There are a few settings in Revit that can be hard to control. One of those is a view’s ‘Underlay’ setting. This tutorial will show you how to globally control this parameter so that when exporting or printing, you can be sure the view will display as required. Special thanks to Dimitar Venkov for helping with this solution via the Dynamo forum.
What is the view’s underlay?
According to Autodesk’s help file, underlays “displays another slice of the model under the current plan view. That slice of the model can be from above or below the current level. The underlay appears dimmed and is visible even in hidden line. The underlay is useful to understand the relation of components on different floors. Normally, you would turn off the underlay before exporting or printing the view.” And here lies the problem.
While it is possible to set the ‘Underlay Orientation’ within a view template, it is not possible to set the ‘Underlay’ to ‘None’. This limitation seems a pretty massive oversight from Autodesk and defeats the purpose of having view templates in the first place. Furthermore, creating a ‘View List’ schedule will not render available the underlay field. Therefore, a view’s underlay parameter can only be controlled by navigating to each view and manually changing it. This process can be incredibly time-consuming if users have willfully changed the underlay settings on views that are to appear on sheets.
To solve this limitation, BVN has created the ‘View.SetUnderlayToNone‘ Dynamo node. The node extracts all the floor plan views in the project and then filters these views based on the ‘BVN alphabet series’ parameter. While this node is specific to BVN standards, it can be easily modified to be based on other custom parameters. The script essentially creates a new temporary level and assigns this level to each of the views. This level is then deleted, resulting in a “None” underlay.