Recently a client of ours had a problem whereby they had grass visually showing on the inside of an imported Revit building. See the screenshot below. The customer tried to edit the Concrete Floor material within Lumion but could not get the grass removed.
What must have happened was that somehow the client had perhaps elsewhere assigned the Lumion Landscape Material onto the imported Revit Concrete Floor Material. Because Lumion’s material assignments work across Revit Material name, all the Concrete floor objects would then get the Lumion Landscape Material even if the objects are on the inside. Also if you set up the grass tool inside Revit then grass would appear on top the Landscape Material.
See below the Lumion Material setting which was used to assign Landscape Material onto a Revit Imported Material.
Then to add grass to the Landscape Material you would select the Landscape main menu item on the left and then enable grass on the toolbar.
What solved the issue was to select the Material Editor Main menu on the left of Lumion and then the Concrete Floor material. See below.
Then click the Material button bottom left.
Then the Use Imported Material button as below. This will change the object’s current material to that of how it looked as when you initially imported the model. See below.
Finally select the Confirmation Tick mark on the right to assign the material.
The conclusion is to remember that Materials in Lumion is mapped to a Revit material name once the Revit Model is exported to Lumion via the Lumion Revit Bridge and imported. So all the similar Revit named materials will have the same Lumion material assigned.
If you want any variation in materials inside Lumion you’d have to , prior to importing the Revit Model (or use the Model Update function) duplicate the Revit Materials into various Material names. One for each different material so that you can assign a Lumion material to each Revit material.