How to import BREP to Parasolid, ACIS or OpenCascade


This is a very common use case, and HOOPS Exchange includes several tools that help with this. It’s also covered in our documentation and so a lot of what is written below is simple referencing into the HOOPS Exchange documentation.

Importing your models to Parasolid

If you are a Parasolid user then you can simply use our Parasolid integration to quickly and easily import your data. The HOOPS Exchange for Parasolid Developers section of our HOOPS Exchange documentation. We have worked closely with Siemens to ensure that when models are imported, they come in with high quality and can be operated on by the Parasolid APIs.

Importing your models to ACIS, OpenCascade or other modelers

There are two approaches that are covered here. The first is what we call indirect integration where you simply export your file as a format that is supported by your modeler (for example SAT with ACIS) and then simply import that model. The problem here is that some of the important information (e.g. assembly level structure, meta-data) may get lost. As a result, a lot of people end up doing a direct integration. In this case they traverse the model tree and query the model directly and import the information they need into their system. In a lot of case people stop once they reach the body level of the assembly tree and then simply export the body using one of our BREP exports (Parasolid, ACIS or STEP). The Simple Import and Export and Reading Geometry sections in the HOOPS Exchange documentation provide some good details, including sample code, on these two different types of integrations.

Adapting the BREP to work with your modeler

You want to make sure that when you import your model you can successfully perform modeling operations on the imported data. To do this, you often need to massage the imported geometry to ensure it is adapted to the needs of your modeler. For example, you may need to split periodic surfaces or approximate surfaces which do not have an analogous representation in your modeler (for example, blend surfaces often need special treatment to be imported). HOOPS Exchange provides a variety of functionality that allows you to massage the data after you import it and before you then bring it into your own modeler. You can find detailed information, including sample code, in the Converting the BREP to NURBS and Approximating Curves & Surfaces sections of the HOOPS Exchange documentation.