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92 5. Describing and Storing the VR World
5.1.2 Hierarchical Data Structures
Partitioning a polygonal model into sub-units that are linked in a parent-
child-grandchild relationship is useful. F or example, hierarchical linkages are
very significant in character animation, robotics and chain linkages. This
merges in well with simulations that involve kinematic and inverse
kinematic (IK) systems where force feedback plays an important part. An
easily implemented and practically useful scheme is one that is analogous to
the familiar file-store structure of computer systems; i.e., a root directory with
files and subdirectories which themselves conta ...