This .NET class wraps the AcBrMeshControl ObjectARX class. 

The MeshControl class is the interface base class for mesh controls. This class defines the functions that are common to all mesh control derived classes, and cannot be instantiated as it has no meaning on its own. It is derived from RXObject in order to provide full service run-time type-checking, etc.

Autodesk.AutoCAD.BoundaryRepresentation.MeshControl
    Autodesk.AutoCAD.BoundaryRepresentation.Mesh2dControl

Public abstract Class MeshControl
Inherits RXObject

public abstract class MeshControl : RXObject;

Mesh controls affect the quantisation and shape of element generation in a mesh. Mesh controls are inexact and may possibly conflict, so are listed in the order in which they are applied by standard textbook mesh generation algorithms. Granularity controls (i.e., maximum initial subdivisions and maximum node spacing) are fairly coarse and only affect the initial discretisation steps. Except for cases of extreme curvature in NURBS surfaces, element density in the interior mesh should fairly accurately reflect the control settings; whereas the density of elements along the surface boundaries may be much higher than requested due to node sharing with adjacent faces. 

Depending on the type of surface(s), it is generally necessary to set only one control. Distance tolerance has the largest impact on the mesh, and is especially useful for effecting high element density in areas of tight curvature. Angle tolerance is most useful for complex surfaces w/ knobs, whereas node spacing is mostly used for planar surfaces as it is the only way to guarantee that the surface is subdivided into more than one element. 

Switch a control on by setting it to a legal value, and switch it off by setting with no argument supplied.

Mesh2dControl