McCad - BRep to CSG

McCad是一个开源工具，能自动将BRep模型转换成CSG模型。随着核动力技术的发展，不断开展新型反应堆的研究，反应堆的燃料形式和堆芯布置都较为复杂，由于蒙特卡罗(MC)方法具有强大的几何处理能力和较高的计算精确度，它是模拟分析这些复杂堆芯的有效手段。通过使用McCad将复杂BRep模型转换成CSG模型，CSG表示的模型可作为核反应堆芯计算蒙特卡罗(MC)方法的输入。

McCad基于OpenCASCADE内核已经持续开发了20年，基于LGPL协议开源，感兴趣的小伙伴可以下载尝试一下：

https://github.com/inr-kit/McCAD-Library

BRep转CSG个人感觉没有完美的解决方案，但是应用范围很广。如果转换效果好，其实还有一个用途，就是将BRep转换的CSG模型导入到PDMS中，从而解决通过机械设备接口MEI导入STEP/IGES后PDMS模型数据变大的问题。

McCad is an open source tool for automatic conversion of B-Rep models into CSG.

McCad has been continuously developed for more than two decades. It provides automatic conversion of Boundary Representation (BREP) CAD models into Constructive Solid Geometry (CSG), the latter of which is an input syntax often used in Monte Carlo (MC) radiation transport codes. The conversion process, from BREP to CSG, is essential for high-fidelity nuclear analysis of complex nuclear facilities. McCad can convert CAD files in STEP format to different input syntaxes used with MC codes such as MCNP, TRIPOLI, Geant4, etc., so that the manual efforts on building a complex simulation model can be avoided. McCad provides an advanced algorithm to decompose complex solids into its constituent convex primitives, and generates the void space description between the solids, which is required by MC codes.

It relies on OpenCASCADE CAD kernel to perform CAD manipulations and Boolean operations. McCad has been integrated into the SALOME platform, with a detailed manual provided. It is an open-source code released under LGPL license. This code has been currently used for nuclear research institutes crossing continents, for nuclear analyses on fission reactors, fusion facilities and neutron source facilities.