GRAPHICS PIPELINE MODEL

The model requires the user to first define the geometric models which are then rendered via a sequence of pipeline stages:

subject these models to several 3D transformations,
followed by clipping, then
projection to the plane,
followed by planar transformations,
and finally converting these to pixels.

The stages can be affected various state variables.
-- The user can read and modify the state variables.

PROS and CONS OF STATE MACHINES:
-- E.g., we say "create this vertex", and let the default COLOR, SHADING, TRANSFORMATION, etc be applicable to this current vertex.
-- Harder to understand a command locally.