CAD files embed two kind of data for the 3D bodies: BRep and Tessellation.
A BRep body is described by mathematical parameters and a topology. In order to display a BRep body, HOOPS Exchange evaluate the parameters and generate a tessellation. The BRep parameters are accessible in the PRC.
A Tessellated body, is simply a list of vertices organized in faces.
Depending on the format, the PRC you get from a HOOPS Exchange conversion may contains BRep, Tessellation or both.
The tessellation may be generated by HOOPS Exchange or extracted from the CAD data. More info
After the convertion of a model to PRC, you can identify which entities are B-Rep and which are tessellated bodies.
- Traverse the tree to the Representation Item level
- Check the Representation Item type
- A3DRiPolyBrep: this is a tessellated body. In HOOPS Demo Viewer it is described as “Faceted solid”
- A3DRiBrepModel: this is a B-Rep body, you can parse its parameters and explore its topology.
- A3DRiSet: this a collection of A3DRiRepresentationItem. You need to check the type of the children of this entity.