Cobalt is a parametric-based computer-aided design (CAD) and 3D modeling program that runs on both Macintosh and Microsoft Windows operating systems. The program combines the direct-modeling way to create and edit objects (exemplified by programs such as SpaceClaim) and the highly structured, history-driven parametric way exemplified by programs like Pro/ENGINEER.

Cobalt integrates wireframe, freeform surfacing, feature-based solid modeling, photo-realistic rendering (see Ray tracing), and animation. Cobalt, a product ofAshlar-Vellum, is history-driven with associativity and 2D equation-driven parametrics and constraints. It offers surfacing tools, mold design tools, detailing, and engineering features. Cobalt includes a library of 149,000 mechanical parts.^[1]

Cobalt’s interface, which the company named the “Vellum interface” after its eponymous flagship product, was designed in 1988 by Dr. Martin Newell ^{[Note 1]} and Dan Fitzpatrick. The central feature of the Vellum interface is its “Drafting Assistant”, which facilitates the creation and alignment of new geometry.