The following geometrical objects in SPRAY may be covered by simple pre-defined interfaces or user-defined interfaces (details of interfaces have been given above). The objects are divided into two classes: Some (like spheres or solid cylinders) completely enclose a certain volume with their surface. These are called Closed volumes. Others (like rectangles or circles) are referred to as 'Open structures'. These objects cannot enclose a volume alone.

'Open' structures:

•Rectangle

•Triangle

•Circle

•Sphere segment

•Cylinder (open)

•Cone

•Ellipsoid segment

•Paraboloid

•Circular aperture

•User-defined surface: Rectangular basis

•User-defined surface: Circular basis

Closed volumes

•Sphere

•Cylinder (closed)

•Rectangular box

•Prism

•ATR crystal

•Converging lens

•Diverging lens