The transition from an arbitrary surface description to a proper mesh
still represents a difficult task. This is particularly so when the surface
description is based on data that does not originate from CAD-systems,
such as data from remote sensing, medical imaging or fluid-structure
interaction problems. Considering the rapid advance of computer power,
together with the perceived maturity of field solvers, an automatic
transition from arbitrary surface description to mesh becomes mandatory.

To date, most of the field solvers based on unstructured grids have only
considered body-conforming grids. After all, one the perceived strengths
of field solvers based on unstructured grids is precisely the ability to mesh
arbitrary domains.

For structured grids so-called embedded mesh, immersed body or
ficticious domain techniques have been used for many years as a way
to discretize geometrically complex domains. The use of such
techniques within adaptive, unstructured grid solvers is relatively recent.

The combination of body-fitted functionality for some portion of the domain,
together with embedded mesh or immersed body functionality for another
portion of the domain offers great advantages, which are increasingly
being exploited.

The talk will review the methodologies pursued so far, address
implementational issues and show the possibilities such techniques
 offer.