With the upcoming release of MapTool 1.4.2, GMs will be able to add a layer of Vision Blocking to stamps and tokens. This means Players will be able to see an object but that object will block all light and sight from passing through it. This comes in handy for doors, statues, vehicles, and large tokens. When combined with MapTools Macro Bag of Tricks drop-in resource, you can create the following effect on doors.
1.4.2 should release in the beginning of July. You can get a preview with MapTool Dev/Test version 1.4.6.