Efficient modelling of many problems in the finite-element analysis of
structural and other continuum problems requires substantial simplifi
cation of the design geometry. Tools are needed for the efficient tran
sformation of the detailed design geometry into an appropriate analysi
s model. It is argued that the medial axis and surface transform of ge
ometric models provide an alternative representation that has many att
ractive properties for analysis feature recognition and simplification
. Strategies for identifying possible idealizations, controlling their
application, and estimating the associated errors appear feasible. So
me requirements for geometric-modelling tools are identified.