LOD Server Support

Enables players with Voxy to see fully rendered terrain out to hundreds of chunks on multiplayer servers without needing to explore the world first. Also includes Far Players: players far beyond normal render distance appear in the LOD terrain with name tags, equipment, and mounts.

Try it live: join lod-server-support.modrinth.gg with Voxy and this mod installed. Supports Minecraft 26.2, 26.1, 1.21.11, 1.21.10, and 1.21.1.

Lss-Demo-Paper.mp4

Compatibility

Clients use the Fabric mod on every version; on 26.2, 26.1, and 1.21.1 a NeoForge client works as well. Supported servers:

Minecraft	Fabric	Paper / Purpur	Folia	NeoForge
26.2	✅	✅	✅ (experimental)	✅
26.1	✅	✅	✅ (experimental)	✅
1.21.11	✅	✅	✅ (experimental)	-
1.21.10	✅	✅	-	-
1.21.1	✅	✅	-	✅

On NeoForge (1.21.1) use Roxy to load the Fabric Voxy jar. Tested working with Roxy 0.2.0, Voxy 0.2.16-beta (the 1.21.11 build), Sodium 0.8.12, and Forgified Fabric API 0.116.15. If distant Voxy chunks do not show up, turn off environmental fog in your video settings.

The in-game settings page (Sodium's Video Settings → the LSS entry or tabs; on Fabric also ModMenu's Configure button) renders on both Sodium generations from v0.13.0: on Sodium 0.8+ it appears under LSS's own entry in the settings screen; on Sodium 0.6/0.7 (MC ≤1.21.10) it appears as LSS tabs beside Sodium's own. On NeoForge the page renders under LSS's own entry (native Sodium 0.8+), without the far-player render options, which NeoForge does not render yet.

Compatible with AntiXray, Moonrise, C2ME, ViaVersion/ViaBackwards, and most other mods. Can be run alongside Distant Horizons on the same server to support DH clients and Voxy clients simultaneously.

With Xaero's World Map 1.42.0 or newer installed on the client, downloaded LOD terrain is also written into the world map, so the map fills in far beyond vanilla render distance (multiplayer only — for single-player worldgen use Xaero WorldGen instead). This works even without Voxy: Xaero's Map plus this mod alone will download and map the server's terrain. The bridge is OFF by default (map writes are saved map data — chunks near you stay Xaero's own and Xaero redraws its tiles whenever you revisit an area, but distant LOD-drawn tiles, slightly simplified and matching any anti-x-ray masking the server applies, persist until you do): turn it on with the "Write LODs to Xaero's Map" toggle on the LSS Sodium options page, or enableXaeroMapBridge in lss-client-config.json. Tiles go to the map's surface layer; while the map is showing a cave layer (underground with auto cave mode, and the Nether by default) terrain that arrives is not written to the map and is not retried — revisiting the area (or /lss clearcache) backfills it — and the bridge follows Xaero's own "Load New Chunks" / "Update Chunks" switches. While the map is catching up on a big download, LOD delivery is paced to what the map can draw (enableXaeroMapBackpressure, default on), so the map fills in completely as it goes at a slightly slower rate — including brief full pauses of the LOD download (a few seconds) while the map itself is busy writing the terrain around you. On a server you had already explored before installing, run /lss clearcache once while connected to re-stream the terrain and backfill the map (a full re-download).

LOD Server Support is backwards and forwards compatible from v0.4.0 through the current version. Server operators can freely update to take advantage of improvements without breaking clients on older versions, and clients can update without breaking compatibility with older servers.

Far players. Players beyond your normal render distance are drawn as player models in the LOD terrain (Fabric client), lit as if under open sky (or at full brightness, mounts included, with the "Full Bright Far Players" option / farPlayersFullBright in lss-client-config.json), with their name tags (also drawn over players still in normal range once they are past the game's own name-tag distance) and, within about 80 blocks, their skin overlay layers (farther out the depth buffer cannot separate that thin shell from the body). Two limits worth knowing: players past the game's far plane (your render distance × 64 blocks; Iris shaders extend it) are not drawn at all, whatever the far-player render limit says; and with Iris shaders, packs whose Voxy integration keeps LOD depth out of the vanilla depth buffer (Complementary, for one) draw far players on top of LOD terrain instead of behind it.

Since v0.14.0 the client keys its LOD cache by world identity as well as server address, so proxy networks that move you between worlds behind one address no longer mix caches. On a lobby-first proxy (where you connect through a hub world before a game world) each game world may re-serve its LODs once on the first v0.14 visit; it warms fully after that. Set useWorldSubBuckets to false in the client config to keep the pre-v0.14 address-only cache (note: once a world sub-bucket has been adopted, turning it back off does not restore the old bucket).

Voxy Server Side is the same mod. Voxy Server Side clients are compatible with LOD Server Support servers and vice versa.

Installation

Install LOD Server Support on both the server (LOD Server Support Fabric mod, Paper plugin, or NeoForge mod) and every client (LOD Server Support Fabric mod + Voxy). Without LOD Server Support on both the connecting client and on the server it will not function.

Commands

Server (Fabric, NeoForge, and Paper)

• /lsslod stats - Show per-player transfer statistics
• /lsslod diag - Show detailed diagnostics (config, bandwidth, queue depths)
• /lsslod set <setting> <value> - Change common settings live, no restart needed
• /lsslod store status - Show LOD store status (state, hit/miss counters, size)
• /lsslod store backfill start|stop|status - Control the background pre-warm walk (not on Paper)
• /lsslod help - List all commands

Client (Fabric only)

• /lss clearcache - Clear the local column cache, forcing all chunks to be re-requested from the server
• /lss reset - Wipe this server's LODs (local cache and Voxy's stored data) and re-stream them fresh
• /lss reset voxy-force - Same, but for the case where another mod has redirected Voxy's storage (a replay mod, or any other storage override) and the ordinary reset therefore left Voxy's disk data alone. Shows both storage paths first and deletes nothing until you run /lss reset voxy-force confirm within 60 seconds on the same connection
• /lss diag - Show client-side diagnostics (connection, throughput, scan progress, request budget)

Configuration

Client cache identity. The client keeps its per-server download cache in per-world buckets automatically: each remote world is identified by the (already hashed) seed value every vanilla login carries, so a server that resets or rotates its map stops serving you stale "already downloaded" terrain, and your first session after upgrading adopts the existing cache warmly. useWorldSubBuckets: false in lss-client-config.json turns the per-world split off. For a server reachable at several addresses, cacheAddressAliases (for example [["play.example.com", "alt.example.com"]]) lets all of them share one cache so the world only downloads once — with Voxy installed this needs voxy-extra's LoD Mirror configured with the same list (first entries identical), and LSS applies the alias only when Voxy's own storage confirms it, falling back to the per-address cache otherwise. (voxy-extra is a Fabric mod, so on NeoForge with Voxy installed the alias never corroborates and each address keeps its own cache — the per-world split works on both loaders either way.) /lss diag shows the active cache key on its Cache: line.

Config files are generated during first run at config/lss-server-config.json on Fabric and NeoForge or plugins/LodServerSupport/lss-server-config.json on Paper.

Setting	Default	Description
enabled	true	Enable LOD distribution
requireServicePermission	false	Serve LOD data only to players who hold both the lss.use and vss.use permission nodes — everyone else is told LOD is unavailable and stops asking, with no session created; a mid-session revocation disconnects the LOD session within ~20 s and a re-grant (or turning the key back off) re-offers it automatically, no rejoin needed (current-protocol clients; a pre-0.10 legacy client keeps its session until it rejoins, where the handshake denies it). Works on all three platforms: Paper/Folia read Bukkit permissions natively; Fabric needs a permission provider implementing fabric-permissions-api (LuckPerms, most permission mods) — with no provider installed everyone is served and the log says so once (within ~10 s of arming); NeoForge registers native permission nodes. Both nodes default to on for everyone, so turning this key on by itself changes nothing; you then take a node away from whoever should not be served, and revoking either spelling is enough (LuckPerms: /lp group default permission set lss.use false, then grant it back to the groups you do want). Fail-open by design — a missing or broken permission backend serves everyone, so treat it as a distribution lever, not a security boundary (the data it gates is world terrain the client could also walk to). false skips the check entirely
lodDistanceChunks	512	Default max LOD distance in chunks. Per-world overrides go in lodDistanceChunksByWorld
lodDistanceChunksByWorld	{}	Per-world LOD distance. Keys are Bukkit world names on Paper (world_nether, or a Multiverse world like creative) and dimension ids on Fabric/NeoForge (minecraft:the_nether). Paper also matches a dimension id as fallback. Unlisted worlds keep lodDistanceChunks. Change live with /lsslod set lodDistanceChunks <world> <n> (<world> default clears an override). Current-protocol clients switch to a world's distance the moment they enter it; a pre-0.10 legacy client picks it up when it (re)joins
mbPerSecondLimitPerPlayer	25.0	Per-player bandwidth cap in MiB/s (decimals like 12.5 work), counted before compression
mbPerSecondLimitGlobal	75.0	Total bandwidth cap across all players in MiB/s, counted before compression
enableChunkGeneration	true	Generate missing chunks on demand, so players see terrain nobody has visited
generationConcurrencyLimitGlobal	40	Max chunks generating server-wide at once
generationConcurrencyLimitPerPlayer	40	Max concurrently generating chunks per player
maxConcurrentDiskReads	0	Max LOD disk reads running at once. 0 = auto (half the reader threads while the LOD store is on, all of them otherwise). See Server Performance Tuning
dirtyBroadcastIntervalSeconds	10	Interval for pushing dirty column notifications to clients. 0 disables the pushes entirely
farPlayers	"on"	Show distant players as player models in the LOD terrain. "opt-in" shows only players who opted in, "off" disables. A per-player exclude list is honored on every loader, as are the lss.farplayers.hidden / vss.farplayers.hidden permissions (players holding either are never shown; note a wildcard permission grant counts as holding them) and vanish: vanish plugins on Paper, Melius Vanish on Fabric and NeoForge. The hide permission only resolves through a permission provider (a fabric-permissions-api backend such as LuckPerms on Fabric, a permission handler mod on NeoForge); without one nobody is hidden. On Paper, players disguised with LibsDisguises are hidden as well.
farPlayersMaxDistanceBlocks	2048	Max distance in blocks at which far players are visible
lodYieldsToVanillaTransport	true	Pause LOD sending to a player while their connection is backed up, so vanilla packets always go first
enablePingBackstop	true	Cut a player's LOD rate when their ping spikes, keeping gameplay responsive on slow connections
enableSendPacing	true	Smooth LOD sending into small per-tick slices instead of bursts
enableRegionSummaries	true	Answer clients' region-summary requests at join/dimension entry: one small frame tells a returning client which areas are unchanged, so it skips re-checking terrain it already has instead of re-asking column by column. Needs a current-version client (older clients simply never ask)
lodStore	"on" (new installs)	Keeps a compressed copy of every served LOD column in <world>/lss-lod/ and serves repeat requests from it, which is far less CPU and disk work per chunk. The cost: it roughly doubles your world folder. Generated as "on" for brand-new servers; on an upgraded server whose config file doesn't have the key, it stays "off" until you enable it. See Server Performance Tuning
lodStoreBackfill	true	Pre-warms the store with a low-priority background walk of your existing world, so the first player to arrive already gets fast serves. Inert unless lodStore is on. Yields to players, pauses under load, resumes across restarts. Not available on Paper
lodStoreMaxMB	0	Size cap for the store. 0 = uncapped; set a value to bound it, and the oldest columns are evicted first
enableV16Compat	true	Serve legacy v0.4.x-v0.6.x clients through a built-in translation layer. false requires every client to match the server's protocol
enableV18Compat	true	Serve v0.7.x-v0.8.x clients natively, minus only the features their client predates. false drops them to the enableV16Compat fallback
enableV19Compat	true	Serve v0.9.x clients natively. false drops them to the enableV16Compat fallback
xrayObfuscation	"auto"	Anti-xray masking for LOD data. "auto" mirrors your anti-xray engine's own hidden-block list and height cutoff whenever one is detected (Paper's built-in, per world; the DrexHD AntiXray mod on Fabric). "on" forces masking, "off" disables it, in which case LOD data carries real ore locations even on anti-xray servers
xrayHiddenBlocks / xrayMaxBlockHeight	ore list / 64	Fallback list and Y cutoff, used only when no engine settings can be adopted

Server Performance Tuning

Turn the LOD store on. "lodStore": "on" is the single biggest CPU performance win available, it caches the preprocessed LOD data to disk with the drawback of roughly doubling (+70%) the size of your world directory.

When the LOD store is enabled a backfill task will populate it. Maximum CPU savings are only achieved after the store is populated. Check the progress of the task with /lsslod store backfill status. If your world is much larger than the area players commonly visit you can save on disk space by disabling the backfill task with the "lodStoreBackfill": false config.

Use the bandwidth and generation limiters to limit CPU. LOD Server Support's CPU cost is essentially how many columns per second it serves plus how many chunks it generates, and these configs cap exactly that:

• mbPerSecondLimitPerPlayer / mbPerSecondLimitGlobal bound the chunk serve rate. They count uncompressed bytes on purpose so compression doesn't quietly raise the real ceiling. The actual max network utilization will be approximately 1/8th of these limits.
• generationConcurrencyLimitGlobal / generationConcurrencyLimitPerPlayer bound new chunk generation, by far the most expensive thing LOD Server Support can trigger. On a server exploring fresh terrain this dominates, and lowering it is the single biggest saving. enableChunkGeneration: false removes it entirely.
• maxConcurrentDiskReads bounds how many LOD disk reads run at once, so LOD traffic can't monopolize disk I/O that vanilla chunk loading needs. The 0 auto default is right for most servers; lower it to 1 or 2 if gameplay chunk loading stutters while LODs stream, raise it if LOD loading feels slow on fast NVMe storage.

Disable LOD store resweep on Paper. "lodStoreResweepSeconds": 0 This will reduce CPU utilization at a slight cost to correctness, on Paper its possible to miss chunk updates so old LODs could be served.

Redistribution

This mod is MIT-licensed, redistribution with attribution is welcome, and modpacks can reference the official Modrinth project directly. Per Modrinth's reupload policy: XANTHA via Voxy Server Side has the copyright holder's explicit permission to distribute this mod, and derivatives of it, on Modrinth.