The aim of this chapter is to review some methods designed for mesh modification and manipulation (except for those concerning mesh optimization which will be discussed in the next two chapters). Provided with one or several meshes we are concerned with the methods that manipulate this (these) mesh (es) in various ways. Among the points of interest here, we first review mesh transformations with a geometric nature, the way in which two meshes can be merged into a single one, refinement techniques and various operations related to the attributes associated with the mesh in question.

Geometric mesh transformations are briefly reviewed together with transformations resulting in a global or a local mesh refinement and methods for geometric type change. In addition we discuss how to merge two meshes (sharing a common boundary part). Then, we give some information about node construction and node numbering for elements other than P ¹ elements (namely where the nodes can be different from the vertices). Various representative finite elements are listed to illustrate how to construct (to number) the nodes. Then we focus on how to optimize, in some sense, both the vertex (node) and the element numbering in a mesh. To conclude the chapter, various other aspects are discussed (including how to manage the mesh physical attributes properly, how to use two different meshes, etc.).