How do you get rid of what looks like a ghost model in your Project?

After working on your model in Lumion you notice that there is some other strange part of a model displaying on the screen.  It moves along with your main model but you can't see how to remove it.

Here's the steps to fix the model:

You have most likely assigned a Billboard Material to a part of the model.

In the Material Library:

1. Select one of the surfaces that form the 'ghost' model.

2. It should show that the material is a Billboard Material.

3. Change the material back to either the Imported Material or select some other Custom or Lumion Library Material.