2009

Table Of Contents
The scene contains a model of a mechanical arm and a cargo box to be
moved by the arm. The components of the mechanical arm include:
A cargo magnet cup on the end
Three arm segments
A base for the arm to swivel about
A four-legged base for the assembly
To work with this model using IK you must create a hierarchy for it.
Understanding hierarchies
Inverse Kinematics relies on hierarchical relationships between the components
of a model and the IK system to pose and animate the components. Before
using Inverse Kinematics it is important to understand hierarchies in Maya.
A hierarchy is composed of a series of nodes that are combined for some
purposeful relationship. Individual nodes may represent the surfaces of a
model, a network of textures that describe a shading material, or series of
joints in a skeleton. Hierarchies are structured in a top-down manner, with
one node at the top (the parent node or root node) and other nodes (child nodes
or leaf nodes) attached and interconnected beneath the top node.
264 | Chapter 6 Animation