On a very basic example using Monitor File, I couldn't reproduce any problems like this where materials get dropped or mapped differently.
Perhaps you can be a bit more specific with the steps/setup?
The appearances are applied at what level in SW?
You are modifying the appearance settings in Visualize after import? OR assigning entirely new/different appearance?
You are allowing Visualize to reload the entire model? Or are using part level "Re-import Part" command?
What 2017 service pack are you running?
Ron, Thanks for your reply. I'm sorry its taken me ages to read it and reply.
I'm attributing different colours to bodies, parts or surfaces in SW to define them from one another then importing into Visualize as the SW files, then I'm attributing new materials, some downloaded from Poliigon for example. So I am both assigning and modifying entire new appearances in Visualize.
I'm then making updates to the SW model and re saving and because I'm using monitor file, visualise offers me the opportunity to re-import. However when I do that often the materials assigned to one object then reassign to another or drop off or the mapping goes crazy and the colours assigned in SW don't pull through into SWV. For example a brick wall with a texture scaled and mapped to get a certain look. Upon re-import the bricks often become huge and maybe map in another orientation.
I'm using Visualize 2017 SP3 and SW 2015 SP5