Skandha4's capabilities are built on top of the object-oriented capabilities of xlisp. From the xlisp programmer's point of view, the most important new classes supplied by Skandha4 are
Class MATRIX44: Tranforms to position things in space. Class BIT-ARRAY: Arrays of bits. Per-polygon in/visible flags etc. Class INT32-ARRAY: Arrays of 32-bit integers. Index other arrays, etc. Class FLOAT-ARRAY: Arrays of 32-bit floats. Coordinates in space, etc. Class GRAPHIC-RELATION: A collection of named arrays, all same shape. Class LIGHT: Defines a light source in space. Class LIGHTING-MODEL: Define global lighting model. Class MATERIAL: Define a material type to make things out of. Class CAMERA: Defines an eye position in space.
Generating images in Skandha4 is done basically be generating an appropriate set of objects of the above classes, either by explicitly constructing them or by loading them from a file, and then sending a :DRAW message to the camera(s) you wish to 'look' through.