Use the Activating Allowed Values node () to specify the conditions to dynamically allow values from the list of allowed values specified in the parent User Input node. The condition can depend on user inputs in the parent feature or property, or any other user input in a property within the physics interface. Conditions can either be true if the other user input has a specified value or if it is active. The Settings window has the following sections:

Add the allowed values from the parent node to the Allowed values list that this node can activate. When the condition specified in the Activation Condition section is true, the allowed values for the parent user input contain the allowed values specified in the list.

The activation condition can depend on user inputs in the parent feature, parent property, or some property. If the user input is under a feature or property, which can contain other user inputs, you can directly refer to any of those user inputs by choosing By reference in the Specify user input list. You then choose the user input from the User input list, and finally add or enter the values that activates the user input in the Activating values list. This list differs depending on the user input you refer to.

The last option in the list is In expression. This is a very general tool that can evaluate an expression of relations and Boolean operators. It also supports some special functions and names, see the section about Usage Condition for more details.

Select the Invert condition on input values check box to invert (negate) the condition.

The Require input is active check box is selected by default. It is only applicable when specifying a user input to check by reference or by name, not for expressions. When selected, the activation condition is only true if the checked user input is also active as decided by its activation conditions. For expressions, you can achieve the equivalent logic using the isActive operator.