Many of the mesh tools involve selecting or manipulating nodes. Ensure that the nodes in the part are visible and selectable by activating the required layers in the Layers pane.
Use the Project Mesh command to project the chosen mesh back towards the surface of the parent surface. This command is useful when your mesh has become unexpectedly deformed and no longer follows the surface of your model.
Use the Remesh Tetras tool to selectively change the density of the tetrahedral (3D) elements in a portion of the model.