PROGRAMMING GUIDE
HOOPS Exchange lets you create a representation item for a boundary representation that is optionally accompanied by tessellation data. Boundary representations with or without tessellation data can represent curves, or open or closed solids. (For information on providing tessellation data please review Creating a tessellation entity for representing faceted objects.)
For developers who are have the ability to export ACIS, IGES, Parasolid or STEP data from their application the recommended approach for creating a boundary representation model is to build up the assembly tree via the Exchange APIs and then for each part in the assembly provide the definition in an ACIS, IGES, Parasolid or SAT file. This will avoid the need for developers to work at a very low level to define their boundary representation model and should be a fairly straight-forward implementation. There is some minor pre-processing of the ACIS data that developers need to do prior to providing the data to HOOPS Exchange. For directions on this please contact the HOOPS Developer Support team.
This section explains how to create a PRC file that represents a circular band (a co-edge) that is UV-mapped to a clear cylinder surface (pictured below). More specifically, the solid in this 3D image contains a single face, which in turn contains a cylinder and a loop. The loop contains a single co-edge that contains two circular curves. The co-edge is UV-mapped to the cylinder. The following images show the resulting image from different perspectives. To open a PDF document that contains the PRC content pictured below, click here.
The following diagram shows the tasks required to create each PRC entity to represent the image pictured above. This diagram is intended to portray a bottom-up process, where upper-level functions are not complete until their lower-level functions are completed. That is, the most basic PRC entities (such as vertices, edges and coedges) are created first, followed by the more complex PRC entities that consist of those basic PRC entities and other data. The last PRC entity to be created is the model file.