A Clump is a collection of Polygons and Vertices. Clump objects allow applications to handle large numbers of related polygons and vertices as a single, atomic entity. This greatly simplifies application construction.
Each polygon has an associated Material object, which defines the appearance of the polygon. Each material object may be shared by many polygons. Material objects encapsulate the following surface properties: geometry sampling type, light sampling type, RGB color; ambient, diffuse and specular coefficients of reflection, opacity, texture and texture modes.
A Light source illuminates objects in a scene. Three types of light source are supported:
A Camera captures an image of the objects in a 3D scene projected onto an image plane (or view plane). The projection may be either perspective or parallel. A rectangular region of this plane (called the view window) is stored as a 2D image in the cameras image buffer. The rectangular region of pixels on the output device onto which a cameras view window is mapped is the cameras viewport.
A Scene is a collection of clumps and lights. A scene may be viewed through one or more cameras. At any instant, however, only one camera is active (the current camera) and the results of rendering are stored in the image buffer of this camera.