Computer-aided design
As in the manual drafting of technical and engineering drawings, the output of CAD must convey information, such as materials, processes, dimensions, and tolerances, according to application-specific conventions.
CAD is also widely used to produce computer animation for special effects in movies, advertising and technical manuals, often called DCC digital content creation.
The modern ubiquity and power of computers means that even perfume bottles and shampoo dispensers are designed using techniques unheard of by engineers of the 1960s.
Virtually all of CAD tools rely on constraint concepts that are used to define geometric or non-geometric elements of a model.
Basic three-dimensional geometric forms (e.g., prisms, cylinders, spheres, or rectangles) have solid volumes added or subtracted from them as if assembling or cutting real-world objects.
There are several types of 3D solid modeling Top-end CAD systems offer the capability to incorporate more organic, aesthetic and ergonomic features into the designs.
Freeform surface modeling is often combined with solids to allow the designer to create products that fit the human form and visual requirements as well as they interface with the machine.
Originally software for CAD systems was developed with computer languages such as Fortran, ALGOL but with the advancement of object-oriented programming methods this has radically changed.
Typical modern parametric feature-based modeler and freeform surface systems are built around a number of key C modules with their own APIs.
A CAD system can be seen as built up from the interaction of a graphical user interface (GUI) with NURBS geometry or boundary representation (B-rep) data via a geometric modeling kernel.
Current computer-aided design software packages range from 2D vector-based drafting systems to 3D solid and surface modelers.
Furthermore, many CAD applications now offer advanced rendering and animation capabilities so engineers can better visualize their product designs.
4D BIM is a type of virtual construction engineering simulation incorporating time or schedule-related information for project management.
Most applications support solid modeling with boundary representation (B-Rep) and NURBS geometry, and enable the same to be published in a variety of formats.
