Setting underlay parameter to null

I am trying to globally set all floor plan views to have no underlay. I thought simply using the set parameter node with ‘null’ would work but it is failing. ‘None’ and ‘-1’ are also failing. Any suggestions?



Hi Paul,

You can always check the type of required input by extracting the current value with “Element.GetParameterValueByName”. In this case the parameter value is a level element. My suggestion is to make a temporary level, select all the views you want to override, apply the temp level and finally delete the temp level. That will revert all the selected views to “None”. You can either delete it through the revit UI or use one of the delete nodes from the SteamNodes and packages.


This works great. Its also possible to create and then delete the Temp level in the same definition.

Thanks Dimitar

I’ve published a node called ‘View.SetUnderlayToNone’. It can be found on the BVN Dynamo package. It creates a new temp level then deletes it as recommended. It uses a string to filter which floor plans to update. This is currently set to our office standard (BVN alphabet series) but its pretty easy to modify for other users/offices. Thanks for your help.