To reset the finite element mesh and / or the discretization, select Reset Mesh from the toolbar or the Mesh menu.
Resetting the mesh is separated into two steps:
Resetting the mesh.
Resetting the discretization.
This is because there will be times when you only want to reset the mesh, but not the discretization. For example:
you may want to preserve a Custom Discretization for further customizing (remember that all Custom Discretization is lost when the discretization is reset), or
you may only want to change the Element Type from triangles to quads, or vice versa, but retain the same discretization.
If the model has been discretized but not meshed, then Reset Mesh will reset the discretization only.
If you delete the mesh accidentally, remember that you can always use the Undo option to Undo any actions in Slide.