As mentioned earlier, highly incongruous meshes should always be avoided. Sometimes EM.Cube's default mesh may contain very narrow triangular cells due to very small angles between two edges. In some rare cases, extremely small triangular cells may be generated, whose area is a small fraction of the average mesh cell. These cases typically happen at the junctions and other discontinuity regions or at the boundary of highly irregular geometries with extremely fine details. In such cases, increasing or decreasing the mesh density by one or few cells per effective wavelength often resolves that problem and eliminates those defective cells. Nonetheless, EM.Cube's planar mesh generator offers an option to identify the defective triangular cells and either delete them or cure them. By curing we mean removing a narrow triangular cell and merging its two closely spaced nodes to fill the crack left behind.
[[File:PMOM44.png|400px]] [[File:PMOM42.png|400px]]
Figure 1: Deleting or curing defective triangular cells.
EM.Cube by default deletes or cures all the triangular cells that have angles less than 10º. Sometimes removing defective cells may inadvertently cause worse problems in the mesh. You may choose to disable this feature and uncheck the box labeled "'''Remove Defective Triangular Cells'''" in the Planar Mesh Settings dialog. You can also change the value of the minimum allowable cell angle.
[[File:PMOM43(1).png]]
Figure 2: Setting the minimum allowable angle for non-defective triangular cells.
=== Locking Mesh Of Object Groups ===