3D CAD Glossary J - Z

LAN
An acronym for Local Area Network. One of several systems used to link computers together in order to share data, programs, or peripherals.

Layer
A logical separation of data to be viewed individually or in
combination. Similar in concept to transparent acetate overlays. Today's 3D modeling systems use a standard of 256 numbered layers (0-255) and many systems also support an unlimited number of user defined named layers.

Linetype
Sometimes referred to as line font. It represents the appearance of a line. For example, a continuous line has a different linetype than a dashed line. Many 3D modeling applications allow you to define the characteristics of a linetype such as the length of segments and spaces within the repeating pattern of the linetype.

LMB
An acronym for Left Mouse Button.

Middle Mouse Wheel
Many of today's mouse type input devices have more than the traditional two buttons that were incorporated into their original designs. A three button mouse is common. Also common is a middle mouse wheel where the middle button is also a wheel used as a scrolling device in Windows® based applications. The wheel also serves as the middle mouse button when pressed.

MMB
An acronym for Middle Mouse Button.

NIST
Acronym for National Institute of Standards and Technology. Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Commerce Department's Technology Administration. NIST's mission is to develop and promote measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life.

Part Classification
Mechanism to classify parts and other elements of a product by their function or by the processes used to manufacture them.

PDES
See IPO.

PDM
An acronym for Product Data Management. PDM is a technology for managing all engineering and manufacturing data for a product and to control the product development cycle.

Rectangular Coordinate System
(See Coordinate System)

Reference Planes
(See Datums)

RMB
An acronym for Right Mouse Button.

SGML
Acronym for Standard Generalized Markup Language. SGML (ISO 8879) defines a method (a set of rules) and a "language" for document representation. SGML provides a formal markup procedure used to "tag" or identify elements in the document text, is machine processable, and is independent of system and output environments. SGML notation can be "parsed" (checked for valid syntax and structural conformance).

SGML provides a coherent and unambiguous grammar and syntax ("language") for describing both document content and "structure" - regardless of: the type of document or the nature of the document's text. See also ISO.

Solid
A B-Rep (Boundary Representation) data structure containing topological information that defines a closed 3D space. The boundary of a solid separates points inside from points outside the solid. In today's hybrid 3D CAD systems, solid models can be temporarily "open" volumes while still applying solid features.

STEP
An acronym for Standard for the Exchange of Product Data. STEP is a universal neutral data format for product data. Currently being developed with the participation of dozens of the world's leading manufacturers, STEP enables all people contributing to the design, manufacturing, marketing, and supply of a product and its components to contribute to, access and share its information. See also IGES, IPO and ISO

Top-Down Assembly Design
(See Assembly Modeling)

VRML
Acronym for Virtual Reality Modeling Language. VRML (ISO/IEC 14772) is a file format for describing interactive 3D objects and worlds. VRML is designed to be used on the Internet, Intranet, and local client systems. VRML is also intended to be a universal interchange format for integrated 3D graphics and multimedia.

VRML may be used in a variety of application areas such as engineering and scientific visualization, multimedia presentations, entertainment and educational titles, web pages, and shared virtual worlds. See also ISO.