graphics standards

Arvind Deshpande

Incompatibility among representations

Complex CAD/CAM systems

Shape, non-shape, design and manufacturing data

Need to integrate and automate design and manufacturing processes to obtain maximum benefits from CAD/CAM systems

Direct translators and neutral formats

4/10/2012 2Arvind Deshpande(VJTI)

GKS (Graphical Kernel System)

PHIGS (Programmer's Hierarchical Interface for Graphics)

CORE (ACM-SIGGRAPH)

GKS-3D

IGES (Initial Graphics Exchange Specification)

DXF (Drawing Exchange Format)

STEP (Standard for the Exchange of Product Model Data)

DMIS (Dimensional Measurement Interface Specification)

VDI (Virtual Device Interface)

VDM (Virtual Device Metafile)

GKSM (GKS Metafile)

NAPLPS (North American Presentation Level Protocol Syntax)


The main objectives that were put forward for

GKS are:– To provide the complete range of graphical

facilities in 2D, including the interactive

capabilities,

– To control all types of graphic devices such as

plotters and display devices in a consistent

manner,

– To be small enough for a variety of programs


GKS 3D

PHIGS

NAPLPS


IGES is the most comprehensive standard and is designed to transmit the entire product definition including that of manufacturing and any other associated information


1. Flag section – Optional ASCII/binary/compressed ASCII

2. Start section(S) – Man readable prologue

3. Global section(G) – Details of product, person originating the product, name of the company originating it, date, details of system which generated it, drafting standard used etc.

4. Directory section(D) – Index for the file and attribute information like colour, line type etc.

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5. Parameter Entry section(P)

Geometric entities- Point, line, arc, different surfaces, curves, solid primitives etc.

Annotation entities – Angular dimension, diameter dimension, label, note, etc.

Structure entities – Associativity definition, text font definition, color definition, units data etc.

6. Terminate section – Sub-totals of record in each of earlier sections


The broad scope of STEP is as follows:

– The standard method of representing the

information necessary to completely define

a product throughout its entire life, i.e.,

from the product conception to the end of

useful life.

– Standard methods for exchanging the data

electronically between two different

systems.


The DXF format has been developed

and supported by Autodesk for use with

the AutoCAD drawing files.


A coordinate measuring machine is a dimensional measuring device, designed to move the measuring probe to determine the coordinates along the surface of the work piece. Apart from dimensional measurement, these machines are also used for profile measurement, angularity, digitizing or imaging.

A CMM consists of four main components: the machine, measuring probe, control system and the measuring software. The control system in a CMM performs the function of a live interaction between various machine drives, displacement transducers, probing systems and the peripheral devices.


Control systems can be classified according to the following groups of CMMs.1. Manually driven CMMs2. Motorized CMMs with automatic probing systems3. Direct computer controlled (DCC) CMMs4. CMMs linked with CAD, CAM and FMS etc.

The first two methods are very common and selfexplanatory. In the case of DCC CMMs, thecomputer control is responsible for themovement of the slides, readout fromdisplacement transducers and datacommunication.



Cantilever type CMM

Gantry type CMM

Dimensional Measurement Interface

Specification (DMIS) is a new standard

in communication being established by

CAM-I for manufacturing.


Function:Specifies a circularity tolerance for a

feature, and assigns to it a label.

• Format: T(label) = TOL/CIRLTY, tolzon,

var_1, F(label)

• var_1 can be: MMC or: LMC or: RFS

• label is an alphanumeric label assigned

to the tolerance, and is up to 10 characters

in length.


graphics standards

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