Refer to Main Article: 

• Knowledge Base:  Why do Materials sometimes disappear when using LiveSync and a Section Box?

Example A:  A simple example of 2 walls.

1.  You have two walls in a model:

1.1:  The walls as seen in Lumion:

2. You Add a Revit 'Section Box':

3. In Lumion you apply materials to both walls, then save a Material Set file to store a copy of the materials you had applied in Lumion:

3.1:  The saved Material Set always only consists of Lumion Materials:

4.  You change the Revit focus/view to the right red wall only by adjusting the 'Section Box':

5.  Lumion is updated by LiveSync and now only shows the right wall (as expected):

5.1:  The Material Set when now saved will only include the Lumion Materials for the right (red) wall:

If you had resaved to the same Material Set file as in Step 3 then this is the only surface for the model and the only material in the Material Set.

6.  In Revit you bring back the other wall by changing or cancelling the 'Section Box':

7.  However now in Lumion there is no Lumion Material for the left wall.  Only the Imported Model Material - expected:

As far as LiveSync and Lumion are concerned there was no wall until now.  Until this change for the 'Section Box.'  It is not possible for Lumion to keep all the different states that might occur for the model.  When importing live, the model is the model you also see in Revit, which is what you expect.  As if you had used 'Visibility Graphics' or 'Hide element in this view' to hide some parts of the model.  The same would occur if you imported from a Collada DAE exported model and did updates (Re-Import) of the model at each time you changed the 'Section Box'.

8.  In Lumion there is no left wall material in the Material Set to apply back

It is now a different state of the model with different surfaces and different materials.

But there is if you had saved the Material Set when the left wall was visible and you had done your Material Edits.  And you did, but you later on overwrote that file with a different state of the models materials that as in 5.2 no longer includes the (left wall) material.

Now for the purposes of this example the Material Set in Step 5 (right wall only 'Section Box' view) was saved with a different file name to go back to the Material Set that corresponds to the state of the model when it was earlier edited to apply the Lumion Material - brown brick.

8.1:  Appling the older Material Set for left wall brown brick included in Material Set:

Continue with the House Example and some further details:

• Knowledge Base:  Example B.  A house design (sample Revit template).

or return the the main article:

• Knowledge Base:  Why do Materials sometimes disappear when using LiveSync and a Section Box?