This page describes the svLis set-theoretic (or CSG) geometric modeller, which is coded in C++. SvLis was written at the University of Bath, where research has been done in geometric modelling for many years.

The design philosophy of svLis is simple. It is an efficient set-theoretic geometric modeller which is straightforward enough for any technical person who knows a little C++ to get to grips with in a day or two, but which is sufficiently rich in operations and entities to be able to represent a very wide range of shapes for all aspects of engineering, for many aspects of science, and possibly some for art as well. It is user-extendible in lots of ways, and provides safe function calls to give access to all its internal geometric structures. It is intended to be easy and intuitive to program with, allowing operations to be performed using overloaded operators and functions in the usual object-oriented way, but using sophisticated memory-management strategies to allow the sharing of common data and the efficient passing of results in a completely transparent manner.