Changelog

0.3.0 - 2026-10-14

• Max Simulation Distance: the server's draw-distance ceiling as a setting. "Draw distance" in the client menu is Valheim 1.0's SimulationDistance, and it is negotiated - a client asks, the server answers RPC_RequestValidSimulationDistance with min(request, its own). The ceiling is therefore the server's own graphics setting, which on a dedicated server comes from PlayerPrefs: HKCU for whatever account the service runs as.

  That is a bad place to keep a server setting. A service under a virtual account (NT SERVICE\<name>, which is what nssm creates) has no profile directory, so there may be no mounted hive to read: a value written there is never seen. Three attempts to raise the ceiling by hand left every capture still reporting asked 6, capped by the server at the compiled default of 2, with nothing to say why.

  The handler is now answered directly from this setting, so the server's own pref stops mattering. -1 leaves it to vanilla. Levels as the slider shows them: 0 Low (square 224 m), 1 Medium (288), 2 Classic (square 288, the game default), 3 High (352), 4 Very High (416), 5 Ultra (480), 6 Extreme (544); reach is (level + 2.5) x 64 m.

  It is still a minimum, so a client asking for less than the ceiling keeps its own choice - a slow machine lowering its draw distance is never overridden into loading more than it asked for. And it still caps, which is the point: a client's simulation distance is a cost the server pays, since it sends each peer the objects in that peer's active area. Raise it a step at a time.

0.2.2 - 2026-10-05

• A client being sent the world is no longer mistaken for a struggling one. The detector counts gaps in the updates a client sends, and a client loading a region stops sending for stretches at a time. To the server that looks exactly like a machine failing to keep up, and it was counted: a capture on 2026-10-04 had the admin's own login produce 68 stalls in six minutes - 11.3 a minute against a threshold of 6 - which flagged the fastest machine on the server as the one to steer work away from, during the one stretch when it was not even playing yet. Single gaps over five seconds were already ignored for this reason; what that missed is that loading is mostly made of the shorter gaps, dozens of them.

  A grace period after joining was the obvious fix and the wrong one: that same login streamed for five minutes, so a window long enough to cover it would be long enough to miss a genuinely bad machine, and would still not cover a portal into unexplored ground. So the server measures the thing itself - how fast each peer's ZDO set is still being filled in - and while that is climbing quickly, the client's silences are treated as the cost of receiving rather than as evidence about its hardware. It lasts exactly as long as the streaming does, whether that is twenty seconds through a portal or five minutes at login.

  Loading is not a verdict either way: it neither flags a client nor counts towards the clean run that clears a flag. Where the per-peer counts cannot be read, this reports nobody streaming, so the detector behaves as it did before rather than failing.

0.2.1

• An object goes to the player standing on it when its owner is nowhere near. Greg's rule, and it fixes the case people actually feel: shoving a boar toward its pen. Every push travels to whoever owns the boar and the corrected position comes back, so the animal lurches - and the owner may be a hundred metres away with no interest in it. The same goes for opening somebody's chest, or anything you are standing over.

  Take at 2 m, give up only at 5 m. That gap is what stops an object flitting between two people: once the near player owns it they are at zero distance, so the rule cannot fire again until somebody else is nearer than 2 m while they are further than 5. It settles by construction rather than by a cooldown.

  Nothing to do with anyone's machine being slow, unlike everything else here - the object is simply in the wrong hands. Distances come from each player's character ZDO, which syncs every 67 ms since the pacing change, rather than the zone-grained peer reference position.

  The active-area predicate is only told an object's position and its owner, never which player is being offered it, so a small patch on ReleaseNearbyZDOS records whose pass is running. Without it the rule could tell that the owner was far away but not that this player was close, and vanilla would have handed the object to whichever peer happened to be iterating.

• The guards now apply to every rule, not just the yield one. The open-container and combat checks sat inside the yield branch, so the rule above would have bypassed both - handing away a chest somebody had open, or a creature mid-fight.

• Ownership is frozen near fighting. The attacker rule already refused to move anything living, because a creature's target, path and alert timers are not all replicated and the new owner restarts its AI from whatever the ZDO holds - which in play is a boss that stops attacking. The yield rule had no such guard, which was an inconsistency rather than a decision: it works through a predicate that is handed a position and an owner and never learns which object it is being asked about, so it cannot tell a troll from a fence post.

  Greg reported exactly that symptom after a Gerhaffa fight, and it does not need the yielded player to have arrived first - ownership moves whenever an owner leaves an object's active area, so simply walking through was enough to acquire the boss and have it taken away again.

  Since the object cannot be identified, the guard is spatial: every damage RPC the server relays marks a place and a time, and ownership stops moving within 40 m of recent blows until 15 quiet seconds have passed. Coarse - it protects the fence posts in the fight too - but it errs the safe way, and a fight is the one moment when rebalancing has nothing to offer.

0.2.0

• Every player is sent their world update each cycle, instead of one player per frame. Vanilla serves exactly one peer per server frame, so each player hears from the server every (players + 1) frames. Measured on bahnsheim at its 30 Hz cap, and the model is exact at both ends: one player (1+1) x 33.3 = 67 ms, measured 67; five players (5+1) x 33.3 = 200 ms, measured 199, 200, 201 and 204.

  Five updates a second, with four other people in the world. Everything a player does not own - where everyone else is, what their creatures are doing, the ship they are standing on - arrives at that rate and is interpolated in between. It is the one cost that grows with the size of the group, and it is invisible to every other measurement: in that same capture the server held a perfect 33.3 ms tick on 17% of one core and stalled 3 times in 1800 seconds.

  The 50 ms gate in the vanilla loop never signifies, because m_sendTimer keeps accumulating during the serving frames and is always long past 0.05 by the end of a cycle. But it reads like an intended 20 updates a second, which the per-frame loop quietly turns into 20/N. This restores that intent: Updates Per Second, default 20, no longer divided by the player count.

  Safe because the real flow control is untouched. SendZDOs refuses outright when the socket's send queue is backed up and caps each package at what is left of 10 KB, so the socket's capacity still decides and the gain is self-limiting rather than a flood. On bahnsheim that queue sits at a median 3.7 KB against a refusal threshold near 8 KB, so expect real improvement rather than a clean six times.

0.1.4

• A player being hit is no longer treated like a tree. The attacker rule skipped creatures by looking for BaseAI, and a player does not have one - so when something hit a player, the damage RPC named that player's own ZDO and their character was handed to whoever swung. The receiving client then found it owned a Player that was not its local one and did what vanilla does in Player.FixedUpdate: logged "Destroying old local player" and destroyed it. The player's screen went black and they had to rejoin. The test is now Character, which every creature has too, so nothing living is ever moved.

• A chest stays with the player who has it open. Vanilla's container code assumes whoever has the window open owns the ZDO - OnContainerChanged saves only if (IsOwner()), and Load() repaints the panel whenever the data revision moves. Steering a yielded player's chest away mid-session broke both: the stack they dragged out reappeared in the chest a moment later while the one they took sat in their inventory. Nothing was ever duplicated and closing the chest cleared it, but it looked alarming. Open containers are now held with their user, the way a ship is held with its captain. The open request names the chest - it is routed through the server, and only travels at all when somebody else owns it - and the container's own InUse flag says when to let go.

0.1.3

• A tree, rock or ore vein now goes to whoever is hitting it. Vanilla never does this - TreeBase, TreeLog, Destructible and MineRock5 all open their damage handler with if (!m_nview.IsOwner()) return; and nothing anywhere calls ClaimOwnership - so the machine that loaded a tree keeps it and every swing anyone else makes travels there and back, for that tree and the next one. A chopping session is hundreds of interactions against a handful of objects, which makes this the commonest way a group feels somebody else's frame time.

  Resources only. A creature carries live AI state that is not all replicated, so moving one mid-fight can make it re-acquire its target or re-path - a real hitch in the least welcome moment, left alone until it can be measured rather than reasoned about.

  Three details that matter: the transfer waits 0.4s so the swing that triggered it lands first (the old owner's handler checks ownership, and changing it immediately drops that hit); a dwell time stops two players bouncing one tree between them; and it never hands an object to a player work is being steered away from, which would only churn.

• Ship prefabs are found in the right registry. The scan read ZNetScene.m_prefabs, the list serialised with the scene, and found the five vanilla hulls and none of TheGreatestShips'. Mods register into m_namedPrefabs, which is what GetPrefab reads. Now 13 hulls including every DM_* ship.

0.1.2

• The yield list is switched off with the mod. IsYielding did not check Enabled, so with the mod turned off but names still configured it answered yes about a rule that was not in force. The ship pass consults it, so this was a real bug rather than only a display one.
• A small public API, SpreadTheLoadApi, so DiagnoseServerLag can grey the rows of players work is being steered away from. This mod stays server-only and gains no client half; DSL's server half reads it and sends the answer down with its own report.

0.1.1

Both fixes come from the first run on a real server.

• The "NOT WORKING" alarm was a false positive. It fired on a healthy server with no conflicting mod installed. IsInPeerActiveArea is only reached from the second half of (!zdo.HasOwner() || !IsInPeerActiveArea(...)), so an ownerless object short-circuits past it and an object owned by the peer being processed takes the other branch entirely. It is consulted only when one player's active area contains an object somebody else owns - which never happens while everyone is off in their own corner. Silence now only corroborates the Harmony inspection instead of accusing on its own.
• Modded ships were missed. The prefab scan ran once at startup and found the five vanilla hulls and none of TheGreatestShips', because mods register their prefabs after ZNetScene exists. It now re-scans whenever the prefab list grows, which self-corrects however late a mod registers.

0.1.0

• First build. Server-side only; nothing to install on clients.
• Steers object ownership away from named players. Valheim simulates each object on the one machine that owns it, gives ownership to whoever was in range first, and never rebalances - so one struggling client's frame time becomes everybody else's input delay. This hands those objects to another player who is already in range, and hands back the ones already held. Anything only the named player is near stays theirs, so nothing is ever left unsimulated.
• Players are identified by network id, not by character name. A name is used once to find somebody; their id is remembered in SpreadTheLoad-known-ids.txt and used from then on, so the setting survives them playing a different character.
• Optionally finds struggling machines by itself, off by default. Not by ping or connection quality - the machine this was written for had a 24 ms ping and ran at 16 fps - but by timing the gaps between the updates each client sends. Rate saturates around 20 Hz and tells you nothing; a 479 ms hole in the stream tells you plenty. Clearing a flag is deliberately harder than earning one, and the last healthy player is never flagged.
• Ships follow the helm. Vanilla only reassigns a ship when its owner is not aboard, and then picks an arbitrary passenger instead of the captain, while steering is batched to the owner every 0.2s and the physics runs only there - so the person steering often waits a quarter second for every turn. Ship prefabs are found by component, so modded hulls are covered without a list. Whether a yielding player keeps the helm is a setting, defaulting to yes.
• Config changes take effect without a restart. BepInEx keeps the value parsed at startup, so without a file watcher an edited setting would do nothing until the process restarted - which on a dedicated server means disconnecting everybody to change who is being steered away from. The file is watched and reloaded, and every setting is read fresh each pass, so a change lands within a second.
• Says so when it is not working. ValheimPerformanceOptimizations replaces the vanilla method this mod works through, which would otherwise leave it silently inert. It checks both by asking Harmony who else patched that method and by noticing its own decision was never consulted while players were connected.