Modeling of a three-dimensional object includes storing data representing
a computer model of the three-dimensional object. The data includes a
number of feature objects each of which defines a feature of the computer
model. A feature chain is formed and includes at least one feature object
having a design effect limited in scope such that an operation for
removing material operates to affect the feature of the computer model
defined by another feature object in the same feature chain and does not
affect the feature of the computer model defined by the feature object
not in said same feature chain. Multiple feature chains can be combined
to form an interrelationship among feature objects that represents a
hierarchy defining construction of the model from the feature objects.