This page explains the configuration files that control Flan's Mod Ultimate 2.0. It is written for players, server owners, and modpack makers who want to tune the mod without editing Java code.

For content-pack .txt parameters such as gun, bullet, armor, and grenade fields, see Config Reference. For bulk edits applied through JSON groups, see Category System.

After the mod starts once, these files are created in the Minecraft config folder:

On a dedicated server, the same paths are inside the server folder. For multiplayer, keep content packs and category files matched between server and clients unless the change is purely visual.

• Stop the game or server before changing content loading settings or category files.
• Common and client TOML settings may be picked up by Forge while running, but a restart is the safest way to test changes.
• Content loading settings and category JSON files are loaded during startup. Restart after editing them.
• In TOML files, booleans are true or false, numbers are not quoted, and strings/enums are quoted when the generated file uses quotes.
• In .properties files, use key=value.
• In JSON category files, use valid JSON. Comments are not allowed.

Most settings do not need the TOML files at all. Flan's Mod adds an options screen, reachable from:

• the Flan's Mod Options... button in the vanilla options screen, just above its Done button. optionsButtonPlacement can move this button to the pause menu, show it in both menus, or leave it out;
• the Config button next to Flan's Mod Ultimate in the Mods list.

The menu button opens the quick screen: the HUD, weapon visuals, rendering and gameplay settings worth changing mid-game, plus a few server toggles. Its All Settings... button, and the Config button of the Mods list, open a chooser between the two config files:

All Settings -> Client Settings  -> every entry of flansmodultimate-client.toml
             -> Common Settings  -> every entry of flansmodultimate-common.toml

Both lists are grouped by the sections of the file itself, and each row uses the comment of that setting as its tooltip, so the screen says the same thing the file does. Settings that are free text or lists, such as the penetrable block list or the default engine names, are not shown; those stay in the config file.

They take effect as soon as they are changed and are written straight to flansmodultimate-client.toml, so they survive the session. Sliders are the exception: they change the value while dragged and write the file once the screen closes, so a drag does not rewrite the config a hundred times. Switching uncensored content on or off reloads client resources, exactly as editing the file would.

The driveable HUD shows speed in km/h by default. Plane vertical speed has a separate driveableVerticalSpeedUnit setting and defaults to m/s; both units can be changed independently in the client options or TOML file.

Who owns them depends on where you are:

• Outside a world, the common screen edits this installation's own flansmodultimate-common.toml, which is the config a world hosted from here uses.
• In a world, the settings belong to the server. The screen shows the values the server reports, not the local file, and a change is a request the server checks. An operator, or the owner of a single player world, may make it; for everyone else the rows are shown greyed out. The footer of the screen says which of these applies.

An accepted change is saved to the server's flansmodultimate-common.toml and sent to every connected client at once, without a restart. The server always answers with the values that ended up in force, so a refused change, or one another operator made at the same time, snaps the row back instead of leaving a value the server never accepted on screen. Settings whose comment says a restart is required still need one to take effect, however they were changed.

The quick screen keeps these within reach without opening the full list: disableCrosshairForGuns, explosionBreakBlocks, flanExplosionsDropBlocks, driveableCollisionsBreakBlocks, shootablesCanBreakGlass, playerAimPose, entityAimPose, driveableTrackingRange and flanNpcTrackingRange (with Wolff's NPCs installed). A separate Server Sound Ranges section lists every setting of the Sound Settings below, overridePackSoundRanges included. Its range sliders move by one block up to 1024 blocks; larger values can still be set in the config file.

Hovering a row shows the setting's name and current value above its description; server settings a player may not change are greyed out, and their tooltip says so.

File: config/flansmodultimate-common.toml

These settings affect gameplay. In multiplayer, clients receive the server's common config while connected, so changing a client's local common file will not override a server.

The three default*Engine settings accept an engine's item shortname or item ID, with or without its namespace, for example advCPU, flansmod:advCPU, or otherpack:advCPU. They only affect automatic engine assignment; an engine already saved on a driveable is kept when it is valid.

For a vehicle, plane, or mecha with no valid saved engine, the mod selects an engine in this order:

1. The driveable content file's Engine parameter.
2. The matching global defaultVehicleEngine, defaultPlaneEngine, or defaultMechaEngine setting.
3. The fastest eligible engine from the driveable's own content pack.
4. The eligible official-pack engine closest to EngineSpeed 1, when official packs are loaded.
5. The eligible engine from any loaded content pack closest to EngineSpeed 1.

Empty, missing, invalid, or incompatible values fall through to the next rule. An eligible default engine must be an ENGINE part, set CanBeDefaultEngine true, not use RF power, and include the relevant driveable kind in WorksWith.

Operators can also change both in game with /teams bltss <min> <divisor>; see Commands.

Driveable and Flan NPC tracking settings below apply live, including existing entities. They are available in the quick menu to the single-player owner or server operators; other players can view the server values. Ranges are blocks, not chunk counts. Minecraft still applies server view distance and tracking scaling; passengers can raise their vehicle's effective tracking range under Minecraft's normal passenger rule.

Flan vehicle and AA-gun NPC models automatically use the NPC settings. Operators can opt ordinary Custom NPC soldiers in with /flansnpcdistance <targets> true, and remove that explicit opt-in with /flansnpcdistance <targets> false. The flag is saved with the NPC and synchronized to clients. Removing it does not exclude a Flan model. Ordinary Custom NPCs retain their original settings unless opted in.

These values control when the server sends the entity to clients. They are read while entity types are registered, so restart the game or server after changing them.

Values above 1.0 increase damage. Values below 1.0 reduce damage.

DamageReduction and OtherDefence / OtherDefense keep their legacy behavior even when forceDefenseAsModernArmor is enabled.

For broad balancing, start with global multipliers. For per-weapon tuning, use the Category System or edit the weapon's content-pack file.

These settings affect bullets, grenades, shells, rockets, and other shootable items.

The new damage-system reference settings are advanced balance controls. Change them when you want to rebalance a whole pack around projectile mass or explosive mass, not when you only want to adjust one bullet or grenade.

Particle range settings affect how far the server sends visual-effect packets. Larger values can increase network and client particle load on busy servers.

Every range of 16 blocks or more also sets loudness: the sound fades out linearly at that range. Shorter ranges play at full volume nearby and only limit who hears the sound, as in 1.7.10. The single soundRange setting of earlier versions was split into the reload, gun action, melee and grenade throw ranges; an old soundRange line is ignored.

Larger values make sounds carry farther and may increase how much sound traffic is sent on busy servers. The configured range also sets the packet delivery radius, including values below 16 blocks.

Each blocks entry uses this format:

blocks = [
    "minecraft:stone; 3.0; false",
    "minecraft:glass; 0.3; true"
]

The format is:

namespace:block; hardness; breaksOnPenetration

hardness is a decimal number. breaksOnPenetration is true if the block should break when penetrated, or false if it should remain.

Example supply block setup:

digitalAmmoSupplyBlocks = [
    "minecraft:iron_block",
    "minecraft:barrel"
]
digitalAmmoSupplyAmount = 250

Use namespaced block IDs such as minecraft:barrel or yourmod:ammo_crate.

Each dimension has its own gravity and drag factor. An unlisted dimension uses 1, including the Overworld, Nether and End. For example, set dimensionGravityFactors = ["space:moon=0.17"] and dimensionDragFactors = ["space:moon=0.05"] in the common TOML. At 1, authored physics is unchanged; 0 removes the relevant force. Per-tick velocity retention r becomes r^dragFactor; derived drag forces are multiplied directly. These settings affect Flan's physics, not vanilla entities or terrain friction.

Operators can inspect the current dimension with /flansphysics, or inspect a named dimension with /flansphysics gravity <dimension> and /flansphysics drag <dimension>. Set an override with /flansphysics gravity <dimension> <factor> or /flansphysics drag <dimension> <factor>. Replace the factor with reset to remove its override. Command changes are saved to the common TOML and synced to clients immediately.

The mod treats one block as one metre and twenty ticks as one second, so km/h becomes blocks per tick as kmh / 72, then multiplied by the scale belonging to that class of driveable:

effectiveBlocksPerTick = (realMaxSpeedKmh / 72) * classSpeedScale

1.0 runs a class at its full real-world speed; 0.5 runs it at half speed. Only speeds are scaled: mass, engine power, thrust, wing area, slope, and draft are never scaled. Driveables that declare no real-world parameters are unaffected at any setting, and mechas, which have no real-world profile of their own, are never scaled.

Every real-world speed follows the class scale together — top speed, reverse speed, climb rate, the derived stall reference speed and the wheel look-ahead — so a slowed aircraft still takes off and stalls at sensible fractions of its own reduced top speed rather than becoming unflyable.

The two hard caps are a different mechanism. A scale changes what a driveable's top speed is; a cap refuses to let anything travel faster than a fixed figure, whichever path produced its velocity, so it also covers legacy driveables, helicopters, VTOL, and six-DOF craft. It scales the whole velocity vector, so the direction of travel is preserved, and it does nothing at all while a driveable is slower than the ceiling.

forceLegacyPlanePhysics and forceLegacyVehiclePhysics take precedence over every other movement setting in this section. They are migration and compatibility switches: content definitions and their Real* data are left untouched, but the selected class runs its legacy movement path globally. Damage and health settings are not movement physics and remain active.

These settings are synchronized to clients with the rest of the common config, so item tooltips on a server show the server's effective values. See Realistic Vehicle Physics for the full parameter list.

Driveables normally run on Fuel Can parts, or on Forge Energy when their engine sets UseRFPower. This section adds liquid fuel: any container that reports Forge's fluid handler capability — buckets included — can be dropped into a driveable's fuel or cargo slot and will be emptied into the tank.

Each line names a fluid by registry id and the fuel one bucket of it yields. A trailing * on the fluid path matches everything starting with it, which covers a mod's grade and heat variants in a single line. The first matching line wins, so a specific fluid placed above a wildcard overrides it. Anything not listed — water and lava included — is never accepted as fuel.

The defaults are:

fluidFuels = ["buildcraftenergy:oil*; 1000", "buildcraftenergy:fuel*; 2000"]

For scale, the Parts pack Fuel Can holds 1000 fuel and vehicle tanks are usually 1000 to 6000, so a bucket of crude oil is worth one can and a bucket of refined fuel two — the same ratio Flan's Mod used on 1.7.10.

No mod is required for this and none is depended on: fluids are matched by registry id, so a server running BuildCraft gets its oil and fuel out of the box, and any other mod's liquid fuel can be added or retuned with a line of config. Fuel is taken a bucket at a time and only when the tank has room for the whole bucket, and the emptied container is left in the slot it came from.

These settings calibrate optional physical vehicle armour and normalized health. Vehicles that do not opt into those definition features remain unaffected.

All of these values are server-authoritative and synchronized to clients. The blast resistance is a gameplay calibration rather than a material-science constant. See Vehicle Armour and Damage for the content-pack parameters and calculation flow.

These settings decide what is sent to players whose client draws far terrain with Distant Horizons and asks for it. Players without it are sent nothing. See Distant Horizons Integration.

File: config/flansmodultimate-client.toml

These settings only affect the local client. They do not change server rules.

Legacy multipart models receive automatic rendering optimizations without changes to their model classes or an additional config option. The renderer reuses local transforms for leaf parts and retains geometry/face-normal data while transformed vertices remain unchanged. Animated transforms and bone-group changes are still evaluated. Polygon caps also submit fewer duplicate vertices while keeping the same triangles; incomplete legacy normal lists retain their original submission order. These optimizations reduce CPU work and vertex traffic, but the FPS benefit depends on the scene and hardware.

Distant driveable impostor views are copied directly into their texture atlas on the GPU. A view is generated at the start of the frame after it is first needed, before the world is drawn, so fog, the camera's lighting and shader packs cannot affect it. Captures reuse a vertex buffer and share measured bounds between cached paint variants of the same model and vehicle type. Vehicles already displayed as impostors skip detailed per-frame render-state preparation; their animation history continues updating for the return to exact geometry. These changes target capture hitches and distant crowds without adding settings or changing model classes.

loadAllModelsInCache can use a lot of RAM and make resource reloads much slower when many content packs are installed.

These local pitch multipliers apply when a vehicle or plane definition does not specify its own engine pitch values. The loop interpolates between the 0%, 50%, and 100% throttle points. A definition's EngineSoundPitchRange instead gives a linear curve from its pitch base to base plus range.

These place the two blocks of the vehicle HUD, which AA guns and deployed guns share. They are in GUI pixels and also appear in the HUD section of the in-game options screen, where dragging a slider moves the HUD straight away.

The quick menu offers separate driveableRenderDistanceMultiplier and flanNpcRenderDistanceMultiplier controls. Both default to 1.0 and accept 0.25 to 4.0. The NPC control requires the NPC module.

The distance is the average of the entity collision bounding box's width, height and depth, multiplied by 64, Minecraft's view scale, and the selected multiplier. Minecraft's view scale still includes its Entity Distance setting and effective chunk render distance. Larger collision boxes therefore keep proportionally larger distances. These controls do not change collision geometry or frustum bounds. Malformed numeric values are rejected or corrected to defaults.

Full entities remain limited by server tracking and loaded chunks. The multiplier tooltip shows the server tracking setting; an increased multiplier cannot bypass server limits. NPCs have no Distant Horizons contact proxies. The separate controls for bullets, grenades, deployed guns and AA guns remain independent.

The main options screen's Rendering section has separate Model LOD and Impostors sliders. GPU Model Caching occupies the first row, Model LOD and Impostors the second, and the driveable and Flan NPC render distance sliders the third. Their handles snap to marked stops: Off, Ultra Quality, Quality, Balanced, Performance, Aggressive, Extreme, and Max FPS. Quality matches the default config. Existing saved settings are preserved. Hovering over either slider shows the exact client config values for its selected stop. Choosing a preset writes those values when the screen closes; no new preset field is added to the file. On opening the screen, Custom indicates that advanced values do not match any preset. This last stop leaves the current config values unchanged.

Model-detail presets adjust part-size culling and supported tank-track LOD. Off sets their thresholds to zero while leaving generated impostors available. Impostor presets adjust the projected-size threshold and minimum/maximum distances; Off sets the pixel and maximum-distance thresholds to zero while leaving model LOD available. Both sliders enable the shared enableDriveableLod master switch when changed. If it was previously off, the other feature stays off until its own slider is changed. The advanced groundVehicleLodDistanceFactor is shared by both features, so neither slider changes it. Impostor presets other than Off use the default 64-pixel resolution, 8 base yaw views and quality multiplier of 2 (128 pixels/32 yaw views effective). They leave the impostor cache-size limit unchanged. Actual transitions still depend on model size, screen size, whether a view has been captured, and the image-quality limit; Max FPS is an aggressive preset, not a guaranteed FPS gain.

enableGpuModelCache is an experimental client option, enabled by default. Set it to false in this section of config/flansmodultimate-client.toml, or use the GPU Model Cache toggle under Rendering on the main Flan's options screen. The toggle saves and applies immediately. It caches rigid vehicle and gun model geometry on the GPU. Up to 768 geometries sharing at most 96 transform entries fit in each draw, while animation, tint, overlay and lighting are updated every frame. This retains the selected geometry's detail; existing distance LOD settings continue to apply independently.

Eligible rigid parts hidden by projected-size culling keep their cached mesh slots; the renderer draws only the visible index ranges. This avoids new mesh uploads when only part visibility changes. Entirely hidden batches skip upload and draw. Use /flansrenderstats start and /flansrenderstats stop to inspect cache hits, uploads, evictions, draws and culling; Rendering Performance explains the counters and measurement limits.

gpuModelCacheMegabytes caps the video memory the cache keeps for vertex buffers. 0 (Automatic on the options screen) uses a sixteenth of the dedicated video memory reported by the driver, from 128 to 512 MiB, or 128 MiB when the driver does not report it. If meshes drawn in the last two frames keep being evicted for two consecutive 2-second windows, Automatic grows by a quarter, up to an eighth of video memory (at most 1 GiB) and only while 512 MiB of video memory stays free. It never shrinks on its own; resource reload, disconnect or toggling the cache return it to the starting value. A manual value is never grown. The option's tooltip shows the value Automatic selects on the current computer and the video memory it is based on. Buffers are created only as models are drawn, so the cap limits memory rather than reserving it. The cache must hold every distinct model drawn in a frame; raise the cap if /flansrenderstats reports evictions of meshes drawn in the last two frames. A changed value applies without a restart, evicting meshes beyond a lower cap. Uploads are limited to 2 MiB per client tick. Resource reload, disconnect and toggling the option release cached buffers. Glowing or bone-deformed geometry, GUI previews, glint, thermal masks, sorted transparency, Fabulous graphics, OptiFine and an active Oculus or Iris shader pack use the standard path. With Oculus or Iris installed but shaders turned off, the cache stays available. See Rendering Performance for how shader packs are handled. Translucent models need enableFastTranslucentRendering enabled to use the cache. Armor and other renderers are currently unchanged.

Compare frame times after looking around to warm the cache. This is intended to reduce CPU vertex processing for detailed models; it cannot eliminate GPU fill-rate bottlenecks. Extra draw calls, slightly different normal rounding and render ordering may cause slower frame times or visual differences on some setups. Set enableGpuModelCache = false to restore the standard path without a restart.

The renderer reuses submission buffers and geometry cache probes after warm-up. Normal internally owned geometry uses revision checks instead of scanning every polygon on every draw. Geometry exposed through legacy mutable APIs retains conservative validation. See Rendering Performance for implementation details, compatibility limits and the development benchmark.

Track geometry LOD replaces each supported link with a textured six-face envelope. At up to eight screen pixels per link by default, one longer envelope represents two links; at up to four pixels, it represents four. The original per-link angle simulation continues so links resume their correct animation when closer. Damage still hides each whole track side. The distant envelope is an approximation. Selection includes model scaling and track-path offsets, stays at full detail nearby (at least 32 blocks), and uses 25% size hysteresis to avoid flickering between detail levels. Previews, the locally controlled vehicle, and unsupported geometry (including glowing, bone-deformed, hidden, child or custom renderer parts) retain full detail. Wheels remain unchanged. No edits to legacy model classes are needed.

Whole-model detail reduction smoothly raises the part-size threshold over 24�80 size-scaled blocks. This applies to eligible small parts throughout the model, including hull and turret details, even if damage or a full impostor cache prevents using a billboard. It omits small parts rather than rebuilding their meshes. Menu previews and the locally controlled vehicle do not receive this stronger reduction.

The distance scale is max(1, modelRadius / 3), with no upper cap. Small land vehicles additionally use groundVehicleLodDistanceFactor; that discount fades out between radii of 6 and 12 blocks. For example, a 3-block-radius tank uses base impostor distances of 32/64 blocks, while a 60-block-radius ship uses 1280/2560. These are eligibility distances: the requested view must be captured, and its projected size must fit the quality limit. At the effective default resolution of 128 pixels, a new impostor is limited to about 143 pixels across, with hysteresis on the return transition. Zooming in can therefore restore geometry.

Default impostor captures use 128 x 128 pixels, 32 yaw angles and nine pitch angles spanning -90 to +90 degrees, including directly above and below. The closest horizontal view is at most 5.625 degrees away; the closest elevation is at most 11.25 degrees away. Billboard orientation follows the direction from the model center to the camera and retains the model's bank angle, including pitched and rolled aircraft. Turning the camera without moving it does not select a different side of the model.

Captures remain limited to one view per client tick and always use full geometry. Until the requested view is ready, the exact model remains visible. Atlas pages hold four yaw views and three elevations each and are allocated only when needed. At default quality, each page uses 0.75 MiB of GPU storage plus similar native image storage. One entry starts with one page; visiting every direction can grow it to 24 pages (18 MiB each for GPU and native storage). Filling all views in all 32 default entries would use 576 MiB of each, so higher angular coverage can still increase memory use after extensive viewing. Resource reload or changes to capture quality clear these pages. Set driveableImpostorQualityMultiplier to 1 to use the configured resolution/view counts directly; the smaller image-quality limit may delay impostor transitions. Mechas, damaged vehicles and the locally controlled vehicle still do not use neutral-pose impostors.

These settings only affect client-side rendering. On multiplayer, the server still controls whether the entity is tracked and synced through the common tracking range.

Every Flan's Mod particle effect has its own natural drawing distance. Ordinary particles such as smoke, sparks and impact dust use 128 blocks. Larger effects reach further: an explosion's afterglow, dust skirt, rising column and mushroom cap are drawn from 16 blocks per block of crater radius, up to 256 blocks, so a heavy charge's column stays visible across the battlefield. These distances are not settings; particleDistanceScale scales all of them together.

particleDistanceScale and fullParticleDensityShare replace the older particleRenderDistance and fullParticleDensityDistance block values. An old client config drops those two entries and starts from the new defaults.

Allowed mouse button values:

MOUSE_LEFT
MOUSE_RIGHT
MOUSE_MIDDLE
MOUSE_4
MOUSE_5

Each player chooses for themselves what a reload does with the ammo it takes out of the gun. The client sends these preferences to the server when joining and whenever they change, so they apply to reloads the player requests and to automatic reloads alike.

Players on a vanilla or outdated client never announce a preference, so the server's own settings decide for them.

Players and humanoid mobs hold guns and shields with each arm posed on its own:

ENFORCED keeps every held gun raised this way. DYNAMIC, the default, lowers a gun until it is fired or aimed through the sights, and keeps it up for a second after the last shot. When only one of two guns is active, only its own arm comes up.

Your choice is sent to the server, which relays it to every player who can see you, so they see your arms the way you chose. The server's hit detection follows the same pose, so a lowered arm is hit where it is drawn. Mobs follow entityAimPose instead: mob renderers that reset their own arm poses every frame, such as vanilla skeletons, keep their own animation.

These options choose whether certain item types use translucent rendering by default. If a content file explicitly has TranslucentRendering true, it remains translucent regardless of these defaults.

Disable a translucent default if a large pack has rendering issues or if you want a more opaque-looking item type by default.

These options choose whether certain item types use face culling by default. Disable one only for content that needs double-sided model faces. Content files with DisableCulling true force culling off regardless of these defaults.

These options only do anything while Distant Horizons is installed. The quick options screen shows them in its Distant Horizons section in that case. See Distant Horizons Integration.

File: config/flansmodultimate-content-loading.toml

This file controls where the mod looks for content packs and how it prepares generated content assets.

Use forceRegenContentPacksAssetsAndIds = true when you have changed content packs in a way that adds or changes generated assets or IDs. After one successful startup, set it back to false so every launch does not repeat the expensive regeneration.

Example:

contentPacksRelativePath = "flan"
useDefaultCategories = true
forceRegenContentPacksAssetsAndIds = false
contentLoadingThreads = 0

explosionBreakBlocks = false
forceNewExplosionsBreakBlocks = false
flanExplosionsDropBlocks = false

headshotDamageModifier = 3.0

gunRecoilModifier = 0.75

enableDigitalAmmoSystem = true
digitalAmmoDefaultAmount = 100
digitalAmmoMaxAmount = 1000
digitalAmmoSupplyBlocks = [
    "minecraft:barrel"
]
digitalAmmoSupplyAmount = 250

In flansmodultimate-content-loading.properties:

useDefaultCategories=false

This gives you full control over category-based edits, but also removes all built-in category tuning supplied by the mod.

The quick options screen exposes these controls in HUD. All client settings below are in General Settings. Operators can change the server suppression options under Server Settings; the common TOML section is Shootable Settings.

Pack authors can choose FlyBySound (alias missNoise), FlyBySoundRange, Suppression, and SuppressionRange for each ammunition type. An omitted fly-by sound retains the generic sound; an empty value or None silences it. Both ammunition and grenades accept the explosion shake keys; omitted values enable strength 10 within 32 blocks, and an explicit zero disables shake. No bundled definitions are changed by this port. These effects are independent of the source entity: players, NPCs, mounted weapons and ownerless mod projectiles use the same feedback paths.

The server checks the actual travelled segment and sends each round's sound and suppression impulse at most once per player. The shooter, its owner entities, direct-hit players, spectators and players behind intervening solid cover are excluded. Near misses beyond a terminal impact are excluded. Effects are cosmetic: they never change player aim, damage, accuracy, turret orientation or apply potion effects. Suppression darkness respects the hidden-HUD setting; camera effects remain independently configurable.