Fimbulvetr

The great winter doesn't wait for you to finish shovelling.

What it does

In the vanilla Deep North, snow you shovel away or trample down never comes back. Fimbulvetr lets it fall again. Shovelled paths, trenches and footprints slowly fill back in towards the ground's natural snow depth, and a blizzard buries them fast. Broken Ice Sheets freeze over again too.

• Weather-driven. In clear weather, snow drifts back slowly. In snowfall it builds up faster, and in a blizzard it piles up fast. Weather between light snow and a full storm gets a speed in between.
• Never deeper than nature. Snow only refills up to the depth the world generated there, so untouched land never gets buried.
• Snow levels itself out. Banks that walking and shovelling push up settle back down, and snow smooths out with the ground around it, so trampled ground doesn't grow spikes.
• Paths stay clear. Paths you make with the hoe, dirt or stone, never snow over, so you can lay out routes through the Deep North.
• Shelter keeps ground clear. Ground under floors, roofs or rock overhangs, or inside a Shield Generator's dome stays clear. Fires can keep snow away too if you switch that on (fimbul firesnow on): torches and campfires clear 4 m around them, a lit Eternal Pyre 20 m.
• Time away counts. When you come back to an area, or after you sleep, the snow that fell meanwhile is added at the calm rate, so old tracks are already filling in when you arrive.
• Ice freezes over again. Broken Ice Sheets refreeze a piece at a time, growing back from the ice that's left: slowly in clear weather, quickly in a blizzard. A sheet broken completely is kept so it can freeze over too, and sheets the game already deleted (even before you installed the mod) are put back as open water, so the ice returns to the world's original layout. Time you spend away (or asleep) counts too, at the clear-weather pace, and is caught up as soon as you come back. Ice never refreezes within 30 m of a player while you watch, or around a boat or a creature. Docks and other buildings get frozen in like anything else; only heat keeps ice away.
• Fire keeps water open. No ice refreezes within 8 m of a lit fire: torches, campfires, braziers, hearths and other heat sources. A lit Eternal Pyre goes further: it thaws all ice within 40 m and keeps it away, so build one to keep a harbour open.
• Light on performance. Only areas near you are updated, and the terrain is redrawn only once a visible amount of snow has built up.

Snow on buildings isn't changed. It still builds up and causes damage exactly as in vanilla.

Installation

Install with r2modman or the Thunderstore Mod Manager; BepInExPack Valheim is installed automatically as a dependency. No Jötunn needed.

Manual install: put Fimbulvetr.dll in Valheim\BepInEx\plugins\Fimbulvetr\.

Multiplayer: client-side. The dedicated server doesn't need it. Snow comes back in an area while a player who has the mod is in charge of it (usually whoever is standing there). Players without the mod still see the snow come back. To keep things consistent, everyone who visits the Deep North should install it.

Removing the mod: safe at any time. It only changes the snow depth stored in the game's normal terrain data, plus one timestamp per area and per broken ice sheet and a list of path spots per area. Ice sheets broken completely while it was installed stay as open water once it's removed.

Settings

BepInEx\config\com.chase.fimbulvetr.cfg

With the defaults, a 1 m deep trench refills in about 4 minutes in a blizzard and in about 1.5 hours of clear weather.

Console command

Open the console with F5 (start the game with -console).

fimbul                  current weather, refill speed, ice sheets and the mod's cost
fimbul storm|snow|calm  force a refill speed, for testing
fimbul off              back to the real weather
fimbul disable|enable   switch the mod off or on (saved to the config)
fimbul firesnow on|off  fires keep snow away, or not (saved to the config)
fimbul slopes on|off    snow-raised ground looks like snow, or as in vanilla
fimbul hitches on|off   log long frames with what the mod did in them

Known limitations

• Tested on a dedicated server with one player. Several players in the Deep North at once is less tested, so bug reports are welcome.
• Snow that fell while an area was unloaded counts at the calm rate, because nobody saw that weather.
• Tracks made before installing the mod only refill while you're nearby.
• A faint line can show at an area's edge if the neighbouring area is in the hands of a player without the mod.
• Ice refreezing and the Eternal Pyre are new in 1.1.0, and snow levelling, clear paths and fires melting snow are new in 1.2.0. All are lightly tested.
• Deleted Ice Sheets are found by replaying world generation. Where the terrain was changed a lot, a sheet can come back slightly off or not at all.
• Not yet tested alongside other mods that change terrain or the Deep North.

1.2.3

• Tracks made before you installed Fimbulvetr now fill back in. Ground walked, dug or levelled before the mod was there had no record of when its snow last refilled, so it only crept back while you stood next to it. Now the first time you come near such ground it gets two hours of catch-up at the calm rate, which is enough to refill even the deepest snow (OldTracksCatchUpMinutes, 120; 0 turns it off). Fresh tracks you make are left alone.
• New console command fimbul refill [metres] (30 m if you leave the number out): puts the snow around you straight back to its natural depth, including under rock overhangs and trees where it doesn't build up on its own. Hoe paths, ground under buildings and (with fires melting snow on) ground by fires stay clear. On a server, it refills the areas you look after, which is normally everything around you; it tells you if a nearby area belongs to another player.

1.2.2

• Refilled snow is saved as untouched ground again. Once a spot's snow is back to exactly what the world generated, it's handed back to the game as unmodified, so Deep North areas you've walked, dug or levelled no longer keep growing your world save and what the server sends to players. Nothing looks or plays differently.
• Fixed memory use creeping up over a long session: terrain areas you had left behind stayed in memory with their snow paths, and the mod's caches weren't cleared when you logged out or switched worlds (which could also stop sheets being put back in a second world).
• Lighter on each update: less garbage per tick, so fewer small stutters, and hoe paths are only saved when they change.
• New fimbul hitches on|off (LogHitches, off by default): logs frames that take much longer than usual with what the mod and the terrain did in them, to help track down stutters. fimbul now also shows its cache sizes.

1.2.0

• Snow levels itself out. Snow that walking and shovelling push up into banks settles back to its natural depth, and the snow smooths out with the ground around it, so trampled areas no longer grow spikes over time. New settings: SettleRate (3 cm/min) and Smoothing (0.3).
• Paths you make with the hoe, both the dirt path and the stone path, stay clear of snow, so you can lay out routes through the Deep North. Snow already on them melts away. Levelling, raising or digging over a path turns it back into ordinary ground. KeepPathsClear (on) and PathTools.
• Fixed steps and cracks in the snow along the edges between terrain areas. Snow depth is drawn as height, so a mismatch at an edge showed as a ledge or a gap. Edges are now matched after every terrain change and every few seconds, including against areas beyond Range that you're in charge of.
• Ground raised by snow always looks like snow, including the wall of a snow bank over a cliff edge, instead of a taller rock face that shrinks as you walk over it. Bare ground and lighting keep the vanilla look. It uses a copy of the vanilla terrain shader with only that rule changed (DirectX 11; on Vulkan the terrain stays vanilla). On by default, fimbul slopes off or SnowCoversSlopes to compare.
• Fires can keep snow away (off by default): fimbul firesnow on, or FiresMeltSnow in the config. Then snow melts and stays away within FireSnowReach (4 m) of any lit fire, torches included, and within PyreSnowRadius (20 m) of a lit Eternal Pyre. This replaces KeepHeatedGroundClear.
• Fixed ice sheets near an Eternal Pyre popping back in and then thawing again on every visit. Putting back deleted sheets also left an extra untouched sheet at each spot; that no longer happens, and the extra sheets already in your world are cleaned up as you pass by. A pyre now opens its whole area at once.

1.1.0

• Broken Ice Sheets freeze over again. Pieces refreeze one at a time, growing back from the ice that's left: slowly in clear weather, faster in snowfall, quickly in a blizzard. A sheet you break completely is no longer deleted, so it can freeze over too. Sheets the game already deleted, even before you installed the mod, are put back where world generation placed them, as open water that then refreezes. Time you spend away (or asleep) counts too, at the clear-weather pace, and is caught up as soon as you come back. Ice never refreezes within 30 m of a player while you watch, or around a boat or a creature. Docks and other buildings get frozen in like anything else; only heat keeps ice away.
• Heat keeps water open: no ice refreezes within 8 m of a lit fire: torches, campfires, braziers, hearths and other heat sources.
• A lit Eternal Pyre thaws all ice within 40 m and keeps it from coming back. Build one by your harbour. Thawed ice drops nothing.
• Fixed snow building up (and the ground turning back to snow texture) under floors laid directly on the ground, such as stone floors on hoed ground. Snow that already got under a floor melts away again.
• Fixed a step (seam) in the snow along the edges between terrain areas, where neighbouring areas had refilled by different amounts.
• The fimbul console command also shows ice sheets tracked, pieces open, refrozen and thawed.

1.0.1

• Fixed snow coming back invisible on ground you had dug, levelled or paved, and where tree felling had bared the ground. The snow was there (it slowed you down and blocked the hoe) but didn't show. Refilling snow now also wears away the dirt and paving marks, so it looks like natural snow again. Ground that already has invisible snow fixes itself the same way.

1.0.0

• First release.