Method of representation:

CSG methods are useful both like a method of representation and as a user interface technique. A user may be supplied with a set of primitive solids and may combine them interactively by using the boolean set operators to generates more complex objects. Editing a CSG representation is also simple, for instance changing the diameter of the hole in the instance above is only a case of changing the diameter of the cylinder.

Though, it is slow to generate a rendered image of a model from a CSG tree. It is because most rendering pipelines work on B-reps and the CSG representation ought to be converted to this form before rendering. Therefore some solid modeller use a B-rep but the user interface is depends on the CSG representation.

An object is stored up as a tree along operators at the internal nodes and simple primitives at the leaves.