|The XDE (Extended Data Exchange) module is an optional kit available for users of certified version of Open CASCADE on all platforms supported by it (Linux, Sun Solaris, Windows).|
|The basis of XDE, called XCAF, is a framework based on OCAF (Open CASCADE Application Framework) intended to work with assemblies and with various kinds of data (attributes) attached to shapes. The following types of data are supported currently: |
- validation properties
The support of these data is described below. It is also possible to add a new types of data taking the existing tools as prototypes.
Finally, the XDE provides reader and writer tools for reading and writing the data supported by XCAF to and from IGES and STEP files. Some examples of IGES and STEP files with colors and other attributes read to XDE are given in the following paragraphs
XDE supports assemblies by separation the shape definition and its location. The shape itself is stored in OCAF as a simple shape object without location, and then asseblies are defined by specifying what shapes they have as components, and with what locations. This gives a flexibility to define and easily work with complex multi-level assemblies.
Validation properties are quite a new feature of STEP standard, currently being actively tested by CAX-IF organisation and implemented in commercial STEP translators.
Validation properties are geometric characteristics of shapes (volume, centroid, surface area) which can be put to the STEP file by the sending system. These data should be used by the receiving system in order to validate quality of translation (by comparing these values computed by original system with the same values computed by receiving system on resulting model).
Advanced Data Exchange supports both reading and writing validation properties, and provides some tool to check them.
XDE supports reading and writing names of shapes to and from both IGES and STEP formats. This functionality can be switched off in case of need (if these data are not needed, thus avoiding unnecessary information in the document).
Colors and Layers
XDE can read and write colors and layers assigned to shapes or their subparts (down to level of faces and edges) to and from both IGES and STEP formats.