# Verifying the mesh.
The objects of your physical structure are meshed based on a specified mesh density expressed in cells/λ<sub>0</sub>. The default mesh density is 10 cells/λ<sub>0</sub>. To view the EM.Libera's PO mesh, click on the [[File:mesh_tool_tn.png]] button of the '''Compute Simulate Toolbar''' or select '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] > Simulate > Discretization [[File:larrow_tn.png]] Shoe > Show Mesh''' or use the keyboard shortcut '''Ctrl+M'''. When the wire-frame PO mesh is displayed in the Project Workspaceproject workspace, [[EM.Cube|EM.CUBE]]'s mesh view mode is enabled. In this mode, you can perform view operations like rotate view, pan, zoom, etc. However, you cannot select or move or edit objects. While the mesh view is enabled, the '''Show Mesh''' [[File:mesh_tool.png]] button remains depressed. To get back to the Normal View normal view or select mode, click this button one more time, or deselect '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] > Simulate > Discretization [[File:larrow_tn.png]] > Show Mesh''' to remove its check mark or simply click the '''Esc Key''' of the keyboard."Show Mesh" generates a new mesh and displays it if there is none in the memory, or it simply displays an existing mesh in the memory. This is a useful feature because generating a wire-frame mesh may take a long time depending on the complexity and size of objects. If you change the structure or alter the mesh settings, a new mesh is always generated. You can ignore the mesh in the memory and force [[EM.Cube|EM.CUBE]] to generate a mesh from the ground up by selecting '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] Discretization [[File:larrow_tn.png]] Regenerate Mesh''' or by right clicking on the '''3-D Mesh''' item of the Navigation Tree and selecting '''Regenerate''' from the contextual menu.
"Show Mesh" generates a new mesh and displays it if there is none in the memory, or it simply displays an existing mesh in the memory. This is a useful feature because generating a PO mesh may take a long time depending on the complexity and size of objects. If you change the structure or alter the mesh settings, a new mesh is always generated. You can ignore the mesh in the memory and force [[EM.Cube]] to generate a mesh from the ground up by selecting '''Menu > Simulate > Discretization > Regenerate Mesh''' or by right clicking on the '''3-D Mesh''' item of the Navigation Tree and selecting '''Regenerate''' from the contextual menu.
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To set the PO mesh properties, click on the [[File:mesh_settings.png]] button of the '''Simulate Toolbar''' or select '''Menu > Simulate > Discretization > Mesh Settings... '''or right click on the '''3-D Mesh''' item in the '''Discretization''' section of the Navigation Tree and select '''Mesh Settings...''' from the contextual menu, or use the keyboard shortcut '''Ctrl+G'''. You can change the value of '''Mesh Density''' to generate a triangular mesh with a higher or lower resolutions. Some additional mesh [[parameters]] can be access by clicking the {{key|Tessellation Options}} button of the dialog. In the Tessellation Options dialog, you can change '''Curvature Angle Tolerance''' expressed in degrees, which as a default value of 15°. This parameter can affect the shape of the mesh especially in the case of [[Solid Objects|[[Solid Objects|solid objects]]]]. It determines the apex angle of the triangular cells of the primary tessellation mesh which is generated initially before cell regularization. Lower values of the angle tolerance result in a less smooth and more pointed mesh of curved surface like a sphere.
[[File:wire_pic5_tn.png]]
The regular wireframe mesh of a PEC sphere.
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=== Customizing the Mesh ===
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[[File:wire_pic4.png|thumb|360px|[[MoM3D Module]]'s mesh settings dialog]]
[[File:PO5.png|thumb|300px|The Tessellation Options dialog.]]
To set the wire-frame mesh properties, click on the [[File:mesh_tool_tn.png]] button of the '''Compute Toolbar''' or select '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] Discretization [[File:larrow_tn.png]] Mesh Settings...'''or right click on the '''3-D Mesh''' item in the '''Discretization''' section or the Navigation Tree and select '''Mesh Settings...''' from the contextual menu. The MoM3D Mesh Settings Dialog opens up. You can change the mesh generation algorithm from the drop-down list labeled '''Mesh Type''' and select one of the two options: '''Regular Wireframe''' or '''Structured Wireframe'''. You can also set the '''Mesh Sampling Rate''', whose default value is 20 Cells/λ<sub>0</sub>.By default, [[Surface Objects|surface objects]] or solids are wire-framed at the mesh cell size. Therefore, each wire segment of the wire-frame mesh contains one cell. Another parameter that can affect the shape of the mesh especially in the case of [[Solid Objects|solid objects]] is the '''Curvature Angle Tolerance'''. This parameter expressed in degrees determines the apex angle of the triangular cells of the structured mesh. Lower values of the angle tolerance will results in more pointed triangular cells.
[[File:wire_pic6_tn.png|800px]]