3D CAD Glossary D - F

Data
Information used a basis for reasoning or calculation.

Database
Related information organized and stored so that it can easily be retrieved and, typically, used by multiple applications. A non-computer form of a database is the telephone directory.

Datum Planes
(See Datums)

Datums
A datum plane or planar face used to establish a plane of reference. When you create a sketch, it is inserted onto a datum. The origin of the datum becomes the x,y origin of the sketch plane. Datums are also referred to as Datum Planes, Reference Planes and Frames.

Default
A parameter or variable that remains in effect until changed. It is what a computer program assumes in the absence of specific used instructions. In most applications, the last known user value becomes the new default.

Digitize
Entering graphical location points into a computer with a tablet, puck, stylus, or scanner.

Digitizing Tablet
A graphics input device that generates coordinate data. It is used in conjunction with a puck or stylus.

Dragging
Dynamically moving the virtual image of a graphical entity across the display screen to a new location using a puck, mouse, or stylus.

DXF
An acronym for Drawing Interchange File. DXF is a file format developed by Autodesk, Inc. to produce an ASCII description of an AutoCAD® 2D or 3D drawing file. DXF today has become one of many neutral data formats such as IGES and STEP that can be opened or saved by many CAD systems. An acronym for Drawing Interchange File.

Endpoint
The exact location on a line or curve where it terminates.

Enter Key
Also sometimes called the "Return Key." It signals the computer to execute a command or terminate a line of text. In many 3D modeling systems today, the middle mouse button can also be used to perform the same function.

Extrude
A base, boss, or cut feature created by extruding an open or closed profile in a linear direction. Options may include the ability to scale, rotate, or offset the profile along the extruded distance.

FEA
Acronym for Finite Element Analysis. Process of converting a 2D or 3D model topology into a finite number of structural elements, applying case loads and boundary conditions, and then processing and displaying the results.

Feature-Based Modeling
A 3D modeling technique in which a part is designed by applying features that are similar to how the part is manufactured (e.g., holes, ribs, fillets, cuts, and bosses). Virtually all 3D modeling systems today are feature-based.

FEM
Acronym for Finite Element Mesh. A collection of finite elements that models a 2D or 3D structure. For each finite element, the mesh identifies the nodes that it connects to, its element type (linear solid, etc.), its material properties, and its physical properties, such as thickness.

Fillet Blend
A feature that blends multiple fillet radii that converge at a single point.

Flavoring
The process of tailoring a neutral format data file such as IGES to a specific CAD system.

Frame Buffer
A portion of a computer's memory that stores an image so that it can be displayed on the computer screen. The number of bit-planes in a frame buffer determines the total number of colors that can be displayed on the screen simultaneously.

Frames
(See Datums)

Free Form Geometry
Geometry that uses curves and surfaces to define objects.

Function Key
A key on the keyboard that can be assigned to perform a task. A function key is typically used as a shortcut to a lengthy string of keystrokes. There are 12 function keys (F1-F12) on a standard 101 key keyboard.