I have a ‘master’ model of a large-ish house inserted into a secondary model where I am adding interior wall surface detail and cutting additional sections to make interior elevation views to include in architectural construction drawings. Something akin to what I understand @Sonder does. In some of the views it is handy to use the section planes that come with the ‘master’ model to cut off the visibility of parts of the model that are visible in the distance through openings & etc. One section active in the local model, and a second in the inserted ‘component’ master model. I get scenes set up and looking good, but then when I update and reload the ‘master’ model the sections that come with it all reset to whatever was last saved in that model.
I recently logged a bug report about this. One possible work around is to put the contents of the component into a group, or component. Then when you edit the reference model (the master model), at the top level you have a component, and inside that is the geometry and the section plane. Working that way seems not to reset the section planes when you do the reload.
The problem seems to be that the state of section planes that are at the root level of the master model are ignored when you reload that into the main scene, and having everything one level down appears to work ok.
Colin is correct. Create a group of the imported model and a section plane that you want to activate for a particular scene. That way when you update the model you don’t lose the activated section cut. It’s very easy to do since you have the reference model section already set. Just add the new section and activate it in your scene. Do it once and your done.
This is a great method for site plans when you want to show an active section of the structure, but not cutting into the site.