What is CGM ?
The Common Geometry Module (CGM) is a code library which provides geometry functionality used for mesh generation and other applications. This functionality includes that commonly found in solid modeling engines, like geometry creation, query and modification; CGMA also includes capabilities not commonly found in solid modeling engines, like geometry decomposition tools and support for shared material interfaces. CGMA is built upon either ACIS or OpenCascade (OCC) solid modeling engine, but also includes some geometry capability developed natively. CGMA can be used as-is to provide geometry functionality for codes needing this capability. However, CGMA can also be extended using derived classes in C++, allowing the geometric model to serve as the basis for other applications, for example mesh generation. CGMA is supported on various computing platforms, including parallel computers.
CGMA is derived from the Common Geometry Module (CGM) developed at Sandia National Laboratories. CGMA was forked from CGM shortly after the release of CGM 10.2. Depending on whether Sandia continues to release CGM along with new releases of CUBIT, CGMA may or may not stay current with CGM. Features will be added to CGMA which likely won’t make their way back into CGM, again depending on what Sandia decides to do. CGM serves as a basis for the CUBIT code, and can be obtained in source code form here.
CGMA should be able to read and restore geometry created in CGM and CUBIT. CGMA is maintained in a world-readable bitbucket repository https://bitbucket.org/fathomteam/cgm. If you would like to participate in the development of CGMA, contact Vijay Mahadevan or Jane Hu for getting write access to the CGM repository.
CGMA and ACIS
CGMA can be compiled with or without the ACIS modeling engine. In addition, the decision about whether to enable ACIS in CGMA can be made by the application at compile time, or even at run time if the appropriate share library magic happens. In its most widely used configuration, though, CGMA usually incorporates ACIS. To build CGMA, therefore, one usually needs the ACIS libraries and the CGMA code which calls ACIS.
Because of license restrictions on code calling ACIS functions, we are not allowed to release the CGMA-ACIS code under an open source license. If you would like this code, you must contact the CUBIT project at Sandia National Laboratories (cubit-dev _at_ software.sandia.gov) and request the code, and be prepared to prove you have an ACIS license.
CGMA and Cubit
CGMA can be configured with the CUBIT code from Sandia National Laboratories. To accomplish this, pass the –with-cubit=$CUBIT_DIR option to the CGMA configure script, pointing it to the directory containing the CUBIT bin/ and lib/ subdirectories.
NOTE: Our current master code branch is working with Cubit 14.0. To obtain a license for the CUBIT code, see the CUBIT licensing web page.
The port to the Open.Cascade open-source modeling engine is ready for friendly testing. See the README file for build instructions and a list of functionality currently supported. Query and modify capabilities are available, with the latter an incomplete set but growing towards completion. Send any questions or problems to the cgma-dev email list (see below).
CGM version 12.2.0: CGM version 12.2.0 was released in March 2012; see the download link below.
CGM version 13.1.1: CGM version 13.1.1 was released in December 2013; see the download link below.
If you use CGMA, please be kind enough to send us a note about how you’re using it, to cgma-dev _at_ mcs.anl.gov. Feel free to send any bug reports and suggested improvements there too!