If you have a user input in a property that you use as a loop parameter in physics features or coupling features, you can add an Update User Input Event node (). If the value or size of the loop parameter should affect the size or user interface of the user inputs in the physics features or coupling features you need to update those user inputs every time the property user input is changed. Use an Update User Input Event for that purpose. To add an Update User Input Event node, right-click a Property node and select it from the context menu.