Neutral Formats

Supported Neutral Input Formats

All of the above formats support single or multiple region definitions in a single file. When importing multiple files as regions, the choice of generating either a single region per file or multiple regions is provided. When importing as parts, the original hierarchy of the parts is maintained. You can choose to create a single part surface per part if you wish. For more information on the various import options, see Importing Surface Data into Simcenter STAR-CCM+.

None of the neutral file formats support part curves (line cells). Part curves can be automatically created based on an angle (sharp edges) or all feature edges during the import process if desired.

IGES Format

Initial Graphics Exchange Specification (IGES) is a neutral data format that allows the exchange of digital information among CAD systems. It can contain models in the form of solid models as well as other types of product data. Although it has been around for almost 30 years, and has been superseded by other formats such as STEP, it is still the most widely used standard for translating CAD data.

The demarcation of parts and surfaces is determined automatically based on the bodies and patches that are contained in the file. Surfaces that are imported from IGES files are always represented as CAD parts initially.

No units specification option is provided as this information is automatically preserved by the file.

STEP Format

Standard for the Exchange of Product model data (STEP) is an international standard for the exchange of industrial product data. It was developed to provide a method for describing product data through its life cycle but is typically used to exchange data between various CAD, CAM, and CAE applications.

Surfaces that are imported from STEP files are always represented as CAD parts initially. No units specification option is provided as this information is automatically preserved by the file.

VDA Format

Verband der Automobilindustrie (VDA) originated from the German automobile industry. VDA is a CAD data exchange format that allows surface data to be transferred from one CAD program to another. VDA is also called VDA-FS in some CAD programs.

No units specification option is provided as this information is automatically preserved by the file. Surfaces that are imported from VDA files are always represented as CAD parts initially.

Unclosed surfaces in the original .vda file remain unclosed when imported into Simcenter STAR-CCM+. Use the surface wrapper to obtain a closed surface suitable for volume meshing.

Parasolid Transmit Format

Parasolid is a geometric modeling kernel that is owned by Siemens PLM. It is used as the basis of many CAD, CAM, and CAE packages for modeling three-dimensional solid objects. Parasolid Transmit files can be binary (.x_b) or ASCII (.x_t) - the selection of the file format type is made during the export process.

No units specification option is provided as this information is automatically preserved by the file. CAD data imported from Parasolid Transmit files are represented as 3D-CAD parts () while faceted data are imported as surface mesh parts (). Parasolid Transmit files that contain a mixture of CAD and faceted geometry can also be imported into geomerty parts or 3D-CAD. Any CAD body with mixed geometry data is imported into geometry parts as a mesh part or into 3D-CAD as a faceted body.

To allow precision to be handled correctly, all parts of the Parasolid body must fit in a box no larger than 1000 x 1000 x 1000 units and is centered at the origin. For example, if the default units in the CAD application are set to meters, the maximum distance in any one direction that can be modeled is 1 km.

ACIS Format

The ACIS Modeler is a geometric modelling kernel from Spatial Corporation, which is a part of Dassault Systemes.