ACIS
ACIS is an object-oriented three-dimensional geometry kernel programmed in C++ in CAD applications. ACIS is a made-up word for the first names of the developers Alan, Charles and Ian and for Spatial Corporation, which developed the kernel in 1986 and has belonged to Dassault Systèmes since the end of 2000.
ACIS is a B-Rep or surface boundary modeler and is responsible for designing computer-aided engineering and manufacturing solutions such as CAD systems, computer-aided engineering( CAE) or CAM systems, and for mapping engineering processes for product lifecycle management( PLM). The ACIS core is part of a CAD system and has 3D functions for wireframe models, surface models and solid models for parametric, hierarchical and associative modeling and documentation.
Since 1990, ACIS has established itself as an industry standard, reaching an installed base of over 440 licenses worldwide by 1998. More than 170 third-party CAD applications have been populated with the modeler. Equipping each CAD solution with its own geometry kernel would have involved considerable development effort and costs, which not all manufacturers were prepared to incur. Instead, they used appropriate program libraries that provided CAD modeling functions. Currently, there are two commercial modeling kernels that are licensed to several CAD manufacturers and used in different CAD systems: ACIS with the file extension is *.sat and Parasolid from Shape Data, which is further developed today in a division of Siemens PLM Software and has the file extensions *.x_t or *.x_b. Both cores are implemented with open system architecture in C++.
Other modelers are directly included in the solutions of their manufacturers, including PTC (with Pro/Engineer software), Dassault (with CATIA), ASCON (C3D in KOMPAS 3D) or DAKO (with WorldCAT). The ShapeManager used by Autodesk is also based on the ACIS core and was further developed from it. Freely available, on the other hand, is the Open-CASCADE core. The software tool serves as a development basis for 3D application programs for CAD, CAM and CAE. It is similar to an LGPL license (Lesser General Public License) and can be run under Windows, Linux and Solaris.