While specific rendering techniques are explored in the following
section, many of these algorithms rely on two fundamental signal
processing tools—smoothing and derivative estimation—as well
as on the ability to effectively segment objects. Therefore, we begin
by describing a toolbox of methods analogous to those available in
image processing and digital geometry processing. These tools tend
to offer the power and control of geometry-based methods, while
retaining the simplicity and efficiency of image-based methods