Glossary

This page is a glossary of common FreeCAD terms and definitions.

Jump to letter:

A
Arc:

Arch:

Assembly:

Axis:

B
Backtrace:

Bezier Curve:

Blueprint:

Body:

Boolean Logic:

Boolean Operation:

Boolean OPerations check:

BOPcheck:

brep:

B-rep:

B-spline:

C
Callout:

Chamfer:

Clipping Plane: The clipping plane is used to cut away at the model in the 3D view. It is just a visual aid and does not actually cut the model. Clone:

Coin:

COLLADA:

Command:

Compound:

CompSolid:

Constraint: A restriction on the geometric relationship between primitives in a Sketch. If a constraint has a numerical value, it is referred to as Datum (e.g., a distance constraint has a numerical value - the length of an imaginary line connecting the two points). A constraint that has no numerical value (e.g., a Horizontal constraint) is sometimes referred to as Geometric Constraint. Constructive Solid Geometry:

Coordinate:

Coplanar:

CSG:

Cut:

D
DAG: Degrees Of Freedom: (abbreviated as "DOF")

Dependency Graph: . Difference:

Directed Acyclic Graph: (abbreviated as "DAG")

Draft:

Drawing:

E
Edge:

Element: An item of Sketcher geometry such as a point, a line segment, an arc, a circle, etc. Extrude: A general term for extending a 2D object into 3D along 1 direction. See also Pad.

F
Face: A 2 dimensional topological construct. For example, a cube has 6 Faces. A face can be curved, like in case of a sphere, which has one face in FreeCAD. The CAD kernel defines it as: Part of a surface bounded by a closed wire(s). . Facet:

FC:

FCStd:

Feature: A step in a 3d part's evolution in the Part Design Workbench workflow. Examples are Pad, Pocket, Groove, Fillet, etc. As we create a model in the Part Design Workbench, each feature takes the shape of the last one and adds or removes something. Hence a "Pocket" feature is not only the pocketed hole itself, but the whole part with the pocket feature. FEM:

Fillet:

Fork:

Forked Model:

Frenet:

Freetype:

Frustum:

Fully Constrained:

Fuse:

G
GDB or gdb:

Geometric modeling kernel:

Git:

Group:

GUI:

H
Half_Space:

I
IGES:

Intersection:

J
JT:

K
Kernel:

KML:

L
Label:

Line:

Line Segment:

Lock:

Loft:

M
Macro:

Manifold:

Mantis:

Mesh:

Model:

MultiTransform:

N
Name:

Non-manifold:

Null Shape:

O
OCC:

OCE:

OCCT: Open CASCADE Technology. See OCC. Open CASCADE: The geometric modeling kernel (software library) underlying FreeCAD. Also called OCC or OCCT (for Open CASCADE Technology). See also OCE. OpenSCAD:

Origin:

Orthographic:

P
Pad: An extension of a Sketch in a direction perpendicular to the plane of the Sketch. See also Extrude. Part: A FreeCAD Workbench primarily used for a Constructive Solid Geometry workflow. A unibody solid. The lowest level component in an assembly. A container which groups any type of FreeCAD object and has a placement. (Introduced in FreeCAD V0.17.) PartDesignNext:

PD:

PDN:

Perspective:

Pivy:

Placement:

Planar:

Plane: A flat, two-dimensional surface that extends infinitely far. A primitive two-dimensional object created in the Part workbench. Plot:

Pocket: A feature that removes material from a solid based on a Sketch. Point: An item used to reference a single area in the 3D workspace. A “point” is dimensionless. It has a dimension on the screen, usually represented by a “dot” only so we can see where it is. See also Vertex. Polygon mesh:

Polyline:

POV-Ray:

PPA:

Primitive:

PySide:

Python:

Q
Qt: A cross-platform application and user interface framework. Also Qt4.

R
Raytracing:

Revolve:

Robot:

Rotate:

S
Section:

Self Intersection:

Shape:

Shell:

Sketch: A constrained 2D depiction of an object fixed to a plane or a Face. In FreeCAD a Sketch is always a 2-dimensional object somewhere in the 3D space. Sketcher: A workbench used to create 2D geometry by use of elements and constraints. Sketcher Solver:

Smooth Line:

Solid:

Solver:

Stable: A nickname for the last general release version of the FreeCAD software. This is typically the version available from sources other than the FreeCAD project. Compare with Unstable. STL: STereoLithography, also known as Standard Tessellation Language. A mesh file format defining only the surface of a 3D object. File extensions is *.stl STEP:

SVG: Scalable Vector Graphics. A vector graphics file format. Sweep:

T
Task panel:

Tasks tab:

Tessellation:

Thickness:

A Part Workbench tool to hollow out a solid and leave a defined uniform thickness. Toggle:

Topological Naming: A scheme whereby an edge or face, once created, is assigned a permanent name. Internally, FreeCAD identifies edges and faces on a solid by numbering them such as: Edge1, Edge2, Face1, Face2, etc. The problem is that these IDs are somewhat randomly applied, and they will change after something is done to the model that changes the amount of edges and faces. For example, if the model is revised an item linked to a Face2 could later erroneously become linked to a different face (which was renamed to become the new Face2), causing the user unwanted results. As of the FreeCAD 0.16 release Topological Naming has not yet been implemented, and so if an object is modified such that the number of edges or faces changes, the names of the edges or faces of that object might change too. Torus: A primitive shape. Tracker:

U
Union:

Unstable: A nickname for a very recent version of the FreeCAD software. This version will contain many changes recently implemented by the developers. It does not typically fail or produce wrong results, but it has not completed testing. Upgrade:

V
Vector:

Vertex:

W
WB:

Wire: A sequence of connected edges by vertices. The term wire is used in this sense mainly by Open Cascade Technology []and therefore also inside of FreeCAD. A Draft workbench command that creates a parametric wire. Workbench:

X
X: Commonly refers to the X axis.

Y
Y: Commonly refers to the Y axis.

Z
Z: Commonly refers to the Z axis.