In 4D, the On Mouse Moved event normally fires when the mouse pointer moves over an object. However, this event can also be triggered even if the mouse is stationary, provided the pointer is positioned over the object and a modifier key (such as Ctrl, Alt, or Shift) is pressed.

This feature enables you to detect user interactions involving keyboard modifiers without requiring actual mouse movement. It can be used to enhance UI responsiveness by reacting to key presses combined with mouse positioning, allowing for more dynamic and intuitive user experiences.