Token Vision Resetting Upon Newly Created Effects

[Chinzi]

Summary: I wanted an area to be in magical darkness that darkvision can't see through, but the party has an item that provides light, so they can only see within that range. To achieve this effect, I selected all of their tokens and removed/turned off token vision. I gave one of them a light source. This achieved the desired result, however anytime I create a new effect on a character in the combat tracker it resets their original token vision settings automatically. Is this unavoidable?

Ruleset(s): Dungeons and Dragons 5e

New Campaign: Created a year ago in Unity

Extensions/Themes: Syrinscape Online Sounds v16

Modules Loaded: Sword Coast Adventurer's Guide, Dungeon Master Guide, Elemental Evil - Player's, Monster Manual, Player's Handbook, DM's - Maps, Mordekainen's, Tasha's, Volo's, Xanathar's

Operating System / Language Setting: Windows / English

Steps to Reproduce: Set ambient light mask for entire map. Select token with darkvision and remove their token vision or turn it off. Add an effect to that token in the combat tracker.

[Zacchaeus]

The recommended approach to adding light sources and vision to a PC is to apply the effect from their actions tab, or use one of the preset effects from the effects menu (you can create your own light effects in Options > Token Lights and those will also appear in the effects menu)

Another thing you can do is add darkness lights to the map which will block all light and vision which cannot penetrate magical darkness (that is truesight). The images below illustrate this.

[Chinzi]

So, my use case may be fringe, but there are still some inconsistencies that warrant investigation to make the features more robust and consistent. Here are some points:

Vision Override:
Let's say there is a situation that calls for reducing vision range. Using effects as per your suggestion, I can easily limit a human's vision range by adding a VISION: 10 effect. This works even with a Light source nearby, which may not actually be intended functionality.

48509

A gnome with darkvision, however, completely ignores a VISION: 10 effect. It also ignores a VISION: 10 darkvision effect

48510
48513

If I remove the gnome's token vision, though, then the VISION: 10 effect works.

48511

The moment I create a new effect on the gnome, their token vision resets, and they have darkvision out to 60' again.

48512

The situations react irregularly, which is odd, even if you don't intend to support a use case of limiting vision ranges.

[Chinzi]

Truesight and LoS Walls:

Gnome with VISION: 60 truesight effect working as expected.

48514

Adding a 20/20 darkness light source within the gnome's vision range suddenly causes the gnome to ignore all LoS walls, and it can see out to 60' in all directions.

48515

[Lo Zeno]

So, my use case may be fringe, but there are still some inconsistencies that warrant investigation to make the features more robust and consistent. Here are some points:

Vision Override:
Let's say there is a situation that calls for reducing vision range. Using effects as per your suggestion, I can easily limit a human's vision range by adding a VISION: 10 effect. This works even with a Light source nearby, which may not actually be intended functionality.

48509

A gnome with darkvision, however, completely ignores a VISION: 10 effect. It also ignores a VISION: 10 darkvision effect

48510
48513

If I remove the gnome's token vision, though, then the VISION: 10 effect works.

48511

The moment I create a new effect on the gnome, their token vision resets, and they have darkvision out to 60' again.

48512

The situations react irregularly, which is odd, even if you don't intend to support a use case of limiting vision ranges.

Two things I notice here (keep in mind I'm not a FGU developer so I might be wrong, what I'm going to say here is my understanding of the vision and lighting feature so far):

The first is: when you apply VISION: 10 to the gnome with Darkvision, it doesn't "ignore" the VISION: 10 effect: they are both applied. You incorrectly assume that applying the VISION: 10 effect will limit ALL vision of a character, but in FGU a character can have multiple "visions".
Imagine a character with Darkvision 60 ft AND Blindsight 10 ft: they have two different ranges, and you can give both visions to a character by creating two effects and applying them both to the character. If something blocks his darkvision (e.g. a Darkness spell), he can still rely on his Blindsight even if it's only 10 ft. The "VISION" effect is, effectively, the "normal eyesight" vision: when you apply VISION: 10 to the gnome, you are effectively saying that the character has "normal eyesight working for up to 10 ft", but his darkvision (which is a different vision) will still have its normal range. If you want all visions to be limited to 10 ft, you'll have to specify the range for both, or use the VISMAX: effect (see https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/1315930113/Player+and+NPC+Token+Vision+on+Maps#Special-Vision-Modifiers-with-Blinded-Condition )

The second: your gnome probably has Darkvision set in their character sheet, under "Senses", as "Darkvision 60": that will conflict with the Effects that you set, and I believe it actually has some sort of precedence over effects, so if you give them VISION: 10 darkvision the character will still use the Darkvision range set in the character sheet. I think that's also what makes the gnome's vision reset each time you add a new effect to the character: FGU reads the character sheet to see how to apply the effect, reads the "Senses" field, reapply the original vision as it is set there.

Take this with a grain of salt though, because as I said I'm not one of the devs

[MrDDT]

Just FYI, Darkness effect is in beta and has errors they already came out saying that it's being worked on.

Example is
Darkness (spell); LIGHT: 15/15 darkness
VISION: 120 devilsight

This will cause that person to see thru wall LOS.