To Activate or Deactivate Knots
1. Perform one of the following operations to change the status of one knot:
Select it.
Select an inactive knot, right-click, and choose Activate from the shortcut menu.
Move the pointer over an active knot, right-click, and choose Deactivate from the shortcut menu.
2. To activate all deactivated knots, right-click on the surface and select Activate All. All knots are activated.