In our previous scene we defined a rotation that was passed by a Constant Node to a Math Node. Very often such a parameter is subsequently modified as needed. This is no problem when dealing with a single parameter but can become quite tedious when several parameters have to be modified in a variable fashion. You would have to rummage through each XPresso Expression and adjust each one individually.
For such a scenario you can create custom parameter fields in the attributes of the corresponding objects. In our example we can edit the speed vector in the Attribute Manager via an XPresso interface. These attributes are called User Data. These can be added to any object whose parameters can be displayed in the Attribute Manager. The will also remain unchanged when the respective object is copied or the scene is saved. User Data should be used if values must be entered manually in XPresso. This makes working with the scene in general much easier.
To create User Data, select the object to make its parameters visible in the Attribute Manager and select
As you can see in the image below the User Data are stored in a separate tab in the Attribute Manager. Here the values can be entered that will be processed in the XPresso Expression.
After we have assigned User Data to an object we can drag it from the Object Manager into the XPresso Editor window. After doing so, right-click on the red corner of the Cube object’s Node to view the User Data menu information for that object: