Moving Visibility centered on Characters

What would be really cool, I think, is if characters could be given a range of sight that reveals the area around them as the tokens are moved on the map.  If possible what would also be great is if the edge of the circle faded into black at an appropriate range.   And lastly what would be very cool would be if you can draw "walls" that the system understands as such and so visibility would be blocked by them, and players could not inadvertently move their characters through them.   

VB W. Some of your suggestions are already implemented in the Dynamic Lighting system.  You can set a reveal (light) radius around a token. As the token is moved it will reveal a section of the map. You draw walls on the Dynamic Lighting layer to block the reveal radius.  The two aspects that are not implemented are 'fade into black' and a block to prevent players from inadvertently moving past walls. Fade to black: Currently, the transition is an abrupt change.  Moving past walls: You can still prevent this from ruining surprises by using Fog of War in concert with Dynamic Lighting.  - Gauss

Gauss and Riley pretty much already said what there is to be said but here's my input anyway. There usually are 3 ways to record what players can see: Fog of War Lighting Lign of Sight Roll20 has 1 of the 3: Dynamic Lighting. It also has FoW but not in the sence I'm used to. You can't have the players "unlock" portions of the map by visiting them but not seeing the tokens etc. when they lose LoS/lighting. You either see everything or nothing. DL in Roll20 works well and does what it says behind the links posted by Riley. LoS keeps track of what a token can see regardless of lighting. Eg there can be two rooms on the map and they both have lightsources. Roll20 would allow the players to see inside both rooms even when there is a wall between these two rooms. The GM can prevent this with the FoW tool but like said earlier they then can't see the map area at all even if they have visited the room and it requires manual laibor. All these 3 have been done before so they are doable -> the missing 2 might be implemented in the future. There isn't a way to prevent players from moving a token over a drawn line. I have never seen anything like this in other softwares so I have no idea if it's possible/reasonable to do.

That's totally awesome.  Thank you!   I guess it means, though, that I didn't do a good job researching the system before making a suggestion. :p  ... my bad.  Anyway, thanks for the information.   And I do kinda think Fade-To-Black would be nice.