
5. PARAMETER – P (Data associated with the entities)
6. TERMINATE – T (sub total of the records)

7. Mechanical Engineering Department – School Of Engineering
STANDARD FOR THE EXCHANGE OF PRODUCT MODEL DATA (STEP)
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This is a copyright of ISO, and is not freely available..
Data across the full engineering and manufacturing life cycle.
Can be used for CAD, CAM, CAE and PDM
The broad scope of STEP is as below
1. The standard method for completely defining a product through its life.
2. Exchanging data electronically.

8. Mechanical Engineering Department – School Of Engineering
DATA EXCHANGE TRANSLATORS
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System
1
System
2
System
3
System
4
System
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System
1
System
2
System
3
System
4
System
5
Neutral
Database
Structure
Translator 1-2 Translator 1-3
Direct Translators Indirect Translators

9. Mechanical Engineering Department – School Of Engineering
DRAWING EXCHANGE FORMAT (DXF)
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• Developed by Autodesk to use with AutoCAD.
• The file is ASCII text file or special binary form files.
• Different sections are as follows
1. Header section
• General information about drawing (like AutoCAD version no., number of
system variable and respective values)
2. Classes section
• Application defined classes and is permanently fixed in class hierarchy.
3. Table Section
• Line type table,
• Layer table
• Text style table etc..
4. Block section (Information about block)
5. Entity section (Information about graphical entities.)
6. Object section
• Contain non graphical objects in drawing. (e.g. Multiline)