July 28, 2011, 05:04:04 pm
All of the models you import are placed in the users/.../My Documents/Lumion folder. When a project is open, the objects in that project can be removed from the scene; however, they are not removed from the library. It is not possible to delete imported objects from the object library if those objects are or were present in the currently open scene.
If an object is removed from the library a red question mark will be in the place of the deleted object when the scene is reopened. For example, if you open a new scene in which no imported objects are present you can then delete all objects in the Lumion library. Then when you open the previously saved scene which contained the imported objects, you will only see red question marks in place of the imported objects.
The Lumion library is not the same as the file location of the original model. Deleting the original file does not remove it from the Lumion library. Therefore, if you have two computers and you want to share projects between the two, you simply copy the My Documents/Lumion folder to the same location on the second computer. However, because of this limitation a change to the materials of an object in one scene affects all other scenes in which that object is present.
I hope this explanation is not overly complicated.