Glossary of Computer Related Terms

Computer Aided Design (CAD):  The use of computer technology (including various software) for creation and modification of designs. Almost all 3D printers rely on CAD for creation and editing of virtual objects that are later printed.

Computer Aided Manufacturing (CAM): The use of computer software to control machine parts for manufacturing objects. 3D printing is a type of CAM in which various software are used to give instructions to a 3D printer to print a desired object.

Computer Numerical Control (CNC): Machines which allow digital tools to be crafted automatically without being controlled by an operator.

Concept Model: A physical model of a final product which demonstrates its form but which may lack details, texture and functionality.

Firmware: The software that runs on the electronics and controls the 3d printer.

G-Code: The format of information which some 3D printers use to control them and which is sent from a computer to the printer.

Iteration: The repetition of a process. Used in reference to a generation, version, or edition of a 3D printer model.

Mesh: The surface of a 3D object when defined as a computer model. Typically, a curved shape will be redefined as a series of flat triangles. The smaller the triangles, the finer the printed result.

Model Repositories: Digital libraries or storage places for 3D model files

Object File (OBJ): A geometry definition file format from 3D modeling programs commonly used in 3D printing. It is an alternative to the STL file format. OBJ was developed by Wavefront Technologies in the early 1990s. Most 3D software is able to export OBJ files, and some 3D printing programs (such as Netfabb and Meshlab) can read objects created in this format. 

Open Source: Open Source refers to a collaborative nature of development. Open source software for example has free, public code which can be downloaded, modified and redistributed by multiple developers. With regards to 3D printing there is a wide variety of open source software that you can use to make and modify 3D models.

Open Source History: Open source software as we know it began with the launch of the free software movement in 1983. With the publication of the GNU manifesto and the launch of the GNU project, the goal was to develop a computer operating system that was free from constraints on its source code. Soon to follow was Linux in 1991. The label “open source” came sometime later after Netscape released the source code for Navigator internet browser in 1998. The vast majority of programming languages have been open source since the 1990’s, including Python and Ruby. The trend continues to today, with notable open-source Android smartphone operating system and the hugely popular software version control system called Git. The most notable open source project in 3D printing history is the RepRap project. RepRap is the first general-purpose self-replicating manufacturing machine. As an open source project, anyone in the RepRap community can edit and contribute to the development of the project, while all designs and software are free to use. The RepRap website provides an extensive list of open-source and free-to-use software for CAD modeling and STL handling. The major advantage of open-source technology is that it’s free to use and typically has a strong community base around it.

Parametric: Adjustable in all dimensions. A parametric model is one that can be resized and or distorted to suit the user’s needs. In CAD software, if a widget has a 1 cm hole in it, you can select that hole and make it a 5 mm hole with a few clicks, as opposed to a triangular mesh, which is more difficult to adjust. The native format of several useful software packages can store parametric models.

Prototype: A draft model used to present or test a design.

Rapid Prototyping (RP): Any process which uses computer controlled machinery to create a prototype of an object.

Slicer: A slicer is a software required to convert a digital 3D model into machine readable code for the 3D printer. The slicer cuts the model into horizontal layers (slices) and generates the toolpaths needed to fill them.

Slicing: The process by which a 3D model (usually in STL format) is turned into a G-code file that can then be interpreted by a 3D printer. Slicing involves defining the object as a sequential series of layers, printed from the bottom up. The thinner the layers, the finer the resulting print.

Stereolithographic or Standard Tessellation Language (STL): CAD software originally developed by 3D Systems in 1987 and still used by most 3D printers today. STL is a file format used to describe 3D models. It differs from formats such as OBJ in that it specifies the surface of the model only, but not the color or texture. STL is the most common format used when exchanging and publishing 3D models suitable for printing. All CAD applications can export STL files, but design programs such as Photoshop and Poser cannot. Instead they export OBJ files that need to be converted to STL format.

Vector Graphics and/or 3D Computer Graphics: A vector graphic is a type of image. Vector images are graphical representations of mathematical objects such as lines, curves, polygons and its like. These graphics are generated by computer and follow x and y axis as their reference definition. Is also referred to as 2D. 3D computer graphics follow x , y, and z axie as their reference definition. One characteristic of vector graphics is a very high resolution. Such images can be altered easily and their resolution per square pixel remains intact at any level. Common image formats like GIFs and JPEGs are the opposite — these bitmap images are pixel-based and so cannot be resized without losing quality. Once a vector image is rasterized to a .gif or .jpeg, they lose their original resolution.

X3G: A file format read by some 3D printers to print design files.