Description:

OpenCSG is a library that does image-based CSG rendering using OpenGL.

CSG is short for Constructive Solid Geometry and denotes an approach to model
complex 3D-shapes using simpler ones. I.e., two shapes can be combined by
taking the union of them, by intersecting them, or by subtracting one shape
of the other. The most basic shapes, which are not result of such a CSG
operation, are called primitives. Primitives must be solid, i.e., they must
have a clearly defined interior and exterior. By construction, a CSG shape is
also solid then.

Image-based CSG rendering (also z-buffer CSG rendering) is a term that denotes
algorithms for rendering CSG shapes without an explicit calculation of the
geometric boundary of a CSG shape. Such algorithms use frame-buffer settings
of the graphics hardware, e.g., the depth and stencil buffer, to compose CSG
shapes. OpenCSG implements a variety of those algorithms, namely the
Goldfeather algorithm and the SCS algorithm, both of them in several variants.