The capabilities of modern CAD systems include:
- Wireframe geometry creation
- 3D parametric feature based modelling, Solid modelling
- Freeform surface modelling
- Automated design of assemblies, which are collections of parts and/or other assemblies
- create Engineering drawings from the solid models
- Reuse of design components
- Ease of modification of designs of model and the production of multiple versions
- Automatic generation of standard components of the design
- Validation/verification of designs against specifications and design rules
- Simulation of designs without building a physical prototype
- Output of engineering documentation, such as manufacturing drawings, and Bills of Materials to reflect the BOM required to build the product
- Import/Export routines to exchange data with other software packages
- Output of design data directly to manufacturing facilities
- Output directly to a Rapid Prototyping or Rapid Manufacture Machine for industrial prototypes
- maintain libraries of parts and assemblies
- calculate mass properties of parts and assemblies
- aid visualization with shading, rotating, hidden line removal, etc...
- Bi-directional parametric associatively (modification of any feature is reflected in all information relying on that feature; drawings, mass properties, assemblies, etc... and counter wise)
- kinematics, interference and clearance checking of assemblies
- sheet metal
- hose/cable routing
- electrical component packaging
- inclusion of programming code in a model to control and relate desired attributes of the model
- Programmable design studies and optimization
- Sophisticated visual analysis routines, for draft, curvature, curvature continuity...
Originally software for CAD systems were developed with computer language such as Fortran, but with the advancement of Object-oriented programming methods this has over the last decade or so radically changed. The development of a typical modern Parametric feature based modeler and freeform surface systems are built around a number of key, C programming language, modules with their own APIs. A CAD system can be seen as built up from the interaction a GUI with an Associative engine and Geometry constraint engine controlling BREP, CSG and NURBS geometry via a Geometric modeling kernel.
Hardware and OS technologies
Today most CAD computer workstations are Windows based PCs; some CAD systems also run on hardware running with one of the Unix operating systems and a few with Linux. Generally no special hardware is required with the exception of a high end OpenGL based Graphics card; however for complex product design machines with high speed (and possibly multiple) CPUs and large amount of RAM are recommended. The human-machine interface is generally via a computer mouse but can also be via a pen and digitizing graphics tablet. Manipulation of the view of the model on the screen is also sometimes done with the use of a spacemouse/spaceball. Some systems also support stereoscopic glasses for viewing the 3D model.
CAD has to be seen as part of the whole Digital Product Development (DPD) activity within the PLM process and as such is used together with other tools, which are either integrated modules or stand-alone products. These include
- Computer-aided engineering (CAE) and FEA
- Computer-aided manufacturing (CAM) for automated programming of CNC machines
- photo realistic rendering
- raster to vector
- management of controlled documents and revision levels using Product Data Management (PDM)
Other related topics
Learn more about CAD.