There isn't a really good way of doing this right now. There are some API scripts (Pro Subscriber Perk) that let you simulate it by having invisible tokens that players control (so see out of ) but aren't aware of, then updating their sight and location based on the location of other tokens. It works, but is a bit tedious. On Plus and lower subscriptions, there isn't a good solution other than just making it clear to your players that you shouldn't go across the window spaces, possibly with a known color of line or other marking. This did come up as a possible future improvement and has been talked about on the Community Roundtable recently. You can check the past videos and you might want to submit a question about it for the next one in a few weeks. Check out: <a href="https://app.roll20.net/forum/post/8625733/community-roundtable-may-21-at-5pm-6pm-pt" rel="nofollow">https://app.roll20.net/forum/post/8625733/community-roundtable-may-21-at-5pm-6pm-pt</a>
