Beta v4.1.14: FoW - additional (unexpected) revaled areas after update

[Ecks]

With a campaign from Live v4.1.13 opened in Beta v4.1.14, on the map the players are currently on, the existing Fog of War data now reveals more than what the players have seen, including areas behind walls that the players should not see. I re-created this in a new 5E campaign with no extensions. Note that the attached screenshots may contain spoilers for Tomb of Annihilation.

To recreate:

In Live v4.1.13

New 5E campaign
Load Tomb of Annihilation module
Open Map: Player Map - Chambers of Horror
Drop a PC on the map with a LIGHT effect
Move PC around to generate the following Fog of War (player vision preview ON), and leave token in the position indicated: Capture.4.1.13.JPG (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51385)
Save and Exit

In Beta v4.1.14

Copy campaign from Live
Open the map, select the player token, and observe additional revealed areas that are behind walls: Capture.4.1.14.JPG (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51386)

Large area in center of map
Inside walls of the "maze" area in the bottom right



I can email you the campaign file with everything in state if that would be useful.

FGU v4.1.14
5E ruleset v2022-01-25

[Ecks]

After additional testing, I found updating from the old version is not necessary, it can be reproduced in just v4.1.14 from a clean state.

In a new 5E campaign, in v4.1.14:

Load Tomb of Annihilation module
Open map: Player Map - Chambers of Horror
Drop a PC on the map with a LIGHT effect
Turn on Player Vision Preview
Move the token to reveal the map in the following path: Capture.BeforeMove.JPG (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51387)
About when the token reaches the red arrow in the above screenshot the Fog of War will start to reveal hidden areas that the token has not seen: Capture.AfterMove.JPG (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51388)

[Moon Wizard]

Thanks for reporting, and providing very specific steps. It looks like the FoW simplification needs a little adjustment for full "circuits". I've escalated to @cpinder to review.

Regards,
JPG

[Moon Wizard]

The latest version of the FGU client pushed to the Test/beta channel today should address this issue, as well as improve the simplification routines relative to curved walls.

Regards,
JPG

[Ecks]

I tried out the latest test version and I'm no longer seeing the issue with fog of war disappearing in the inner area of a circuit.

One thing I am seeing is that along walls sometimes the Fog of War will reveal beyond player vision (i.e. beyond a LoS wall). I tested this a bit on the Tomb of Annihilation, Player Map - Gears of Hate, and in some cases the Fog of War revealed secret passages beyond what the player token had visibility too. This one isn't as easy to re-create, but here is an example (warning, potential spoilers for Tomb of Annihilation):

On Tomb of Annihilation, Player Map - Gears of Hate.

PC on CT with effect LIGHT: 20 light
Drop PC token in position indicated on this image (at the 200' mark) and move in the following path (basically down the hall and back to starting point): FogOfWarPath.jpg (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51600)
As the token moves, the PC token Fog of War reveals inside the wall (beyond the wall occluders), even though the token never had vision/Line of Sight to it: FogOfWar3.jpg (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51601)

[Ecks]

One other scenario where a hidden area was inadvertently revealed:

Tomb of Annihilation, Player Map - Vault of Reflection
Drop token on map here and queue the following movement: Move.jpg (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51608)
After move is completed, note FoW is revealed beyond the boundary of the wall, revealing a hidden area: After.jpg (https://www.fantasygrounds.com/forums/attachment.php?attachmentid=51609)

[Moon Wizard]

It looks like the line simplification library we are using is trying to interpolate the corners slightly, which is not what we want to happen. @cpinder is looking at writing our own routines to base it on angle change thresholds, instead of standard line simplifying algorithms.

Regards,
JPG

[Moon Wizard]

We've pushed a new update with a different simplification algorithm that should improve the FoW calculations. We do expect some minor "simplifications" to occur, but they should be barely noticeable.

Regards,
JPG

[Ecks]

Awesome, thanks! The fog of war looks good so far with the few maps I tried.

[BushViper]

Awesome, thanks! The fog of war looks good so far with the few maps I tried.

Are you experiencing any significant performance improvements with the FoW changes?