This .NET class wraps the AcBrMesh2d ObjectARX class. 

The Mesh2d class is the interface class for 2D meshes. This class defines the functions that are pertinent to a two-dimensional (or faceted) mesh of either an entire solid or an individual surface. 

A 2D mesh is a mesh that maps to a 3D face set, and thus has associated geometry. The geometry, however, is stored at the individual elements and nodes, as are the mappings back to the original brep topology. A 2D mesh can also be thought of as a wire network, and its element set can be used to define a surface wireframe model. Nonmanifold edges and vertices from the 3D face set are ignored and are not mapped to the mesh. Degenerate elements are discarded, along with their unique nodes.

Autodesk.AutoCAD.BoundaryRepresentation.MeshEntity
    Autodesk.AutoCAD.BoundaryRepresentation.Mesh
        Autodesk.AutoCAD.BoundaryRepresentation.Mesh2d

Public sealed Class Mesh2d
Inherits Mesh

public sealed class Mesh2d : Mesh;

Mesh2dControl, Mesh, Mesh2dElement2dCollection, Mesh2dElement2dEnumerator