2D – Visual representations created with width and height. Photos, photosimulations, CAD plans and sections, and video are all 2D.

3D -- Visual representations created with width, height, and depth. 3D modeling can create a realistic tour of an item or area.

3D CAD System -- A 3D CAD (Computer Aided Design) system provides a tool that enables the complete geometric definition of objects, and far exceeds the possibilities of the traditional drawing board, protractor and pen. It is therefore not surprising to hear that the use of an advanced CAD system that enable the efficient transition from 2 dimensional (2D) to 3D construction greatly improve the construction process, both in quality and in time-to-market. The use of CAD systems may also result in reduced construction errors, higher levels of production quality and improved manufacture. 3D CAD systems also enable the use of generated data in subsequent processes during the product development cycle (volume, weight, inertial analysis, functional and manufacturing simulation, visualization).

4D – 4D refers to visual representations created in 3D (width, height, and depth) but that also include the element of time passing.

Absolute -- The relative setting that places a graphic cell on the same level on which it was created.

Accept -- To click the Data button to approve the placement of a data point at the location of a tentative point or to confirm the identification of an element that is highlighted.

AccuDraw -- Drafting aid used to apply precision to geometry without affecting the flow of drafting or sacrificing the interactivity afforded by dynamic update.

AccuSnap -- A snapping mode that may be used by itself, or in combination with AccuDraw, to reduce the number of button presses required during a design session. AccuSnap provides graphical assistance — a smart pointer — for snapping to elements.

Acrobat – A product from Adobe Systems, Inc. which converts text documents, word for word, image for image, into fully --searchable electronic documents. The electronic document, with the exact look and feel of the original but with added hyperlinks, is stored in PDF (Portable Document Format). The PDF document can be viewed and printed with the free Adobe Acrobat Reader. The conversion process involves printing, from any word processor or application package, to an Adobe PDF Writer printer driver, rather than printing to a physical printer. The driver stops and asks where you wish to store the PDF document. Links, table of contents and other easy-to-create features are done with Adobe's Acrobat Exchange. The latest revision of Acrobat’s PDF format- version 7, includes the ability to incorporate 3D models with animation or interactivity attached. The 3D format built into the PDF format is based on the U3D (Universal 3D) format.

ACS -- (Auxiliary coordinate stytem.) A coordinate system with user-specified origin and orientation that can be defined, activated, saved, and recalled during a design session.

ACS plane lock -- A setting that, when turned on, forces each data point to lie on the XY-plane of the active auxiliary coordinate system, setting all Z-coordinates to zero. This concept applies only to 3D files.

ACS plane snap lock -- A setting that, when turned on, causes MicroStation to try to find a point on the XY-plane of the active auxiliary coordinate system to snap to when a tentative point is entered. This lock applies only to 3D files.

ACS triad -- At the time an auxiliary coordinate system is defined, MicroStation displays this three-arrow representation (in 3D) to indicate the X- and Y-axes and origin.

Action string -- Defines the action MicroStation performs when a tool is selected or a menu item is chosen.

Active angle -- The angle, in degrees, used with cell placement and text placement tools that require an angle specification.

Active attributes -- The setting that determines the color, line style, and line weight of an element upon placement.

Active cell -- The cell that is placed with the cell placement tools.

Active class -- The class (primary or construction) of an element upon placement. DGN files are normally composed of primary elements. Construction elements are usually placed to help place primary elements and are usually not plotted.

Active color -- The setting that determines the color of an element upon placement.

Active color table -- The set of up to 256 colors from which the active color can be selected. The active color table is modified, attached, and saved in the Color Table dialog box.

Active command -- The command that has most recently been activated from a tool box, menu, or key-in.

Active control indicator -- The dotted rectangle that indicates the input focus in dialog boxes.

Active depth -- The depth within the view cube of the plane upon which data points are entered. The plane is perpendicular to the Z-axis of the view. There is an active depth associated with each view.

Active DGN file -- The DGN file currently opened for viewing and/or manipulation.

Active entity -- The row in the database table that is linked to a graphic element when a database attachment is executed.

Active font -- The setting that determines the font of a text element upon placement.

Active level -- The setting that determines the level upon which an element is placed.

Active line style -- The setting that determines the line style of an element upon placement.

Active line weight -- The setting that determines the line weight of an element upon placement.

Active pattern angle(s) -- The setting that determines the angle at which the active pattern cell is placed by Pattern Area, the angle of the lines placed using Hatch Area, or two settings that determine the angles of the lines placed using Crosshatch Area.

Active pattern cell -- The setting that determines the cell that is used for patterning.

Active pattern scale -- The setting that determines the scale at which the active pattern cell is placed during area patterning and linear patterning.

Active pattern spacing -- The distance(s) between adjacent pattern cells placed using Pattern Area. The distance(s) between lines placed using Hatch Area or Crosshatch Area.

Active point -- The setting that determines whether a cell, symbol, or zero-length line is drawn by the point placement tools.

Active scale factor(s) -- The setting that determines the amount of scaling applied to a cell when placed, to selected elements, or to the fence contents when using Scale. The scale factors in the X-, Y-, or Z-direction can be identical or each can be different.

Active text height -- The setting that determines the height of text upon placement.

Active text width -- The setting that determines the width of text upon placement.

AEC dimension format -- Dimensions that conform to architectural, engineering, and construction conventions.

Algorithm -- A computational method for solving problems. Much like a recipe in cooking, or a plan of attack in the military. Developing the algorithm in machining is the pre-planning process that creates the orderly procedure for machining processes to occur.

Align view -- To make one view display the same area (in 2D) or the same volume (in 3D) as another view.

Alphanumeric -- A string of characters that takes the form of letters, numbers, and some symbols (e.g. @, $, and punctuation).

Alternate key-in -- A short cut way to enter a key-in command. For example, AA= is an alternate key-in for ACTIVE ANGLE. Ambient Light – light that exists randomly in an environment. Ambient light creates overall scene brightness, but not shadow.

Animation -- A sequence of images that can be displayed in rapid order to create the effect of motion. Animations can be 2D or 3D.

Application software -- Software that allows you to more efficiently perform specific tasks with MicroStation. These applications include: MDL applications, key-in scripts, and macros.

APT Programming -- Automatically Programmed Tools. A universal computer assisted programming system for multi-axis contouring programming.

Arc -- A regularly curved open element that has a constant radius around a single center point.

Architectural Desktop (ADT) -- Autodesk Architectural Desktop -- architectural and civil engineering application by Autodesk, based on AutoCAD kernel and AEC objects.

Area attribute -- Whether an area is a solid or a hole.

Area filling -- See fill.

Area patterning -- Placement of the active pattern cell (at the active pattern angle, scale, and spacing) in an area bounded by a shape, ellipse, circle, fence, or complex shape. The cell is repeated in a rectangular array spacing as many times as necessary to fill the area.

ARX (Autocad Runtime eXtension) -- compiled AutoCAD add-on application file (most often programmed in C++)

ASCII (American Standard Code for Information Exchange) -- A data transmission code that has been established as an American Standard by the American Standards Association.

Aspect ratio --height/width proportions of graphics. Some programs allow you to maintain the aspect ratio when sizing a picture, i.e. when you change the width, the height changes proportionally so that the resulting image does not look distorted.

Associated dimensions -- Dimensions that update automatically as the element they dimension is modified.

Association lock -- The setting that, when turned on, causes element associations to be created when an element is snapped to while using Place Multi-line, a dimensioning tool, or a cell placement tool (with Use Shared Cells on).

Association point -- A point created by snapping while using Place Multi-line, a dimensioning tool, or a cell placement tool (with Use Shared Cells on) when Association Lock is turned on. An association point does not have its own coordinates, but is positioned by the coordinates of the point it is associated with.

Attach -- To activate a (paper, cursor button, or sidebar) menu. To define (a cell library, color table, or reference) for use with a DGN file.

Attributes -- Line color, line style, line weight, and fill color (for closed elements).

Authoring software -- programs used to create full, multimedia productions, such as simulations and tutorials. Although most of these programs have some point --and --click features to simplify development, most require some knowledge of programming language concepts. Popular authoring software packages include Asymetrix ToolBook, Microsoft Visual Basic, Macromedia Director and Authorware. At the "lower" end, presentation software, like Microsoft PowerPoint, provide simpler ways to put multimedia into presentations. Typical authoring systems: Macromedia Authorware and Macromedia Director (Mac & Windows), Asymetrix's Multimedia Toolbook/Assistant/Librarian (Windows), HyperStudio (Mac & Windows), Microsoft Visual Basic (Windows).

AutoCAD -- a general 2D/3D CAD application by Autodesk; world's most used CAD program; platform for add-on application

Auxiliary coordinate system (ACS) -- A coordinate system with user-specified origin and orientation that can be defined, activated, saved, and recalled during a design session.

AVI (Audio Video Interleaved) -- Windows format for saving video with sound.

Axis increment -- The setting that determines, in conjunction with axis start angle, the possible axes for data points when Axis Lock is on. For example, if axis increment is 45 degrees and axis start angle is 0 degrees, the possible axes are 0, 45, 90, 135, 180, 225, 270, and 315 degrees.

Axis lock -- The lock that forces data points to be placed at axes that are at specific angles from the most recent data point or tentative point, constraining the movement of elements or placement to multiples of the Axis Increment from the Axis Start Angle.

Axis of revolution -- The axis about which an object is revolved by the commands that create surfaces and volumes of revolution. This concept is used in 3D designs.

Axis start angle -- The setting that determines (in conjunction with axis increment) the possible axes for data points when Axis Lock is on. For example, if axis increment is 60 degrees and axis start angle is 30 degrees, the possible axes are 30, 90, 150, 210, 270, and 330 degrees.

Balanced colors -- A representative spread of colors evenly spaced across the color spectrum.

Batch processing -- Technique in which items to be processed must be coded and collected into groups prior to processing.

Bézier curve -- A B-spline curve with the same number of poles as its Order.

Bitmap -- Pixel oriented (raster) data. Bitmaps are created by capturing an image on the screen (hardware) or can be generated by an algorithm (software).

Block -- A single line of NC code is a block, a block represents sufficient information to a CNC machine to perform a single line or arc movement.

Block Delete -- A function that permits selected blocks of code to be ignored by the control system, at the operators discretion.

Boreline -- When a 3D tentative point is entered in a particular view, a reference line perpendicular to the plane of that view is created. The boreline sets the coordinates of the plane in which it is defined for snapping in other views. Thus, in views where the boreline appears as a line, a data point snaps to a location on the boreline, ignoring the active depth.

Boresite lock -- A setting that, when turned on, allows location of any element that lies near a boreline at the position of the pointer. With Boresite Lock turned off, only elements near the active depth can be located. This concept applies only to 3D files.

Browser -- A program that lets you view Web documents.

B-spline curve -- A free-form, parametrically defined curve in which each pole (vertex) has an influence over a defined range of the curve.

B-spline surface -- A free-form, parametrically defined surface in which each pole (vertex) has an influence over a defined range of the surface.

Buffer storage -- A place in which information in a control system or computer is stored for use at a later time.

Bug --A programmed error or oversight, a glitch.

Buttons -- Areas in dialog boxes that you click to start, save, or dismiss an operation.

C++ -- Compiled object-oriented programming language based on the C-language.

CAD -- A Computer Aided Design (CAD) package enables the planning, design and construction of objects. The term is used by different Hardware and software manufacturers to refer to varying concept involved in the digital generation and evaluation of objects. CAD Systems represent objects in two or three dimensions and allow for these objects to be viewed from any angle, and to be edited if needed. CAD systems may pursue entirely different goals; they may be geared toward the pure drawing or just the construction of objects. Other systems may include both these aspects and provide additional features like analysis or evaluation tools.

CAE -- Computer Aided Engineering refers to the construction and analysis of objects using virtual methods. Usually, CAE includes activities of design, planning, construction, analysis and production planning and preparation (CAP), though these are not necessarily all included. Some CAE packages may include only specialized subset of the above features.

CAI -- computer-assisted instruction.

CALS -- The United States Department of Defense Computer-aided Acquisition and Logistic Support initiative, which was created to integrate and standardize all digital data received from Department of Defense suppliers. MicroStation supports CALS compliance by providing corresponding settings files.

CAM -- (Computer Aided Manufacturing) -- The use of computers to assist in manufacturing.

Camera -- Like the function of an actual camera, the camera in MicroStation defines the portion of the design that is displayed when using perspective projection. The camera can be positioned and oriented in any manner required. Various lenses are available to modify the resulting image.

Camera position -- When using the view camera, the position from which the model is viewed.

Camera settings -- When using the view camera, the settings you adjust to control projection.

Camera view -- Any view in which the camera is on (perspective projection is active).

Canned cycle -- A preset sequence of events initiated by a single command.

Capture, video -- Video capture cards let you record/digitize pictures for use with a computer. The pictures may be still-images or movies. Once captured, the picture data is compressed using a CODEC, with playback requiring CODEC --decompression. Intel's Smart Video Recorder board, an excellent capture card, can compress video real-time, or "on the fly", provided you have a fast machine and lots (and lots) of defragmented storage.

Cartesian coordinates -- A three dimensional system whereby the position of a point can be defined with reference to a set of axes at right angles to each other.

Cascade -- The arrangement of stacked views of windows or views in numerical order, with the lowest numbered view entirely visible and the title bars of all other views visible.

Cascading Style Sheets/CSS -- Cascading Style Sheets (CSS) is a mechanism for allowing web authors and readers to attach styles including fonts, colors, etc. to HTML documents.

Cavity wall -- An architectural term for a wall that is not solid.

C-Axis --The axis of circular motion of a machine tool member or slide about the Z-axis. C-axis values are degrees of rotation about the Z-axis.

CBT -- Computer-based training. Used synonymously with computer-assisted training (CAI).

CD-R (Recordable CD-ROM, CD-Recordable) -- Software/hardware needed to create your own CD's -- for backup/archive, catalogs and other large documents, and multimedia.

CD-ROM -- Compact Disc Read-Only Memory. From single-session, single-speed units, CD-ROM drives are now multi-sessioned, and read information 2X, 4X, 6X, 8X and 10X times as fast as original music CD players. Computer CD-ROM drives can slow down to single-speed to play music CD's: In a pinch, you can play music CD's with Windows' Media Player (Use the Control Panel to add the needed driver), although typically you would use the software that comes with the CD-ROM drive.

CD-ROM "hybrids" -- CD-ROM's with embedded Internet links. Although the Web can provide current information, i.e. timely updates and corrections, it lacks the bandwidth to deliver large multimedia files quickly. The "Internet-enabled" CD-ROM, or "cybrid," is being touted as a software solution that will use the strengths of both technologies. The parts of a program that can slow down access time if downloaded from the Internet (multimedia, index searches) are kept on the CD-ROM for faster loading. The Internet side of the equation is used for providing, and for adding new features without the need to send out a new CD-ROM disc. In the near future, look for hybrid DVD's.

CD-RW (CD-ReWritable) -- an erasable CD-ROM, called CD-RW, or CD-ReWritable. CD-RW technology differs from CD-Recordable (CD-R) technology, which can be recorded on only once. If a mistake is made, the disc is worthless.

Cell -- A complex element composed of a group of primitive or other complex elements that is stored in a cell library for repeated placement.

Cell definition -- The graphical elements that make up a cell.

Cell library -- A file that is used to store cells. To access cells in a cell library, the library must be attached to the active DGN file, except if the Cell Selector dialog box is used.

Cell origin -- The point, specified during cell creation, about which the cell is placed (the origin corresponds to the data point when the cell is placed in the design).

CGI (Common Gateway Interface) -- server-side programs, running at the request of the client, that typically perform interactive Web actions. Normally, servers "serve" the content of static files (html, images, movies, sounds). In CGI, clients request a program to be executed and its results to be returned, as in database or search applications. All form-processing requires CGI.

CGM -- Computer Graphics Metafile, which is an ANSI standard for the exchange of picture data between different graphics software that is device- and environment-independent.

Chamfer -- To cut a line across two linear elements, connecting the elements and modifying either one or both of the original elements.

Check box -- A square box in a dialog or setting box that can be clicked to toggle the associated setting.

CIM -- Computer Integrated Manufacturing refers to the integrated use of computer aided techniques in manufacturing. This includes CAD, CAE, CAM , etc, but the term is interpreted in a variety of ways by various suppliers of CIM solutions. The main requirement of CIM is a central shared database that may be accessed by the different disciplines deployed during the manufacturing process, such as design, development, manufacture, distribution, billing etc. CIM is a superset of CAM .

Circular interpolation -- The process of generating up to 360 degrees of arc using only one block of information as defined by EIA.

Class -- An element attribute, usually primary or construction.

CLData -- Processor output that contains information regarding cutter location.

Click -- To press or tap once on a cursor or mouse button; to press a push button or check button in a dialog box.

Clip -- To divide an area, elements, or portions of elements in a design from the rest for manipulation or display.

Clip art -- collections of pictures/photographs. Many application programs, such as PowerPoint, contain built-in clipart.

Clip mask -- Used with the Raster Manager or Reference tools, a clip mask allows you lets you clip out a portion of the image. Masking can be used, for example, to clear an area for text display.

Clipping boundary -- A boundary (established with a fence or from a named view) that separates the part of a reference that is displayed from the part that is hidden.

Clipping plane -- A plane that defines the front or back of the view cube, the portion of a 3D design displayed in a view.

Closed -- Elements that completely enclose the area within their boundaries.

Closed B-Spline -- A complex curve that starts and ends at the same point, and encloses an area.

CNC -- Computerized Numerical Control.

CODEC – A program/device that COmpresses/DECompresses digital video. xxx Cinepak and Indeo (Intel) are examples of CODEC's. See CODEC Central for an in-depth look at CODEC's.

Coincident reference attachment -- A coincidentally attached reference has a one-to-one correspondence between its design plane and the design plane of the active DGN file. If the working units settings and global origin are identical in the two files, the coordinates in working units are identical as well.

Coincidentally -- Attaching a reference by aligning the coordinates of its design plane with those of the active DGN file, without any rotation, scaling, or offset.

Color fill -- An attribute that, when applied to a closed element, indicates the element's enclosed area as a solid shape of color.

Color Palette -- available color selections, ranging from 16 colors to 16.7 million. There are often color shifts from machine to machine that can have "unfortunate" results.

Color table -- In a DGN file, the color table determines the correspondence between the 256-color attribute values and display colors. It is displayed in a dialog box.

Column -- In a database table or file, a column or field represents the properties of objects (which are represented by records or rows.)

Command file -- A text file containing an SQL statement.

Command menu -- Paper mounted on the surface of a digitizing menu with blocks of varying sizes and shapes.

Compass -- A square or circle used to indicate the AccuDraw drawing plane origin, axes, and coordinate system. Color-coded hash marks indicate the positive X and Y axes.

Compile -- To generate a machine language program from a computer program written in a high level source code.

Complex chain -- An open complex element that is formed from a series of open elements, such as lines, line strings, and arcs.

Complex element -- An element created by combining several primitive elements.

Complex shape -- A closed complex element formed from a series of open primitive elements.

Components -- Groups of settings that comprise drawing settings group. Component types are: linear, text, cell, point, area pattern, hatching, dimension, and multi-line.

Compositing -- Combining two or more images to produce a new image. All or just some of each image might be used in the process.

Compression (file) -- Process for reducing file size, often called "zipping" or "archiving". The resulting, compressed file can be from a single, large file or can contain several files that have been squeezed into a single file. The many-to-one compression makes file group identification, copying, and transporting faster and easier.

Compression (video) -- Process which reduces the number of bytes required to store/transmit digital video. Typical schemes involve comparing frames and coding-out, or eliminating, inter-frame and intra-frame redundancies. The compression may be done by software, hardware or a combination of the two. On playback, the data is decompressed. See CODEC.

Compression, Lossless -- digitized video containing ALL the original video information.

Compression, Lossy -- digitized video which, to save space, does NOT contain all the original video information.

Cone -- An element composed of two circles on parallel planes with a surface connecting the two circles. A cone can be a solid (capped on both ends) or surface (not capped) element.

Configuration variables -- Equivalence strings that define where MicroStation is to look for certain files or classes of files. Configuration variables are tools for customizing your MicroStation working environment. For example, MicroStation knows to search for references in the directory (or semicolon-separated list of directories) specified in the configuration variable MS_RFDIR.

Constant shading -- A memory and time-efficient method of shading a rendered image by using only one color per polygon. The color of each polygon is calculated only once from the surface configuration and lighting source, producing a tiled effect in the final image.

Construction -- A type of element that is placed as a guideline from which to compose actual elements comprising a design.

Construction element -- See active class.

Control net -- A rectangular array of vertices that, together with the B-spline order, define the shape of a B-spline surface.

Control polygon -- A polygon whose vertices, together with the B-spline order, define the shape of a B-spline curve.

Control table -- A special table in each database to which linkages are established, also known as MSCATALOG.

Controls -- Parts of a dialog box such as text fields, check boxes, and option menus.

Cookie -- A "cookie" is a small piece of information, a virtual "sticky note", sent by a Web server to be stored, by your browser, on your hard drive. The cookie stores information about you and can be retrieved by the Website each time you visit there. Without them, sites would not be able to retain information about individual visits; thus, cookies store "state information." Cookies are passive files, typically used in .asp (Active Server Page) programming, and should not be confused with server-side databases that collect personal information you've voluntarily (or unwittingly) submitted. See Cookie Central.

Coordinate -- Location of a point in the design plane along the X (horizontal), Y (vertical), and Z (depth [3D only]) axes relative to the global origin.

Coordinate readout -- Format and precision with which coordinate, measurement, and angle data is displayed in the status bar and in settings and dialog boxes.

Cropping – Trimming, removing, or deleting part of an image, sometimes done to resize the image instead of scaling, and sometimes to focus on the more important elements of the image, cutting out background or other unneeded elements.

Crosshair -- The crosshair located on the digitizing tablet cursor is used as the positioning target to select a menu block from a paper menu. The crosshair pointer on the screen is used with element placement tools.

Crosshatch -- The process of constructing two sets of evenly spaced lines in a closed area bounded by a complex shape, closed element, or fence at the active pattern angles and spacing.

Cross-platform -- Files usable/executable with different operating systems. For example, Virtus WalkThrough, a 3 --D animator program, can produce "cross-compatible" animation files for Macintosh and DOS/Windows machines. "Power" Mac's let you change to the PC work-mode; "power" PC's can handle Macintosh software/files.

Cross-section -- A view of the interior of an object as it is sliced along a plane.

CSV file -- Comma-separated values file: The CSV file format is an interchange format for tabular data, such as the contents of a flat file database or a table in a relational database. In this text file format, the first line contains the database field (column) names separated by commas. Each successive line corresponds to a database record (row). On each such line, the subject record's field values are separated by commas.

CUI -- Custom User Interface -- XML file with menu definitions for AutoCAD (version 2006 and higher) replacing the MNU, MNS, MNC, MNR files.

Cursor -- Hand-held tablet cursor. Commonly called a “puck.”

Cursor button menu -- A set of actions assigned to buttons on a tablet cursor.

Cylinder -- A cone element in which the circles that define each end have the same radius.

Cylindrical ACS -- Auxiliary coordinate system in which positions are described by two magnitudes (R and Z) and an angle.

Data button -- The button on a mouse or digitizing tablet that is pressed to enter data points, identify elements for manipulation, accept a previous action, select tools, and operate dialog box controls.

Data point -- Input entered using the pointing device that designates a point in the design.

Database -- See relational database, non-graphical database.

Database attributes -- Information stored in a database manager and linked to a particular element in a DGN file.

Database interface -- Where associated data is stored in a separate relational database that is linked to elements in the DGN file.

Database linkage -- A relationship that allows data to be transferred between an element and a database table.

Database server -- A software program that handles database functions and runs in parallel with MicroStation.

Default font -- The font used to display a text element in the design when the font with which the element was placed is not found.

Degrees of freedom -- Freedom to vary placement of constraints from the model.

Delay unit -- A period of waiting time inserted into plotter output to accommodate output devices that cannot properly handle communications using baud rates of 9600 or higher.

Delete -- To remove an element(s) from the DGN file.

Derived cell -- A cell in a design that is derived from a dimension-driven cell.

Design composition -- A working collection of references used in the performance of particular engineering tasks. Design compositions are used by engineers and other technical professionals to communicate through the visual content of their designs.

Design cube -- The space in which elements are created in a 3D design.

Design geometry -- The construction geometry and the constraints that make up a complete design.

Design history -- The historical record of changes to the DGN file. Enables you to restore earlier revisions of a DGN file. When you create a revision, Design History captures the state of the DGN file at that moment.

Design model -- A model is a container for elements. Models can be either 2D or 3D, but they are most useful in their 3D form. It may be helpful to think of a DGN file as a stack of cards, with each card being a model. Every model has its own set of eight views. The model whose views are displayed or available for display at a given time is the active model.

Design plane -- The area in which elements are created in a 2D design.

Design session -- The period during which a DGN file is active.

Destination view -- A view that can be designated for attaching saved attributes and displays from a source view.

DGN file -- MicroStation document file that contains one or more models. These models may be design models or sheet models.

DGN workmode -- The default MicroStationworkmode in which the full functionality of the application is enabled.

Dialog box -- A window displayed on the screen that presents various controls that can be manipulated to set values that MicroStation will use.

DIESEL (Dumb Interpretively Evaluated String Expression Language) -- a simple macro language in AutoCAD and AutoCAD LT

Digital certificate -- DGN files can be protected by certificates. Users can be granted access to that certificate and all the rights to the file associated with certificate.

Digital Mockup -- A digital mockup primarily involves the virtual construction and assembly of objects. It is also a term used for software used to check for errors in the product construction during early phases in the development process. These analyses involve 3D CAD models and check for collisions, tolerances etc.

Digital rights -- The type of rights (i.e. view, edit , export, etc.) to a protected file assigned to a user.

Digital signatures -- The mechanism for indicating one's approval of DGN files to other users and communicating approval in a verifiable manner.

Digitizing -- The process of coding graphic information from paper sources (such as a map or other drawing) into a DGN file using a tablet.

Digitizing partition -- The area of a digitizing tablet in which the tablet cursor controls the screen pointer only within the part of the design in which features of the hard copy are being mapped. See partition, screen partition.

Digitizing tablet -- Pen-based input system, resembling a sketch pad. The pressure of the pen on the tablet is translated in electronic dot patterns. Many delivery companies, such as UPS, use tablet technology to record signatures upon package receipt.

Dimension -- A label in a design owing a linear, angular, or radial distance or angle measurement.

Dimension attributes -- The settings for all components of dimension elements, including text (color, weight, font, height, and width), lines (color, style, weight, and alternates), and level.

Dimension driven cell -- A cell that can be placed throughout a design and adjusts dynamically to reflect relationships defined at its creation.

Dimension element -- An element that contains all of the lines, arcs, terminators, and text in a dimension.

Dimension line -- The line component of a dimension that is usually parallel to and the same length as the object being dimensioned.

Dimension line terminators -- Symbols placed at the end of dimension lines that clarify the meaning of the dimensions.

Dimension mark -- Symbols placed with dimension text that clarify the meaning of the dimension text.

Dimensional constraints -- The constraints that define the exact dimensions of a construction.

DirectX -- 3D graphic programming API written by Microsoft. Allows programs to interface with and use built in high speed 3D graphic routines on graphic cards. Built into Windows 95 and 98.

Display cube -- In a 3D design, the volume of the design that appears in a view.

Display depth -- Collectively, the front and back of the view cube.

Display mode -- Determines whether the contents of a view are continuously rendered and, if so, the type of rendering.

Displayable attribute -- A tool that allows automatic text annotation of drawings. Attributes are stored in an underlying database, and are inserted into text nodes in the drawing which serve as placeholders.

Displayable attribute table -- Specifies the display format for each type of displayable attribute text node.

Displayable attribute text node -- You can place a copy of some or all of an element's database attributes as text in the DGN file in a displayable attribute text node. Selected attributes are loaded into the displayable attribute text node based on an SQL SELECT statement.

Distant light -- A type of light cell that casts light in a single direction.

Dithering -- The process of alternating two or more colors pixel by pixel across the screen to seemingly create a third color not available in the color palette.

DLL (Dynamic Link Library) -- a Windows' code module that is loaded and linked at runtime, then unloaded when it has finished executing.

DLP -- Digital Light Projectors. Contrast with LCD Projectors.

Dot pitch -- the distance between the pixels on the monitor. The smaller the distance, i.e. the denser the pixels, the clearer the picture resolution.

Double-click -- To press or tap twice in quick succession on a cursor button or mouse button, or to press on a list box item in a dialog box twice in quick succession.

DPI (dots per inch) – Print or display resolution expressed in number of points per one inch.

Drawing composition -- A method in which views of the model are attached to a sheet model as references. Sheet files with attached references can also be established independent of the design model file so that a wider range of individuals may access these files.

Drawing plane -- The plane on which data points are previewed with AccuDraw. In 3D, all data points will lie on this plane unless supplied by tentative point snap or by precision input key-in.

Drawing plane coordinate system -- The coordinate system (Rectangular or Polar) that defines the orientation of the drawing plane.

Drawing plane origin -- The origin of the drawing plane coordinate system. Drivers -- software, typically ending in .DRV in Windows systems, used to 'talk to' or manage hardware, like sound cards, printers, etc.

Drop complex element -- To return the primitive elements composing a complex element to their primitive element status.

Dropped frames -- In digital video, when the computer cannot keep pace with the displayed images, it drops frames in an attempt to catch up.

DSP (Digital Signal Processor) -- a special processor, additional to the CPU, that is dedicated to processing real-time audio and video signals. For example, the DSP chip on a sound card lets you add echoes, reverb and other special effects.

DWG files -- AutoCAD binary files that may be directly opened in MicroStation.

DWG workmode -- The MicroStationworkmode in which certain functionality is disabled by default in order to restrict MicroStation to creating only engineering data that can be stored in DWG format. DWG workmode is enabled by default when a DWG file is opened.

DXF -- A drawing exchange file format supported by most CAD packages. MicroStation reads and writes DXF files. A DXF file, when opened and subsequently modified in MicroStation is automatically saved as DXF.

Dynamic display -- A temporary representation, which moves when the pointer moves, that MicroStation displays until the placement is complete.

Dynamic update -- The display of elements being drawn or modifications being made, which moves as the pointer moves, before the element or modification is entered into the design.

Edges hidden line removal -- Creates a DGN file where the lines hidden by surfaces (in the view the edges file was generated from) are removed.

Element -- One of the entities that make up a DGN file. See graphic element.

Element attributes -- Color, line style, line weight, class, level, and fill. Other element attributes apply only to certain element types.

Element manipulation -- To delete, copy, move, rotate, mirror, or scale existing graphic elements in the design.

Element placement -- Tools used to place or construct graphic elements in the design.

Element symbology -- The color, line style, and line weight of an element.

Element tag -- Where associated data is stored in the DGN file with the graphical elements. Tags allow you to associate non-graphical data to elements in the DGN file if the data is relatively simple or if you must maintain compatibility with other CAD packages that store data inside their drawing files. The associated tag data may be copied from the tag, loaded into a database and linked back to the tag.

End Points -- The extremities of a span.

Enter data field -- One or more placeholders representing characters that reserve space in a text element for future input.

Enter data field special character -- The character used during text entry to designate a character position in an enter data field.

Entity -- The fundamental unit of data in a DWG, DXF, IGES, or CGM file. In general, entities are the equivalent of MicroStation elements.

Environment variable -- Named variables managed by the operating system and used to store string information and communicate between programs.

EPS (Encapsulated Postscript) – A graphics file format often used in desktop publishing packages, like PageMaker.

Express Tools -- Package of additional tools extending AutoCAD function set. A separate installation of this package is necessary.

Extension -- A suffix of characters optionally separated from the main part of a filename by a period (“.”) character. Traditionally, these have been used to designate the type of the file. For example, “.dgn” is commonly used to represent a DGN file.

Extension lines -- Component of dimensions that consists of lines extending from the dimensioned points to the dimension line.

Fast display -- A view attribute setting in which the display changes to an abbreviated form of the information which would normally be displayed. The nature of the information in the design does not change; only the presentation of it in the view changes. Fast display can be selected for cells, curves, text, and fonts.

Feature -- A part of a solids model created using feature modeling tools.

Feature control frames -- Indicators of geometric tolerancing in a design.

Feature modeling -- A technique for creating models with parametric-based solids using tools designed for this purpose.

Fence -- A polygonal boundary that designates multiple elements for simultaneous manipulation using fence tools.

Fence contents -- The elements and portions of elements operated on by fence tools determined by the fence selection mode. These elements can be enclosed by, outside of, or overlap the fence.

Fence filter -- A criterion (SQL SELECT statement) based on non-graphical data associated with elements that can be used to restrict the elements that are selected for fence operations.

Fence manipulation -- Tools that operate on the fence contents.

Fence selection mode -- A setting that determines the fence contents.

Field -- In a dialog box, an area into which a filename or other keyboard input can be entered. In a non-graphical database, a column.

File Transport Protocol (FTP) -- FTP is a method for retrieving files from a remote Internet site. Many sites out there allow what is termed an 'anonymous' connection. In other words, there exists a special username called 'anonymous' so that the site can act as a library of useful public domain programs and documents.

Filename -- Denotes the string used when calling for a generic file.

Filled -- Element that is colored within the planar element boundaries, as opposed to being displayed as just an outline.

Filled hidden line -- A rendering method that generates a surface model in which each visible surface is filled with the element color.

Fillet -- An arc constructed between and tangent to two converging lines.

Filter -- A filename pattern that limits filenames displayed in a list to those fitting the pattern. For example, “*.dgn.”

Firewire (IEEE-1394) -- serial interface technology that allows connection of devices at speeds up to 50 Mbytes/s. Used for devices such as video cameras so that they can feed real time video to a computer. Also allows devices to be hot-swapped (added and removed without rebooting). 

Fit -- A viewing operation that expands the area seen within a view to include all elements on all levels turned on in the view.

Fitted view -- View that shows all elements on the levels turned on in the view.

Flag -- A bitmapped image (raster element) with or without an associated explanatory message used for annotating a design with reminders or suggestions for future changes. Flash -- a product from Macromedia (as is Shockwave) that produces interactive vector-based animations called "Flash movies". Like Shockwave movies, Flash movies are intended for web-based distribution to web browsers.

Flashbulb -- A light source located at the camera position which illuminates any visible object.

Flat shading – A rendering technique where all points on a surface are given the same color. This allows for faster rendering, but reduced visual quality.

Floating -- A dialog box, tool box, or other part of MicroStation's graphical user interface that can be positioned freely on screen.

Fog -- A type of atmospheric cueing in which the shaded images are faded to the fog color as their distance from the eye increases.

Folding -- The process of attaching a view about an orthogonal axis of a line defined by two data points.

Font -- A style of lettering. Fonts are identified by both a number and a font name.

Font library -- A file that contains fonts for use by MicroStation or other applications. These fonts may include TTF and SHX formats.

FPS -- frames per second -- the number of picture images displayed per second, giving digital video the illusion of motion. Full --motion video, with no dropped frames, is considered 30 fps (NTSC standard).

Fractal – A class of geometric objects that are commonly used in the modeling of natural objects such as topography, plant life and clouds.

Frame -- A single picture in a computerized "movie"/digital video.

Frame grabber -- A video capture card that captures a single frame from a video stream and stores it as a still image.

Frame rate -- The number of images per second displayed in a stream of video. 30 fps (see above) is considered full-motion, television-quality video.

Freeform curves -- A freeform curve represent an object that may not be described analytically. The aim is to have the curve pass through a number of defined points with a maximum achievable smoothness. The resulting curves have continually changing tangent characteristics. Mathematically these curves require higher-order definition that may be differentiated in subsequent steps. Freeform curves may be defined as approximations (Coon or Bezier patches including NURBS patches) or as interpolations (Hermite and LaGrange patches). Combining a number of these patches enables the construction of arbitrary surfaces and curves.

Freeware -- The software author retains rights to the program, but allows users to copy and use the program without fee. The program thus cannot be resold or re-labeled without the consent of the originator.

Full-motion video -- digital video running at 30 fps (NTSC-US standard). It does not necessarily fill the screen.

Function key menu -- A way to assign actions to the function keys on the keyboard.

Function keys -- Application keys that are programmable; located at the top of the keyboard.

Geometric tolerancing -- Specification of how much a manufactured object can deviate from the geometry shown in a design.

Geometry -- Type of entity that defines physical shapes, including points, curves, surfaces, solids, and relations (collections of similarly structured entities).

Georeference -- A relationship between the coordinates of an image (map) and the real-word geographic coordinates.

GeoTIFF -- A specifc type of TIFF image with Georeference information encoded into the file header.

GIF (Graphic Interchange Format) -- a graphics file format originated by Compuserve, usable for Web pages. Use PaintShop Pro to convert other graphics file formats to .GIF format. Animated gifs provide a method for adding animation to web pages.

Global origin -- Location of the origin of the Cartesian coordinate system in design plane coordinates. When design plane positions are specified or reported in working units, they are relative to the global origin.

Gouraud shading – Rendering technique used commonly where the surface color is determined based on the colors of the surface vertices. This method creates smooth color gradiations over a surface.

Graphic -- A type of cell in which the symbology (color, line style, and line weight) is determined when it is created.

Graphic element -- A graphic component of the design. Referred to in user documentation as simply an “element.”

Graphic group -- A permanent grouping of elements (primitive or complex). An element can be a member of only one graphic group at a time.

Graphic group lock -- The setting that, when on, causes all elements in a graphic group to be manipulated whenever one member of the graphic group is manipulated. For example, if an element in a graphic group is deleted with Graphic Group Lock on, all elements in the graphic group are likewise deleted.

Graphical User Interface (GUI) -- A computer interface using point --and --click mouse actions (rather than the keyboard exclusively) and pictures (rather than text exclusively). Windows, Macintosh, Netscape and Mosaic are examples of GUI products.

Graphics accelerator -- a graphics card, used in animation production/creation, that speeds the display/preview of 3D animation.

Graphics tablet -- see digitizing tablet.

Grid -- A matrix of grid points (dots) and grid references (crosses) at user-defined intervals, used as a visual aid or in conjunction with the Grid Lock setting for precision input.

Grid lock -- The setting that, when on, forces all graphically entered data points to the grid point nearest to the specified point.

Grid points -- Evenly spaced points in the design plane located at integer multiples of the grid units from the global origin.

Grid references -- Reference crosses spaced at user-defined intervals on the grid.

Grid units -- The settings that specify the distance between adjacent grid points and the number of grid points between grid references.

Group -- A complex element (actually an unnamed cell) that is not defined in a cell library. Groups can be created to keep elements together, or to be copied for repeated placement in a design.

Handles -- Small squares drawn on (or sometimes near) elements to indicate that they have been selected. This provides an alternative to highlighting.

Hatch -- The process of constructing a set of evenly spaced lines in a closed area.

HDI (Heidi Device Interface) -- used for Heidi (and HOOPS) renderers and drivers; HDI is a scalable interface that allows hardware to do as much work as it is capable of handling.

HDTV (High Definition Television) -- Because of the larger picture size (16-by-9 display ratio for HDTV versus 4-by-3 for regular TV) and more horizontal picture lines, HDTV will have a higher quality display than conventional TV. Also, HDTV has cd-quality sound and involves digital transmission instead of analog.

Heidi (HOOPS Extensible Immediate Drawing Interface) -- Autodesk technology/interface for displaying and printing of 2D/3D CAD objects (used in AutoCAD, 3ds max, VIZ, Volo, DWF and HDI).

Help articles -- Text that displays in the Help window to explain particular concepts, features, and procedures in MicroStation.

Help topics -- A list of the areas covered by help articles that displays in the Help window.

Hidden line -- A rendering method that generates a surface model. See filled hidden line.

Hidden line removal -- The process of removing the lines in a 3D design that are hidden by surfaces. See edges hidden line removal.

High Sierra -- ISO 9660: a format for placing files and directories on CD-ROM.

Highlight color -- The color in which an element is displayed upon identification for manipulation.

Hole elements -- Elements whose area attribute is set to hole, as opposed to solid.

Host -- A computer that acts as a file server. Users at remote computers (i.e. client computers) are allowed to access information that's stored on the server, or host computer. See client.

HPGL (Hewlett-Packard Graphic Language) -- graphical data description language used primarily for communication with HP plotters. Language defined by the HP company.

HTML (HyperText Markup Language) -- the most commonly-used Web programming language. HTML codes are document formatting codes that tell browsers such as Mosaic or Netscape how to display the document you see on the screen. Free HTML software tools.

HTTP (HyperText Transfer Protocol) -- the set of language rules Web users must follow to communicate with each other. The phrase World Wide Web refers to the collective set of servers (computers) speaking HTTP.

Hypermedia -- "Hypertext" with links not only to text, but also to other forms of media, i.e. sounds, graphics, movies/video, animation.

Hypertext -- Text which allows users to "hyper-jump". Hypertext is basically the same as regular text, with one exception: hypertext contains connections within the text to other Web documents. The connections are denoted, generally, as underlined, colored text. The "documents" to which the hypertext connect may be local or remote, perhaps even in a different country.

IAM (Inventor AsseMbly) -- Autodesk Inventor assembly file format.

Identify -- To enter a data point on an element to distinguish it for manipulation or modification.

IDW (Inventor DraWing) -- Autodesk Inventor drawing file format.

IGDS -- Interactive Graphics Design Software, the software that ran on Intergraph VAX-based CAD systems.

IGES -- Initial Graphics Exchange Specification, a public domain, ANSI standard, neutral file format that is intended as an international standard for the exchange of product definition data between different CAD/CAM systems.

Incremental Dimensioning -- A method of expressing a dimension with respect to the preceding point. NOT a good idea, incremental dimensioning allows users to fall into a trap. If a single error in data is entered incorrectly at the beginning of a project, ALL points determined afterwards will have that amount of error built into them.

Indeo -- Intel's CODEC for video.

Input focus -- The settings or dialog box control upon which the next keystroke will act has the input focus.

Insert mode -- If on, new characters are inserted at the insertion point.

Insertion point -- The point, represented by a vertical bar, at which new characters are inserted.

Instance -- An occurrence of a shared cell that is placed in a design.

Internet Protocol (IP) -- the protocol which provides addresses needed to move packets of information across networks. IP addresses have two parts: a network identifier and a host identifier. See also TCP/IP.

Interpolation -- A function of a control whereby data points are generated between given coordinate positions.

IPT (Inventor ParT) -- Autodesk Inventor modelled part file format.

ISM (Image Support Module) -- an ARX application interface between AutoCAD and an image engine model.

ISO -- International Standards Organization.

ISO 9660 -- a format for placing files and directories on CD --ROM. Readable by both Macintosh and PC --compatible computers.

Isometric -- The standard view that shows top, left, and front facets of a design.

Isometric (Iso) view -- Standard view in a 3D design where the top, left, and front faces of a cube drawn orthogonal to the design cube axes are equally inclined to the screen surface.

Isometric lock -- The setting that, when turned on, forces each data point to lie on the isometric drawing plane.

JAVA -- An object-oriented , Web programming language, similar to C++, developed by Sun MicroSystems. JAVA applications are compiled into Java bytecode, executable on any java-enabled browser, i.e. browsers which have the "Java Virtual Machine" Thus, JAVA will run the same on any operating system. JAVA applications, technically, are stand-alone programs, whereas JAVA applets are code snippets, designed to run within Web pages.

JAVA Applets -- Small programs written in JAVA that produce various special effects, which are embedded right into the Web pages. When someone accesses a Web page with applets, the applets automatically download with the page: All that is needed to view the effect comes with the page itself, making applets independent of the eccentricities of various operating systems. This design feature makes applets particularly desirable for multimedia applications, which typically are very platform --dependent.

JAVA Beans -- Component API's allowing Java applications to run in other frameworks, e.g., Microsoft Word.

JavaScript -- Resembles Java (much easier to learn), but runs (is interpreted) on the client (user) side, not the host/server. (simple code example) +/ --'s of Javascript.

Joints -- Intersections of multi-lines.

JPEG (Joint Photographic Experts Group) -- Compressed, still --image graphics files. There are two major types of JPEG; progressive, where a fuzzy images emerges into 100% decompression/clarity, and baseline or standard, where a clear image is revealed, part-wise, top-down. Progressive, or interleaved, decompression looks better over networks. See CODEC.

Key frame -- A "complete" video frame, containing all the image detail, not just the changes from the previous frame.

Key-in -- An instruction entered into the Key-in window to control MicroStation. Most key-ins have GUI control equivalents.

Key-in window -- A window used to scroll through lists of key-ins, construct key-ins, and submit key-ins to MicroStation. Opens when Key-in is chosen from the Utilities menu.

Keypoint -- Points on an element to which a tentative point will snap when Snap Lock is on activated within Keypoint mode.

Keypoint snap mode -- If active, entering a tentative point close enough to an element causes the tentative point to snap to a keypoint on the element.

Kiosk -- An electronic "newsstand" or booth. Electronic kiosks are often used for mall directories, where users can touch a screen to find the location of a particular shop.

Kodak Photo CD ("PCD's") -- Photographs/images are "printed"/digitized on CD's. Your Photo CD comes with a contact sheet, showing small pictures of each image on the disc. You can keep adding pictures to the CD. To view the CD images, you need a viewer. Nowadays, many multimedia programs can import these already-digitizied image files into documents.

LAN (Local Area Network) --A privately-operated communications system interconnecting computers and communications equipment over a limited geographic area, usually 5 miles or less. LAN's enable local resource-sharing (printers, files, etc.).

LBS (Location Based Services) -- Applications based on the current position of a user (mobile, GPS, etc.).

Level -- In the MicroStation DGN file format, the number of levels is unlimited, and the minimum number of levels is 1. You can delete unused levels. All levels are named and have default colors, line weights, and line styles, providing the foundation for numerous enhancements. An important benefit of the level system is the ability to standardize level structures across DGN files.

Level filter -- Filtering the level entries in the list boxes in the Level Display and Level Manager dialog boxes allows you to search and sort these entries.

Level group -- A set of levels that can be collectively manipulated and displayed.

Level lock -- The setting that, when turned on, prevents selection or manipulation of any element that is not on the active level.

Level structure -- The hierarchical organization of levels after they are grouped.

Level symbology -- A view setting that, when turned on, causes all elements on a particular level to be displayed with the same element symbology.

Library -- See cell library.

Light cell -- A cell containing a light source.

Light source -- A point in a design that is not visible, but casts light that is visible in a shaded view.

Line string -- An open graphic element composed of line segments connected at the vertices.

Line style -- A part of the symbology of an element, for example, whether a line is solid, continuous dashes, dots and dashes, and so on. Each element can have its own line style or each can be defined by separate symbology. You can create custom line styles.

Line style component -- Any of the properties such as stroke patterns, point symbols, and compound components that apply to a line style.

Line style definition -- A line style name and its corresponding line style components stored in a line style library.

Line style modifiers -- Properties that can be applied to a line style to modify it as elements are placed, without requiring separate line style definitions.

Line terminator -- A cell placed at the end of an open element, oriented in the direction of the element. A commonly used line terminator is an arrowhead placed at the end of a line segment.

Line weight -- An index in the range 0 to 31 that designates the weight or thickness of the lines used to draw or plot a graphic element. Each element has its own line weight.

Linear patterning -- The repetitive placement of the active pattern cell along a line, line string, shape, arc, circle, ellipse, or curve element.

Linkage mode -- The setting that determines how the active entity is treated when a graphic element is linked to it. Settings include new (unique row required for each linkage), duplicate (same row used for each linkage), information (no table rows added or deleted when linked element is copied or deleted), and none (no linkages can be created).

List box -- Rectangular areas in which files, directories, or other items are listed for selection or reference.

Locate -- To find an element in the DGN file.

Locate tolerance -- A setting that determines the size of the area surrounding the element selection or identification pointer in which MicroStation can locate elements.

Locks -- Settings that you selectively enable or disable. Locks affect the way MicroStation interprets and reacts to your input.

Lossy/Lossless Compression -- See compression.

Luminance -- A color's brightness.

Machine Code -- Code obeyed by a computer that needs no further translation.

Macro -- A group of instructions that can be stored and recalled to solve a recurring problem.

Macro -- A software program that automates an often-used, usually short sequence of operations.

Macro language -- Used to represent macro code. A dialect of BASIC with MicroStation-specific extensions.

MagneticTape -- A tape made of plastic or mylar that is covered with magnetic particles. It stores information by selective polarization of portions of the surface.

Manipulate -- To copy, move, rotate, scale, mirror, or delete an element or group of elements.

ManualDataInput (MDI) -- A mode of control that allows the operator to input data into the control system, the data input is identical to the data that can be input by other means such as tape or DNC.

ManualPartProgramming -- The preparation of a manuscript in machine control language and format to define a sequence of commands for processing by a CNC machine.

Manuscript -- A written or printed copy, in symbolic form, containing the same data as that punched on cards or retained in a memory unit.

Mark -- See dimension mark.

Mask -- An area of a reference that is not displayed.

Master units -- The largest units in common use in a model.

Material assignment table -- Assigns a material to elements on a level(s) with a color(s) in the design.

Material characteristics -- Information for mapping color indices and levels to surface characteristics, such as reflectivity, finish, and color.

Material definition -- The attributes related to color, texture, transparency, and finish that may be applied to surfaces.

Material palette -- Contains material definitions including pattern maps, bump maps, or combinations of both.

Material tables -- Files that contain material characteristics. With material tables, simple textures or materials such as “flatmetal” or “plastic” can be simulated as part of a final rendering.

Matrix menus -- Paper (mounted on the surface of a digitizing tablet) menus that contain menu blocks of a fixed size organized in rows and columns.

Maximized -- When a dialog box or window is drawn to the largest scale that will fit on the selected paper size.

MCI (Media Control Interface) -- Multimedia commands/calls comprising Windows API (Application Program Interface).

Mechanical Desktop (MDT) -- A mechanical 3D CAD application by Autodesk; based on AutoCAD kernel. Now part of Autodesk Inventor Series.

Mechanical dimension format -- Dimensions that conform to mechanical design conventions.

Memory -- An organized collection of storage elements into which a unit of information consisting of a binary digit can be stored and from which can later be retrieved.

Menu -- One method for activating a MicroStation command, including pull-down menus, tool boxes, function key menus, and paper menus.

Menu block -- An area in a paper (command or matrix) menu defining a region that is selected to perform specific task.

Menu cell -- A cell in a cell library that contains the special information needed for a paper menu.

Menu control information -- Information specified with user commands that controls how menu actions are taken when menu options are selected.

Menu DGN file -- A MicroStation DGN file in which menu cells are created for custom menus.

Menu item -- Any of the list of options on a pull-down menu.

MicroStation Development Language (MDL) -- Allows programmers to execute C language code within MicroStation.

MIDI (Musical Instrument Digital Interface) -- Rather than recording sounds, MIDI instruments/software record finger action: what note is being played, when, and for how long. To playback MIDI files, you need a sound card that can interpret the MIDI note data, either by creating the tones themselves (FM-synthesis) or playing back sounds that are stored internally (waveform). "General MIDI " is an emerging standard for MIDI playback. Alphabetical listing of MIDI works by classical composers.

Mirror -- A manipulation that reverses the geometry of graphic elements about a horizontal, vertical, or specified arbitrary line.

MMX (Multimedia Extension) -- A multimedia accelerator in Intel's Pentium processors that speed media and communications processing 40 to 60%. Standard Pentiums move 1 byte of data at a time into the CPU for processing. In contrast MMX Pentiums move 8 bytes, all processed simultaneously.

Mnemonic access character -- The underlined character in each menu name and menu item.

Model -- A DGN file component that contain elements. Design models can be either 2D or 3D, but they are most useful in their 3D form. Sheet models, which are flat and used for drawing composition, are ordinarily 2D. By default, the view windows of a design model have black backgrounds, and the view windows of a sheet model have white backgrounds.

Modem -- A hardware device that converts waveform (analog) data to digital. MOdulation converts analog to digital; DEModulation converts digital to analog. Hence, MODEM. Network transfer speed comparison.

Modifier key -- The <Ctrl>, <Alt>, and <Shift> keys, which may be used in conjunction with the function keys to create new function key definitions.

Module -- A subdirectory tree under MicroStation's directory that contains data files in the sample workspaces.

Monument point -- A known landmark point in the design plane. Monument points are used to orient references.

MPEG (Motion Picture Experts Group) -- Compression algorithm that allows for high compression.

MSCATALOG -- A table that must be contained in every non-graphical database with linkages to elements. MSCATALOG contains information associated with each table that is used by the database server.

Multi-line element -- A set of two or more parallel lines treated as a single object, commonly used for drawing walls in floor plans. A multi-line element can be defined to include up to 16 separate lines, each with its own symbology, level, and class.

Multimedia – Presentation of information that includes video, sound, images, text, animation, and/or other computer generated content.

Multi-session -- A CD-ROM drive that can read CD's that have been updated/changed. As CD's are updated, new directories are written, with the newer directories written further and further out to the edge. Multi-session CD-ROM drives begin searching for directories by reading out to in, thus can find the furthermost directory. Single-session CD-ROM drives begin searching for directories from the inside out, thus only the first directory nearest the hub would be encountered.

Multi-snap -- A list of snap modes applied sequentially. You can define three multi-snaps.

Multi-thread -- describes a program that is designed to have parts of its code execute concurrently.

Nested -- When part of a cell is used as part of an additional cell.

Nested reference attachments -- MicroStation provides live nested reference attachments as an alternative to flattening all reference attachments in the active model. When this option is enabled, changes to reference attachments in designs that are referenced to other designs are reflected the next time either the active model's views are updated or the file is reopened.

Newsgroups -- A newsgroup is like a bulletin board: any subscriber can post a message to the newsgroup, and each subscriber can read any or all of the messages. Newsgroups can be useful for gathering information on subjects that are popular among other Internet users. The most active newsgroups are usually those focused on high --tech topics, topics of concern to academics or students. However, newsgroups devoted to entertainment and non --technical professional topics often have a significant number of regular participants. You can read news using the Netscape browser, or through a variety of news reading programs.

Node -- Shorthand for text node. Also a computer in a network.

Non-coincidental reference attachment -- A non-coincidentally attached reference is offset, rotated, or scaled from the active DGN file.

Non-graphic database -- A collection of tables representing objects that, unlike DGN file elements, are not conveniently represented in pictorial form.

Noun-verb -- A manner of operating MicroStation; to select an element in the design before selecting a tool to act upon it.

NURBS (Non-uniform Rational B-Spline) -- a method of geometric description of free --form surfaces used for modelling of complex shapes based on spline curves.

ObjectARX -- Object library for building ARX applications for AutoCAD in the C++ language.

OCR (Optical Character Recognition) -- scanning/process for machine print recognition. Compare to ICR.

Offset -- A displacement in the axial direction of the tool equal to the difference between the actual tool length and the programmed tool length.

Offset -- In a compound line style component, the value that specifies the distance measured perpendicularly from the working line to where the component is displayed.

OLE (Object Linking and Embedding) -- transferring objects between Windows applications and keeping links between the applications.

OLE (Object Linking and Embedding) -- Windows' "magic" to transfer objects from one program "document" to another. The process involves copying the selected object to the clipboard, then switching over to the receiving document and pasting. Paste Linking (available as a Paste Special option), plants a trail back to the original/source document so that when the original changes, you see the changes in the receiver. Paste Embedding, the default paste mode, places a copy of the original into the receiver. Because the two programs are not linked, any changes to the original are not reflected in the receiver.

Opaque -- A type of fill that is displayed as a solid shape of the active color.

Open B-spline -- A B-spline that starts at its first pole and ends at its last pole; its ends do not meet.

OpenGL -- 3D graphic programming API written by Silicon Graphics. Allows programs to interface and use built in high speed 3D graphic routines on graphic cards. The standard for high end 3D modeling and recently adopted by Apple Computers as their standard 3D interface.

Optical Storage Unit -- CD-ROM drive.

Optimization -- The construction or reduction of 3D model geometry with the goal of reducing polygon count; and the compression or reduction of bitmap resolution in order to increase render times. Optimization of digital models is especially critical for realtime model rendering.

Option menu -- A menu in a dialog box that allows only one value to be selected.

Optional Stop -- A miscellaneous function similar to Program Stop(M01) except that the control ignores the command unless the operator has previously pushed a button to validate the command.

Oracle linkage -- See database linkage.

Order -- Integer value associated with a B-spline that determines the smoothness of the B-spline and the number of points in the control polygon, influencing the path of the curve at a given position. The higher the order, the smoother the curve, and the more points in the control polygon influencing the path of the curve.

Origin -- See cell origin or global origin.

Orphan linkage -- Linkages without associated rows in the database.

Orthogonal -- Constructed with right angles or perpendicular lines. An orthogonal shape contains only right angles.

Outline -- A type of fill that displays lines in the active color forming a wireframe view of the closed element.

Output -- Data transferred from an internal storage unit to storage or an 

output device.

Overlap -- A fence selection mode that includes only the elements inside or overlapping the fence.

Override -- The mode that allows you to override the Snap Mode.

Overwrite mode -- The mode of text entry in which each new character overwrites an existing character.

Panning -- To scroll a view over the design plane.

Pantone (Pantone Matching System) -- A standard palette of exactly defined color hues.

Paper menus -- Menus printed on paper and mounted on the surface of a digitizing tablet. The Command button on the tablet cursor is used to select an item on a paper menu.

Parabola -- A plane curve generated by a point moving so that it's distance from a fixed second point is equal to its distance from a fixed line.

Parabolic interpolation -- Control of a cutter path by interpolation between three fixed points, with the assumption that the intermediate points are on a parabola.

Parallel ports -- Also called "printer ports", parallel ports transfer several bits simultaneously. Thus, they are faster than serial ports. However, they can only send, not receive, information; whereas serial posts can handle 2 --way transmission.

Parallel projection -- A view of a 3D design in which each element is projected to the screen along a line parallel to the Z-axis of the view. (Compare perspective projection.)

Parameter -- See settings.

Particle tracing -- Provides photo-realistic lighting solutions. An alternative to traditional radiosity solving, it has significantly lower memory requirements.

Partition -- To separate the digitizing tablet into two regions.

Path configuration variable -- A type of configuration variable that tells MicroStation in which directories to find files, MS_DEF, for example.

Pattern element -- An element with a class attribute of pattern. It can be placed only with a patterning tool.

Patterning -- See area patterning.

PCI (Peripheral Component Interface) -- A very fast I/O bus (with potential of 132 Mbps transfer rate).

PCMCIA -- Personal Computer Memory Card International Association.

PDF -- Adobe Acrobat's Portable Document Format.

PDF -- Adobe's Portable Document format. Files of this format are often referred to as PDFs.

Perspective projection -- View of a 3D design in which each element is projected to the screen along a line that intersects with the eyepoint. Elements that are further from the front of the view thus appear smaller. (Compare parallel projection.)

Phong shading -- A method of shading a rendered image that recalculates the color for each pixel in the final image. Phong shading produces high quality images but increases rendering time.

Picture data -- In file exchange, the graphical information that draws a picture.

Pixel -- PICture ELement, the smallest dot of light that a monitor can display.

Pixels -- The tiny dots comprising a picture.

Place SmartLine -- The tool used to place a line, line string, shape, arc, or circle or a combination thereof.

Plotfile -- The file generated by MicroStation that contains plotter commands that, when sent to an output device, will cause it to print out the desired portion of the design plane.

Plotter driver file -- A file containing information needed to generate plotfiles for a particular type of output device. These file have the form *.PLT.

PLT (PLoT file) -- A printer output file with instructions for a specified plotter type, usually in the HPGL or HPGL/2 format.

PNG (Portable Network Graphics) -- A proposed replacement/improvement for the GIF format. It allows for both up to 8 --bit and 8x8x8 palettes, variable transparency, gamma correction, better interlacing and better compression than GIF. It does not, however, allow for animation. PNG has only recently seen support from Netscape and IE. Macromedia's Fireworks uses PNG as its native format. See: http://www.libpng.org/pub/png/

Point -- See data point, tentative point, or active point.

Point cell -- A cell with a single, snappable point. Point cells are commonly used for symbols and to establish monument points. The snappable point in a point cell is the cell origin. Point cells are always placed relative to the active level with the active symbology.

Point curve -- A type of curve that has no settings that control the curve's shape.

Point element -- A special case of a line element that has no length.

Point light -- A type of light cell that radiates light in all directions from a single location.

Point light source -- Light emanating from a point. Point light sources illuminate surfaces differently depending on their orientation.

Point of intersection -- The point at which two non-parallel lines intersect, or would intersect if the lines were extended.

Point symbols -- A type of line style component.

Pointer -- The small icon on the screen that moves in response to user inputs and indicates the position where input is supplied to MicroStation.

Pointers -- Variables used by MicroStation and other applications to place, locate, and process elements in the DGN file.

Polar array -- The set of copies of an element placed in a circular pattern in a design.

Polar coordinates -- The coordinates used in a spherical (auxiliary) coordinate system or in AccuDraw to specify distances and angles.

Pole -- A vertex of a B-spline curve.

Polygon hidden line -- A type of rendering performed by MicroStation.

PopSet -- A feature that prevents the display of the selected tool's settings window when you are finished adjusting its controls. PopSet allows you to reclaim valuable screen real estate and reduce pointer movement.

PowerSelector -- A tool that simplifies the process of defining attribute-based element selection criteria.

Precision input key-ins -- A means of entering data points at precise locations either by specifying the coordinates or by specifying the distance from the most recent data point or tentative point.

Preferences -- Settings that customize MicroStation to your particular machine and desired mode of operation.

Presentation software -- Packages, such as Microsoft PowerPoint, which allow users to create "electronic overhead transparencies". Typically easy to use, presentation software does have all the full multimedia capabilities that you will find in authoring software.

Primary elements -- Elements whose class attribute is primary (as opposed to construction.)

Primary key -- The MSLINK column in a database with linkages. Any row can be uniquely specified solely by its MSLINK column value.

Primitive elements -- The simplest type of element.

Private key -- An encryption/decryption key known only to the parties exchanging messages.

Product-definition data -- In file exchange, graphical information that describes a design.

Profile element -- A planar cross-section of an actual element that can be projected or rotated to draw the final element.

Project -- A type of configuration variable file that is set by a site or project manager to facilitate using MicroStation in workgroups. A project can also be the component workspaces and the data files used for a particular discipline or undertaking.

Projection -- A type of action that may be taken on a planar profile element formed by extruding a line string, curve, shape, ellipse, complex chain, or complex shape to create a surface of projection.

Prolog -- Text file used to provide the header for a PostScript file.

Prompt -- The text in the status bar that tells you what to do next.

Properties -- Element criteria that may be searched, including the area attribute (Solid or Hole), whether an element can be snapped to, whether it is locked, and whether it has been modified.

Public domain -- Software is available for unrestricted use, and can be copied freely and even renamed and resold.

Public key -- With a private key derived from the public key you can effectively encrypt messages with a digital signature.

Push Web technology -- Also referred to as "Web-casting" or "channel-casting", this technology publishes/broadcasts personalized information to subscribers. Then, instead of using bookmarks and search engines to pull down information, users would run a client application that gets updated with data that is "pushed" down by a server.

RAID (Redundant Array of Independent Disks) -- Stacked hard drives.

RAM (Random Access Memory) -- Cache RAM (fast RAM to match the speed of microprocessors); flash RAM (fast, permanent memory on PCMCIA cards); DRAM (dynamic RAM); SRAM (static RAM) ; SDRAM (synchronized DRAM); VRAM (video RAM); CDRAM (cached DRAM)

Rapid prototyping -- Rapid prototyping is the process of generating an object directly from its digital representation in a CAD/CAM system. The main benefit of this process is reduced time to produce a prototype, which in turn speeds up the entire development process.

Raster background -- A bitmapped picture that can be used as the backdrop for a rendering.

Raster fonts -- Fonts used to display text in the status bar, dialog boxes, tool boxes, and each view window's title bar.

RealAudio -- Real-time, live audio on the Web. RealAudio highly compresses sound files to ship down the network. After front --loading a portion of the recording, the receiving player starts, pulling in remaining portions. This lets users begin listening as the sound file is being downloaded, hence "real-time", rather having to wait until downloading is complete. You can take a closer look/"listen" at http://www.real.com.

Real-time compression -- Compression of movies as soon as they come into the computer -- also known as one-step capture. See capture, video.

RealVideo -- Delivers "broadcast-quality" video over the Internet in real-time. The software operates over modems operating at 28.8 Kbps and up. The beta version is available at http://www.real.com.

Receiving application -- In file exchange, the application into which a file exported from MicroStation will be imported.

Record -- The equivalent of a row in a database table, representing an individual object.

Rectangular ACS -- An auxiliary coordinate system that uses standard (Cartesian) axes.

Reference -- A model attached to and displayed with the active model for printing or construction purposes. A reference cannot be modified. You can attach, as a reference, a model that resides in either the open DGN file or some other DGN file.

Relational database -- A software package that stores, manipulates, and reports on non-graphical information. It acts on collections of tables or files that represent objects, their properties, and relationships between the objects.

Rendering -- To produce an image of a 3D model that looks more realistic than a wireframe image. Includes hidden line and surface shading.

Report files -- Text files that report output from MicroStation.

Report table -- A file containing the database attributes of elements in a fenced area. A report table is structured identically to the master table from which the data was derived.

Reset -- A placement action that, with most tools, backs up one step. In some cases a Reset operation completes an action; in other cases, it cancels an action or rejects an identified element.

Reset button -- The button on a mouse or digitizing table cursor that is pressed to enter a Reset.

Resetting -- Entering a Reset.

Resize border -- The frame around each view that permits the view to be resized. When the pointer is placed on the resize border, it becomes a double arrow, and that border can be pulled or pushed to expand or contract the size of the view.

Resolution -- The clarity of the displayed/printed image. The more pixels/dots per square inch (dpi), the finer the detail (higher resolution). Color resolution comparison.

Resolution -- The number of addressable points across a given area. For example, output device resolution is measured in lines per inch, while screen resolution is usually given with two numbers indicating the number of pixels across the width and height of the largest image that can be displayed.

Resource -- The default specifications for menus and dialog boxes.

Resource file -- File containing the default specifications for dialog boxes.

Reverse engineering -- During reverse engineering, a point cloud typically acquired using scanning techniques is used as a basis for constructing 3D CAD surface data from a physical model. This enables a considerable speed-up of the design and construction process as well as an early quality control of the physical model through comparison of physical object data with CAD surface data. This means that inaccuracies in the model can be eliminated during an early stage of the process.

Revision -- A specific version of a saved DGN file. With each file save operation, Design History captures the state of the DGN file at that moment by recording your user ID, the current time and date, the incremental changes to the elements in the design, and optional comments.

Revolution -- A type of action that may be taken on a planar profile element formed by rotating a line string, curve, shape, ellipse, B-spline curve, complex chain, or complex shape.

RGB (Red-Green-Blue) -- The primary colors composing light. Applied to color monitors, for example.

RIFF (Resource Interchange File Format) -- File format for storing sound and graphics so they can be played by different types of computers.

Right isometric -- The view showing the top, right and front faces of a cube.

Row -- See record.

RTF (Rich Text Format) -- A file format developed by Microsoft; contains formatted documents to be transferred between applications.

Rubberbanding -- See dynamic update.

Sampling -- When converting video or audio waves to digital format, digitizing software picks out points along the wave and records or "snapshots" these points. These "snapshots" can then be replayed in much the same way that motion pictures are recreated from the individual frames. The higher the sampling rate, i.e. the more snapshots/points, per unit time, the more accurate the computer's representation of the wave.

Saved -- The kinds of settings, such as working units and view configuration, that are kept between sessions.

Saved view -- A named view definition saved in a DGN file for later recall or for attaching to another model file as a reference.

SCADA -- Supervisory Control And Data Acquisition.

Scale -- To resize an element or elements by the active scale factors. In plotting, the ratio between distance in the DGN file master units and distance represented on the output device.

Scan converter -- See Video Scan Converter.

Scanner -- A computer device which "reads" text or graphics and converts them into digitized documents/files. Most scanners work by lighting an image and measuring the light reflected through it. The scanner them converts the reflections into distinct voltages which are, in turn, transformed into patterns of dots. The resolution or clarity of the image is measured in dots per inch. See related: Resolution, Graphic Considerations for the Web

Screen element -- One of the pieces that make up MicroStation's graphical user interface, such as the desktop, a window border, or a button.

Screen menus -- Pull-down menus, tool frames, dialog boxes, and sidebar menus.

Screen partition -- The area of a digitizing tablet in which the tablet cursor controls the screen pointer normally across the entire screen. See partition, compare to digitizing partition.

Screen saver -- A visual program using moving graphics to prevent monitor burn-in.

SCSI (Small Computer Systems Interface) -- A very fast, versatile parallel port allowing a computer to connect (or "daisychain") up to 7 peripheral devices, like laser printers, CD-ROM drives.

Search "engines"/tools -- Programs which allow you to search through Web pages by keyword or subject. See: Webmaster's Guide to Search Engines

Search criteria -- Element attributes for which MicroStation can search.

Section -- Part of a drawing that shows interior detail that is too complex to see clearly in a wireframe view.

Seed DGN file -- A template file that contains the appropriate default settings and attributes.

Seed sheet model -- A seed file from which sheet models can be created.

Select -- To distinguish an element, identify a list box entry on which to operate, or activate a tool or view control.

Select range -- See locate tolerance.

Select settings window -- Used to adjust the active settings and select a drawing tool.

Selection set -- A group of selected elements. Selected elements are displayed with handles.

Self-paced -- The student can start and finish the program at any time, at his/her convenience. It typically involves no moderation/interaction with an expert/instructor. Examples include most cd-roms, video-tapes, cassettes, etc. See Distance Education

Sending application -- In file exchange, application that created a file that is to be imported into MicroStation.

Separator bar -- A horizontal line across a menu that logically subdivides menu items in the same menu.

Serial Ports -- Used for 2-way communication, serial ports transfer data one bit at a time. Many devices, including modems, scanners and laser printers, connect to serial ports. Contrast to parallel ports.

Server model -- Defines the interaction between MicroStation, a database package, and the database server.

Server-Side Markup (SSM) -- a "tag" embedded in the Webpage that gets interpreted "on the fly"/processed by the server each time the page is requested.

Settings -- Values that determine how MicroStation displays a design or handles user input.

Settings file -- An import or export file that stores all settings for a particular conversion as they were when the settings file was created or last saved. Also, a type of module data (“.stg” files) that specifies active settings and drawing tool selections; used with the Select Settings window.

Shadow map -- A file containing an image created in the first step in rendering shadows, used to determine whether surfaces are illuminated or in shadow.

Shape -- A closed primitive element composed of linear segments.

Shared cell -- A cell whose elements are stored only once in the DGN file, regardless of how often the cell is placed. Any change made to one instance of a shared cell reflects in all instances of that shared cell.

Shared cell definition -- The elements comprising the shared cell.

Shareware -- "Try before you buy" software. The author retains full rights to the package. It may be copied at will, but shareware cannot be used at will. There is generally a limited period of use granted without fee, commonly 30 or 60 days. After that period, the user pays a licensing fee to continue using the software.

Sheet file -- A 3D DGN file in which views of the model file(s), including visible edges and sections, are attached.

Sheet model -- A type of model that serves as an electronic drawing sheet. It typically consists of design model references that are scaled and positioned to create a printable drawing.

Shockwave -- An add-in to MacroMedia Director that lets you create highly-compressed interactive animations and movies for Web pages. An easier-to-use, vector-based Web-animation program is Flash, also from Macromedia

SHX -- A compiled file of font or shape definitions for AutoCAD (or other Autodesk application). An Autodesk format.

Sidebar menu -- A menu that displays onscreen and presents commands for selection in a text-based, hierarchical form. Although sidebar menus are still supported, tool boxes have taken their place.

Simultaneous engineering -- Refers to the cross-departmental/cross-company cooperation involved in engineering tasks. The specific activities are carried out individually, with the goal of parallel execution so that processes that have no dependency on other processes may be carried out at the same time. This can be achieved by the use of a central CAD database which all of the involved parties may access and edit, and which is the basis of communication. This results in a rapid distribution of feedback from different departments and so a reduced number of changes that are needed to achieve the final product.

Single-shot -- Selecting a tool for one-time use by double-clicking it.

Sink -- To put a window just below the lowest view.

Site -- A type of configuration variable set by a system or site manager to facilitate using MicroStation in workgroups.

Sky opening -- Not a light in the traditional sense, but acts as a control when using Solar, Distant and Sky lights. A sky opening generates more efficient solutions for indoor scenes lit with sky or sun light through an opening such as a skylight, window, or door. Processing time is reduced because testing for shadows is carried out in the directions of the sky openings, as opposed to testing the entire sky.

Slab -- A volume of projection with a rectangular cross section.

SmartLine -- See Place SmartLine.

Smooth shading -- A method of shading a rendered image by calculating the color of the polygons at their boundaries and blending those colors across the polygon interiors.

Snap -- Use of the tentative point to position a data point at an exact point on the target element. Tentative points snap to an element when Snap Lock is on.

Snap divisor -- The setting that determines the positioning of keypoints on linear segments. The number of keypoints per segment is one greater than the snap divisor. If the snap divisor is one, only endpoints of a linear segment are keypoints. If the snap divisor is two or a multiple of two, the center point is also a keypoint.

Snap lock -- The setting that, when on, causes MicroStation to try to find an element or element intersection to snap to when a tentative point is entered. See also keypoint snap mode.

Snap lock divisor -- The number of keypoints on each segment of a linear element plus one.

Solar light -- Lighting that approximates illumination from the sun. MicroStation allows solar light to be approximated at any time of day between sunrise and sunset, on any date, and at any latitude.

Solar time stamp -- You can display the current solar time and date information while rendering a view. This lets you produce solar studies, for example, in which the time and date appear. A special cell, SLRTIM, contains enter data fields into which you can place variables that are replaced with the required information which then appears during rendering.

Solid -- A type of complex element specific to 3D, along with surfaces.

Solid of projection -- A solid formed by moving a closed planar shape along a linear trajectory to a second parallel plane. The shape at the target plane is rotated by the active Angle and scaled by the active Scale. The profile elements are connected at their keypoints by linear rule elements.

Solid of revolution -- A solid formed by sweeping a closed planar element around an axis of revolution. The profile elements are connected at their keypoints by circular arc rule elements.

Sound card -- An add-in circuit board that once installed, enables the computer to accept audio input from a microphone, edit/trim/mix recordings, play sound files stored on disks or CD --ROM's, and produce audio output through speakers or earphones. For output, sound cards can 1) create or synthesize sounds, like a keyboard/synthesizer, and 2) play previously --recorded sounds, like a tape recorder/player. See also audio.

Source view -- A view created, set up, and saved to use as a model view.

Spherical ACS -- Auxiliary coordinate system in which positions are determined by one magnitude and two angles.

Spot light -- A type of light cell that casts a conical beam of light.

SQL -- Standard Query Language, a simple, powerful language that is the industry standard for database access and data manipulation.

Stacked dimensions -- A group of dimensions that have at least one witness line in common.

Standard views -- The eight commonly used views of a 3D design (Isometric, Right Isometric, Top, Bottom, Left, Right, Front, and Back).

Startup application -- The MDL application that is active when a DGN file is not opened.

Status bar -- The strip at the bottom of the application window (or screen) that displays messages, prompts, and status information. The area on the screen where messages such as tool prompts, errors, and the current status of MicroStation settings (snaps, levels, element selection, and DGN file disk status) are displayed.

STEP -- (STandard for Exchange of Product model data) -- File exchange format for 3D CAD data used in mechanical industry. Specified by US institute NIST (and ISO 10303).

Stereo imagery -- Human vision uses the difference between the image seen by the left and right eyes to perceive distance. MicroStation can duplicate this effect by rendering two different images from slightly differing camera positions, and then superimposing the two images on one screen in different colors. When the composite image is viewed with 3D glasses, it appears to have depth.

Stereolithography format -- From a CAD solid model a model in a format compatible with stereolithography machines may be produced. The format is a triangulated approximation of the original surface model. The physical model is then produced by laser-curing of resin in a layered build-up.

Stream angle -- A setting that causes a sampled stream point to be saved if the angle formed by the sampled point and the two most recently sampled points exceeds the setting.

Stream area -- A setting that causes a sampled stream point to be saved if the area of a triangle formed from the sampled stream point and the two most recently saved points exceeds the setting.

Stream delta -- A setting that determines when the pointer position is a sampled point. If the distance from the previous sampled point to the current pointer position is greater than the stream delta, the point is considered a sampled point and the stream angle, stream area, and stream tolerance settings are tested to see if the point should be recorded as a data point.

Stream tolerance -- A setting that causes a sampled stream point to be saved if the distance from the sampled stream point to the most recently saved point exceeds the setting.

Streaming audio/video -- Capability to begin playing media on the client side before it has fully downloaded from the server side, i.e. begins playing as it is coming in, "in real-time." The major players are RealNetworks (RealAudio - the industry standard) and Apple (" streaming" QuickTime).

Stroke pattern -- A line style component comprising dash strokes and gap strokes.

Stroke tolerance -- The setting that determines the size of polygons into which curved surfaces are broken for rendering.

Style -- A multi-line definition or set of dimension attributes that can be saved in a settings file for later recall.

Subunits -- Units that master units are divided into in the working unit definition. For example, if master units are feet, a convenient subunits setting would be inches. The number of subunits per master unit and a one or two character abbreviation for the subunit name is specified in the working unit definition.

Suffix -- See extension.

Surface -- A 3D geometric construction that can partition space but cannot enclose a volume.

Surface description -- A relationship between an element color and a surface color, reflectivity, and roughness. See also material tables.

Surface description file -- The file that contains surface descriptions for one or more element colors. The surface description file is used by MicroStation's surface shading.

Surface of projection -- A surface formed by moving a planar profile element along a linear trajectory to a second parallel plane. The profile at the target plane is rotated by the active Angle and scaled by the active Scale. The profile elements are connected at their key points by linear rule elements.

Surface of revolution -- A surface formed by sweeping a planar profile element about an axis of revolution. The profile elements are connected at their keypoints by circular arc rule elements.

Surface shading -- Process of creating a lifelike image where the visible surfaces are filled with colors calculated from their surface descriptions and the ambient and point light sources.

SVGA (Super-VGA) -- Video monitor/card supporting 640x480 resolution (or greater) with 256 colors or more.

Symbol -- A character placed from a MicroStation symbol font.

Symbol font -- A font that contains special use geometric constructions rather than alphanumeric characters. A typical use is to hold symbols for dimension line terminators and dimension marks, and geometric tolerancing.

Symbol library -- MicroStation uses the term cell library to refer to what may be known as a symbol library in other applications.

Symbology -- See element symbology, level symbology, or attributes.

Synchronous -- Communication/interaction in real time, i.e. at the same time, thus lending itself to the kind of immediacy of communication experienced in a classroom. This may be done using the telephone, chat rooms, whiteboards, etc. See Distance Education

Synthesized -- Sounds created by computer circuitry. See wavetable and FM synthesis. See also MIDI .

System -- Type of configuration variable.

Tag set -- Set of associated tags.

Tag set definition -- Information that specifies, for each tag in a tag set, several tag attributes, such as whether the tag is displayed and its default value, if any.

Tags -- Non-graphical attributes that may be attached to elements drawn in designs.

TCP/IP (Transmission Control Protocol/Internet Protocol) -- A set of communication standards through which different kinds of computers on the Internet communicate together; the "language" of the Internet.

Teleconference -- A phone meeting where callers can both see and hear each other. Network transfer speed comparison. See also: videoconferencing.

Tentative button -- The button that is pressed to enter a tentative data point. The tentative button may also shift the location of the AccuSnap selection.

Tentative point -- A graphic input that is used to preview the location of the next data point, define a point of reference, and/or create an association point. Tentative points may appear with AccuSnap.

Terminal Control Block (TCB) -- A global data area of memory in which MicroStation stores settings.

Terminator -- See dimension line terminators or line terminator.

Text attributes -- The color, weight, font, height, and width of text.

Text element -- MicroStation places text in DGN files as a distinct type of element.

Text files -- Files that contains no special codes or commands, such as bold, italics or graphics, only text. Text files, unlike binary files, can be read without any special software. See binary files.

Text node -- A group of multiple text elements grouped in a complex element. MicroStation automatically forms a text node when multi-line text is placed.

Text node lock -- A setting that, when turned on, forces subsequently entered text to be attached to empty text nodes. If an empty node is not available, no text is placed.

Text style -- Comprises a group of text attributes such as font type, width, height, and color. Text styles allow you to place text within a model file in a consistent and automated manner. The fonts that are supported natively in MicroStation are True Type and AutoCAD fonts (.shx).

Text-to-Speech -- Voice synthesizers that "read" computer text. First used to read screens for blind computer users, text-to-speech is becoming increasingly popular for children's games. For more information: Visit AT&T's Advanced Speech Products Group (http://www.att.com/aspg)

TIFF (Tagged Image File Format) -- A cross-platform file for storing high-quality graphics.

Tile -- To arrange views and tool boxes so that they do not overlap.

Toggle -- A type of setting that has only two states, such as off and on. Used as a verb, to change the state of a toggle.

Tool -- A program, following defined protocols, that provides a service.

Tool box -- Icon-based screen menus from which tools and view controls are selected.

Tool frame -- A tool box that has child tool boxes.

Tool settings -- Special settings that apply to certain tools, such as length and angle settings for the Place Line tool.

Tool settings window -- The window that contains controls for adjusting the selected tool's settings.

Top -- The orientation in which the positive X-axis points right and the positive Y-axis points up.

Touch screen -- monitor input where you can use your finger to draw on a screen or select an on --screen object. Touch screen technology is often used in ATM machines or in malls, for example, in electronic information kiosks/directories.

Trackball -- Operating like a mouse, a trackball remains stationary while a ball on its top is rolled with the fingers. Because you don't move it around the desk/mousepad like a mouse, it takes up less space.

Trigger -- An SQL procedure that loads a screen form with the correct information from the database when the user reviews attributes or loads displayable attributes.

TrueType Font (TTF) -- A font type definition used in Windows Window's built-in "outline" font technology. It works by taking a mathematical description of a font's outline and using it to "paint in" on-the-fly screen and printer representations. The printed appearance is true to the displayed appearance, hence "true-type". True-type fonts are stored in two files, with the extensions .TTF and .FOT.

U3D -- The universal 3D format introduced by the 3D Industry Forum as a means for transferring 3D data from CAD systems to mainstream applications such as marketing, training, sales, technical support and customer service.

UCS (User Coordinate System) -- A modified coordinate system set in AutoCAD drawing

Unit distance -- The setting that specifies the spacing between points that data points will be restricted to when Unit Lock is turned on.

Unit lock -- The setting that, when on, forces all graphically entered data points to the nearest point that is an integer multiple of the unit distance from the global origin in the X, Y, and (in 3D files) Z directions.

Unshared cell -- A cell whose definition is placed in the DGN file each time the cell is placed.

Update -- To redraw the contents of a view window(s).

URL (Uniform Resource Locator) -- The addressing scheme used to link resources on the Web. Like the post office, which must have addresses to deliver mail, Internet users and their computers, must have addresses in order to send and receive messages. A URL has two parts, separated by ://. Example: http://www.whitehouse.gov

USB (Universal Serial Bus) -- Serial interface that allows connection of up to 127 devices at speeds of either 1.5 or 12Mbits/s. It supplies power for those devices and allows the devices to be hotswaped (added and removed without rebooting). Currently used to connect keyboards, mice, printers and scanners.

User -- A type of configuration variable that determines which project configuration file is processed.

User configuration file -- The file that contains the active workspace components.

User interface -- A customized user interfaced (defined in Modification resource files in subdirectories under MicroStation's workspace user interface).

V7 workmode -- The MicroStationworkmode in which certain functionality is disabled by default in order to restrict MicroStation to creating only engineering data that can be stored in the MicroStation v7 (MicroStation/J) design file format.

VBA (Visual Basic for Applications) -- A custom application development tool (Visual Basic) embedded in many Windows programs like MS Office, AutoCAD, Inventor and others.

VDAFS Surface Interface -- VDAFS or VDA (Verband Deutscher Automobilhersteller) for short is an industry standard data format commonly used in the automotive industr for the transfer of surface information. It is especially suited to freeform surfaces that are often found in the exterior and interior surfaces and are produced using surface --based CAD applications. Additionally, the VDA format allows for the transfer of points, vectors and facetted data. VDAFS does not allow for solids based information. The format is defined in a DIN standard.

Verb-noun -- A manner of operating MicroStation: choosing a tool before identifying an element in the design for it to act upon.

Vertex -- The highest point or apex of a figure, the intersection of lines or curves, or the endpoint of an element.

VGA -- A video monitor/card supporting 640x480 resolution with 16 colors. (Also covers resolutions of 320x240 with 256 colors.)

Video RAM -- Special memory chips residing fast video cards. The more memory, the higher the resolution. For example, to put out 256 colors you need 512K of video RAM; for 16.7 million colors, you need 2 Mb. (See VRAM).

Video Scan Converters -- Convert computer RGB signals to NTSC, PAL or SECAM video signals. Once converted, these signals may be videotaped or shown on a television monitor.

Video, analog -- True full-motion video from laser discs, videotapes. Formats: Hi8, 8mm, S-VHS, VHS.

Video, component -- Used in Hi8 and SuperVHS cameras, component video splits the single composite video signal into colors (RGB) and improves the quality by adding a luminance or brightness (Y) channel and a color/chroma intensity (C) channel. Superior to composite video.

Video, composite -- Single-signal video, used in VHS. Inferior to component video.

Video, digital -- Digitized video, i.e. video converted/compressed to file format. Formats: .AVI (Video for Windows) and .MOV (QuickTime -- cross --platform for both Macintosh and Windows).

Videoconferencing -- Transporting real-time voice and video over telecommunications services. Nowadays, "Web conferencing" is the fashion, thanks to various desktop videoconferencing (DVC) products like Enhanced Cu-SeeMe.

View -- Collectively, the portion of the active model (and its attached references) and displayed in a view window and the display orientation.

View axis -- For element placement, the axis relative to the view.

View configuration -- The arrangement of view windows on the screen and the area of the model displayed in each view.

View control bar -- The bar at the bottom border of each view window from which commonly used view controls can be selected.

View controls -- Graphically operated controls that affect the portion of the design or the orientation of the information in a view.

View cube -- The portion of the design cube in a view.

View delta -- The extent, in working units, of a view along its horizontal and vertical axes.

View dependent settings -- Settings that affect the presentation of information in a view.

View group -- A set of view window layouts applicable to a model within the open DGN file. A view group is also a set of views placed on a sheet file in a sheet model.

View independent text -- A text element that displays at its angle of placement regardless of how the view is rotated.

View volume -- The volume displayed in a 3D view.

View window -- A window displaying a view.

Viewing pyramid -- A dynamic that shows you what will be included in a view with perspective projection.

Visible edge -- A form of rendering in which the edges of surfaces are made visible.

Visible edges DGN file -- DGN file created using edges hidden line removal.

Visible surface shading -- See surface shading.

Voice recognition -- Software which recognizes spoken commands. Most software has to be individually trained for each voice, making its general usage limited.

Void -- A fence selection mode that selects elements or parts of elements outside the fence, rather than within the fence.

Void-clip -- A fence mode in which only the elements that are completely outside the fence and those parts of elements outside or overlapping the fence are included in the fence contents.

Void-overlap -- A fence mode in which only the elements outside or overlapping the fence are included in the fence contents.

Volume of projection -- See solid of projection.

Volume of revolution -- See solid of revolution.

VRML (Virtual Reality Modeling Language) -- description language for 3D models, scenes and animations.

WAN -- Wide Area Network.

Wavetable -- sound synthesis using a built --in selection/table of actual recordings. The output is more realistic than that produced by the older technology, FM synthesis.

Whiteboard -- A teleconference function that lets multiple users simultaneously view and annotate electronic documents with pens, highlighters and drawing tools.

Window -- A bordered rectangular region on the screen displaying a tool box, dialog box, view, or sidebar menu.

Window control menu -- A menu opened by clicking the window menu button on the left end of a window's title bar.

Window origin -- The position in the design plane of the lower-left corner of a view.

Windowing -- A method of selecting new contents for a view.

Wireframe -- A display mode in which surfaces are displayed as their outlines, and elements behind surfaces are displayed as though the surfaces did not exist.

Wiremesh -- A rendered display similar to wireframe except that curved surfaces are represented by a polygonal mesh for increased realism.

Witness lines -- See extension lines.

Work line -- The line in a multi-line element connected to the pointer during placement.

Working set -- A temporary grouping of elements that need not be close together. Fence manipulation tools operate on working sets.

Working unit settings -- The settings that designate the working units and working resolution. In the current implementation, MicroStation uses IEEE 64–bit floating point storage, which allows for a high degree of accuracy and a working volume with each axis roughly 2 million times larger than the axes in V7.

Working units -- Real-world units that the design plane is configured to.

Workmode -- An operating mode of MicroStation such as DGN, DWG, and V7 workmodes.

Workspace -- A custom MicroStation environment or configuration.

WRL (virtual WoRLd) – A file in the VRML format.

XML - eXtensible Markup Language.

Xref -- eXternal REFerence -- externally referenced AutoCAD drawing -- e.g. with plumbing plan (layers) of an AEC project.

Zoom -- To decrease (zoom in) or increase (zoom out) the portion of the design displayed in a view.