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Subsection 5.4.2: Editable Surfaces Up Section 5.4: Creating and Editing a Mesh Chapter 6: Materials

### 5.4.3 Editable Meshes

If the object is a so-called editable mesh the Mesh panel will list some mesh editing tools. Editable meshes don't have a geometry object associated with it so the mesh, or at least its surface, defines the geometry implicitly. This has some important consequences related to applying boundary conditions to an editable mesh. Any change to the mesh may also change the corresponding geometry and as a consequence any data that was associated with the previous geometry may become invalid.
Important Note. It is best to first make the necessary modifications to an editable mesh before you apply any boundary conditions or loads. Any modifications to an editable mesh may invalidate boundary conditions and loads.
Editable meshes can be edited on several levels, namely the object level, the element level, the face level, the edge level, and the node level. The element, face, edge, and node level are also referred to as the sub-object levels. When an object is an editable mesh (or editable surface), the Graphics control bar, will show additional buttons that allow you to select mesh items.
Enter the element level.
Enter the face level.
Enter the edge level.
Enter the node level.
When none of the sub-object levels are active, the object level is automatically active. If you are in one of the sub-object levels, you can return to the object level by deselecting the selected button on the selection tab or pressing the Esc button.
The Graphics control bar also provides several options that affect the way mesh items can be selected.
• Select connected: select all items that are connected to the selection. An angle criterion is used in addition to a connectivity criteria. The angle for this criterion can be set in the edit field next to this button.
• Select via closest path: This will select all items via a closest-path criterion between two selected points.
• Select backfacing: ignore items that are on the back of the mesh (and therefore not visible from the current viewing position).
To edit the geometry select the Mesh panel. Several tools will be displayed that allow you to modify the mesh. Most of these tools require a specific mesh selection mode to be active.
• Auto Partition: Partitions the surface, edges, and nodes of the mesh based on an angle criterion. If the Repartition elements is checked, the elements will be partitioned based on their connectivity.
• Partition: Partition the current mesh selection.
• Smooth: This option works only for triangular shell meshes. It smooths the mesh by iteratively moving points towards their neighbors and often results in better-shaped triangles and more evenly distributed nodes.
• Iterations: Number of iterations to apply the smoothing
• lambda: weight factor for scaling
• Preserve shape: tries to preserver the overall shape of the object.
• Project: project the smoothed nodes back to the original mesh
• Discard Mesh: Discards the volume mesh and only retains the surface as a shell mesh.
• Mirror: Mirror the mesh.
• TetGen: Replace the current mesh with a tetrahedral mesh.
• Weld Nodes: Weld the selected nodes together that are within a distance specified by the threshold edit field. Welding is useful to connect touching parts together. However, be aware that you might create unexpected errors in your geometry this way since the effects of welding are not always visible.
• Refine Mesh: Refines the triangular shell mesh by dividing each triangular face into 4 triangular faces. In this method a new node is added at the center of each edge of the triangle and new triangles are created using these new nodes.
• Convert: Convert the element type to a different type.
• Add node: Add a node to the model at the specified coordinates.
• Invert: Invert the selected elements.
• PostBL: Create a boundary layer from the selected surface faces.
• Shell Thickness: Set the shell thickness for the selected elements.
• Set Fibers: Set the fiber orientation of the selected elements.

Subsection 5.4.2: Editable Surfaces Up Section 5.4: Creating and Editing a Mesh Chapter 6: Materials