graphical interfacing standards used in cad cam for communication of cad cam softwares.

1. Graphical interfacing standards
In CAM/CAD by VAIBHAV TAILOR

2. introduction
 Many companies use different CAD systems internally and exchange CAD data with
suppliers, customers and subcontractors. Transfer of data is necessary so that, for
example, one organization can be developing a CAD model, while another
performs analysis work on the same model; at the same time a third organization is
responsible for manufacturing the product. The CAD systems currently available in
the market differ not only in their application aims, user interfaces and
performance levels, but also in data structures and data formats therefore accuracy
in the data exchange process is of paramount importance and robust exchange
mechanisms are needed.

4. EXCHANGE OF MODELLING DATA

5. Standardization in graphics
Following are some of the interface standards at various levels;
 GKS (Graphical Kernel System)
 PHIGS (Programmer’s Hierarchical Interface for Graphics System)
 IGES (Initial Graphics Exchange Specification)
 DXF (Drawing Exchange Format)

6. VARIOUS STANDARDS IN GRAPHICS
PROGRAMMING

7. Graphical Kernel System (GKS)
 It is desirable to have programs interchangeable with a number of systems, and
also to make programmers learn the system once and then repeatedly use it on
different systems.
 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.

8. PHIGS (Programmer’s Hierarchical Interface
for Graphics System)
 PHIGS (Programmer's Hierarchical Interactive Graphics System) is an standard
for rendering 3D computer graphics, considered to be the 3D graphics standard for
the 1980s through the early 1990s. Subsequently, a combination of features and
power led to the rise of OpenGL, which became the most popular professional 3D
API of the mid to late 1990s.
 The word "hierarchical" in the name refers to a notable feature of PHIGS: unlike
most graphics systems, PHIGS included a scene graph system as a part of the basic
standard. Models were built up in a Centralized Structure Store (CSS), a database
containing a "world" including both the drawing primitives and
their attributes (color, line style, etc.)

9. IGES (Initial Graphics Exchange
Specification)
 The IGES is the most comprehensive standard and is designed to transmit the
entire product definition including that of manufacturing and any other associated
information.
 Using IGES, a CAD user can exchange product data models in the form of circuit
diagrams, wireframe, freeform surface or solid modeling representations.
Applications supported by IGES include traditional engineering drawings, models
for analysis, and other manufacturing functions.

10. DXF (Drawing Exchange Format)
 The DXF format has been developed and supported by Autodesk for use with the
AutoCAD drawing files.
 DXF was originally introduced in December 1982 as part of AutoCAD 1.0, and was
intended to provide an exact representation of the data in the AutoCAD native file
format, DWG (Drawing), for which Autodesk for many years did not publish
specifications. Because of this, correct imports of DXF files have been difficult.