Scene statements are used to build up a hierarchical representation of the environment. A static SLIDE file is comprised of a sequence of one or more of the SLIDE statements described in the following sections to describe both the objects and viewing parameters in the scene.
The fundamental geometric object supported in SLIDE is a polyhedron -- a solid object bounded by polygonal faces. In SLIDE, a polyhedron is described using a boundary representation (B-REP) by defining the individual polygonal faces that bound an object. Each polygonal face is described as an ordered list of vertices, the perimeter of the face being constructed by connecting these vertices in order. In SLIDE, vertices, polygonal faces, and the polyhedra that they bound are defined by the point, face, and object statements.