DayZ Motorbikes (Single-Track Vehicles) & 1.30 Vehicle Refactor

Preflight: rider posture (added 2026-09-28, LFDucati T99; B1 measured on the same day) [EXACT except where marked]. Chosen solely by GetAnimInstance() -> SetVehicleType (exp\scripts\scripts\4_World\Classes\UserActionsComponent\Actions\Interact\ActionGetInTransport.c:104-107) -> fixed state and column in Vehicles.agf (five nodes require literal VehicleType == 10 || VehicleType == 11: :1429, 1474, 1529, 1570, 2806). Neither the model nor the config moves the hands: they are fixed by the handlebar pose clip, and there is no foot IK. GP clip-ons with MOTO1/MOTO2 leave the hands ~40 cm above: custom clips are required. Survivor Animations MOTORCYCLE (16) = car driver body (Offroad Hatchback) with IK hands, 1.29 format graph (crashes 1.30). Corrects references/rider-animation.md:77: 1.29 graphs are TEXT ($AnimGraph 7), not binary. Approach without touching the graph: registered child .asi + SetAnimationInstanceByName, like surrendering (PlayerBase.c:2087-2088, DayZPlayerCfgBase.c:1532-1537): works with the motorbike stopped on dedicated server and local client (measured 2026-09-28, LFDucati B1, LL-530), and stopped and moving with custom clips (LFRider on the H2R, same day, LL-533..535): a DayZATool (ANIMSET5) clip put the stopped rider within 0.4 mm of its FK in those runs (later first-person probe runs saw the stopped head move by several cm between runs and looks: dayz-test-ingame references/session-findings.md, "H2R import (2026-10)"); steering clips are distributed across ±45° of REAL wheel angle on all motorbikes (Vehicles.agf:50, :1466), not at the limit of each one; transitions are exported as full whole-body posture (as additive differences they collapse the skeleton). With observers and in edge cases, untested. Common mod and toolchain: LFRider (not published). Recipe, pitfalls, and the pose in four pieces: references/rider-animation.md §Per-bike pose. Detail: LFDucati research notes (not published).

DayZ 1.30 Experimental (build 1.30.164014) introduces full native engine support for single-track vehicles via the engine simulation type simulation = "motorbike" (exp\bin\bin\config.cpp:1059, in-game bin\config.cpp). At the class architecture level, class Motorbike: Transport is a direct sibling of Car and Boat in native C++ (exp\scripts\scripts\3_Game\Vehicles\Motorbike.c:30, in-game scripts\3_Game\Vehicles\Motorbike.c), not a child of Car. In the game script layer, MotorbikeScript inherits directly from Motorbike (exp\scripts\scripts\4_World\Entities\Vehicles\MotorbikeScript.c:53, in-game scripts\4_World\Entities\Vehicles\MotorbikeScript.c), NOT from CarScript.

Three-Layer Inheritance Hierarchy

1. Engine Config Layer (bin\config.cpp): Transport -> Motorbike (exp\bin\bin\config.cpp:1054-1059, with simulation = "motorbike").
2. 3_Game Script Layer (scripts\3_Game\Vehicles\):
   • TransportType -> MotorbikeType (exp\scripts\scripts\3_Game\Vehicles\Motorbike.c:16-18).
   • TransportOwnerState -> MotorbikeOwnerState (Motorbike.c:20-23).
   • TransportMove -> MotorbikeMove (Motorbike.c:25-27).
   • Transport -> Motorbike (Motorbike.c:30-370).
3. 4_World Script Layer (scripts\4_World\Entities\Vehicles\):
   • MotorbikeOwnerState -> MotorbikeScriptOwnerState (exp\scripts\scripts\4_World\Entities\Vehicles\MotorbikeScript.c:23-25).
   • MotorbikeMove -> MotorbikeScriptMove (MotorbikeScript.c:27-29).
   • Motorbike -> MotorbikeScript (MotorbikeScript.c:53-1765).
   • MotorbikeScript -> Motorbike_01_ColorBase (exp\scripts\scripts\4_World\Entities\Vehicles\InheritedMotorbikes\Motorbike_01.c:1-166).
   • MotorbikeScript -> Motorbike_02_ColorBase (exp\scripts\scripts\4_World\Entities\Vehicles\InheritedMotorbikes\Motorbike_02.c:1-140).

A motorcycle in DayZ 1.30 has no relationship to the traditional four-wheel subsystem: it completely lacks the Axles hierarchy, does not use doors (IsAreaAtDoorFree always returns true), does not require a radiator or vital coolant circuit (IsVitalRadiator() returns false, MotorbikeScript.c:321-324), and the two vanilla motorbikes dispense with a battery because they override NeedElectricitySourceDevice() to false (Motorbike_01.c:33-36, Motorbike_02.c:34-37); the default in Transport is true (Transport.c:821-824) and MotorbikeScript does not change it. In return, the Enfusion engine simulates a dynamic two-wheel balance model with gyroscopic lean (maxLeanAngle[]), decoupled lever and pedal brakes, kickstand (SetKickstand), fall and destabilization (FallOver), and mandatory driver ejection on tipover (CrewShouldEject).

All technical evidence in this skill comes from code and configuration extraction (source_verified) of Experimental 1.30.164014. No dynamic behavior is declared runtime tested (runtime_verified).

Family Selector

Architecture recommendation: for a new motorbike, inherit in Enforce Script directly from MotorbikeScript and copy the structure of Motorbike_01_ColorBase in your config.cpp (see references/config-contract.md). Do not attempt to inherit from CarScript or adapt 4-wheel Axles blocks: simulation = "motorbike" does not use them (invariant 1; exact failure mode is not measured [UNVERIFIED]). If inheriting directly from MotorbikeScript, override NeedElectricitySourceDevice(): without override it returns true and the motorbike would require a battery (Transport.c:821-824).

Day-0 critical path for a new motorbike

Ordered checklist of minimum mandatory deliverables to have an operational motorbike:

1. [EXACT] CfgPatches and CfgVehicles declaration: declare the addon with mandatory dependency on "DZ_Vehicles_Singletrack" (exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:22-31, in-game DZ\vehicles\singletrack\config.cpp). Inherit from MotorbikeScript with simulation = "motorbike".

   class CfgPatches { class MiMoto { units[] = {}; requiredAddons[] = {"DZ_Data", "DZ_Vehicles_Singletrack"}; }; };

2. [EXACT] class Crew block: define class Driver and class CoDriver: Driver pointing to actionSel = "seat_driver", proxyPos = "crewDriver", getInPos = "pos_driver", getInDir = "pos_driver_dir", and both with isDriver = 1; (config.cpp:67-85).
3. [EXACT] class SimulationModule block: declare class Wheels with class Front and class Rear (without Axles), class Brakes with Front (input = 1) and Rear (input = 0), and lean curves in class Steering (config.cpp:228-343).
4. [EXACT] Animation sources (AnimationSources): declare shock absorbers damper_1, damper_2 and wheel state AnimHitWheel_1, AnimHitWheel_2 (config.cpp:112-148, 344-364). If it has a flip-up seat, add SeatDriver.
5. [EXACT] Damage system (DamageSystem): define GlobalHealth (1000 HP) and the zones from Motorbike_01: Chassis, Fender (transfer target for Front), Engine (inventorySlots[] = {"SparkPlug"}), Front, Reflector_1_1, Back, and FuelTank, plus GUIInventoryAttachmentsProps (config.cpp:365-515). A glass slot that should hide at 0.0, as in Reflector_1_1, is a config shape the Pack has not seen work in game: see dayz-vehicles references/vehicle-config-and-modelcfg.md, end of §6b (SP-483).
6. [EXACT] Wheels and Proxies: define classes derived from MotorbikeWheel for front and rear wheels with their _Ruined versions in CfgVehicles (config.cpp:155-214), and proxies in CfgNonAIVehicles (config.cpp:1061-1083):

   class MiMoto_Wheel_1: MotorbikeWheel { scope = 2; radius = 0.29; width = 0.06; tyreLateralFriction = 3.0; };

7. [EXACT] High-speed anti-snag geometry: define speedGeomActivation = 0.29; and speedGeoms[] = {"geotohide"}; (config.cpp:226-227).
8. [EXACT] 4_World Script Class: create class derived from MotorbikeScript (exp\scripts\scripts\4_World\Entities\Vehicles\InheritedMotorbikes\Motorbike_01.c:1-166). Configure in constructor impact damages (m_VehicleContactDamageCoef, m_CrewContactDamageCoef), engine and horn SoundSets, and register lights in m_LightsComponent:

   m_VehicleContactDamageCoef = 0.03;
   m_CrewContactDamageCoef = 0.018;

9. [EXACT] Mandatory script overrides: implement GetAnimInstance() returning VehicleAnimInstances.MOTO1 (10) or MOTO2 (11), HasDirectionalInOutAction() (true), GetSeatAnimationTypeDirectional(), GetTransportCameraDistance(), GetTransportCameraOffset(), and NeedElectricitySourceDevice() (false on magneto/kickstart bikes).
10. [DESIGN] Geometry and P3D model: ensure bone "drivewheel" on the front fork, light memory points (light_1_1, light_1_2_reverse), smoke (ptcExhaust_start/end, ptcEnginePos), fuel cap (refill), and damage selections (dmgZone_*). Details in references/forward-contract.md.
11. [EXACT] Sounds: reference engine, exhaust, shock absorber, and horn SoundSets defined in exp\sounds_hpp\DZ\sounds\hpp\config.cpp (motorbike SoundSets :98179-98909, SoundShaders :59253-59918):

    m_EngineStartOK = "Motorbike_01_engine_start_SoundSet";
    m_HornComponent.RegisterSound(VehicleHornMode.SHORT, "Motorbike_01_Horn_Short_SoundSet");

12. [DESIGN] Economy and Spawn: register in types.xml and cfgspawnabletypes.xml with spark plug (SparkPlug) and wheels installed.
13. [EXACT] Decide rider posture BEFORE modeling (added 2026-09-19, LFDucati): no runtime hand adjustment exists. Each vanilla motorbike has its own column in the animation set ("Jawa_05", "Jawa_Bitrak": exp\anims_workspaces\DZ\anims\workspaces\player\player_main\player_main.ast:1114-1121) with its own clip set (26 and 27 distinct .anm clips; e.g. Vehicle.Jawa_05.DriverSteeringMain → …/Jawa_05/p_motorbike_01_driver_steering_pose.anm, player_main.asi:5131; Vehicle.Jawa_Bitrak.DriverSteeringMain → …/Jawa_Bitrak/p_motorbike_02_driver_steering_pose.anm, player_main.asi:5179), and hand IK takes its targets LHandIKTarget/RHandIKTarget from those clips (AnimNodeIK2Target0 with child SteeringBlend, Vehicles.agf:17-46), not from the motorbike P3D. There are no Arma-style config keys (driverLeftHandAnimName: 0 occurrences in vehicles_singletrack, vehicles_wheeled, and bin config.cpp). Consequence: either you fit the handlebar/footpegs/seat of YOUR model to the contact points of MOTO1 or MOTO2 (measure them in-game on the vanilla bike before touching ergonomics), or you add a column with custom clips, which means modifying player_main (the single-animation-mod wall, see references/rider-animation.md §5). (corrected 2026-09-28) There is a third way without touching player_main: a child .asi with custom clips only on your bike class (preflight above; tested in-game stationary and moving on the H2R). A handlebar of a different width does NOT fix itself.

The ten invariants that break a motorbike

Each rule must be strictly followed to prevent critical failures in the entity:

1. Flat Wheels in config, NEVER Axles block

• Symptom [UNVERIFIED, expected and not measured in-game]: simulation initialization failure when spawning the entity; exact failure mode (RPT error, inert entity, or process crash) has not been measured.
• Cause: The simulation = "motorbike" engine reads directly class Wheels { class Front; class Rear; } (exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:88-106). The class Axles hierarchy belongs exclusively to simulation = "car" / "carx".
• Citation: exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:88-106, 305-342.
• Remedy: Remove any Axles block from SimulationModule. Declare Front and Rear directly inside Wheels: Wheels:

  class Wheels: Wheels
  {
      class Front: Front { inventorySlot = "MiMoto_Wheel_1"; animDamper = "damperfront"; };
      class Rear: Rear   { inventorySlot = "MiMoto_Wheel_2"; animDamper = "damperback"; };
  };

2. Brakes Front input=1 / Rear input=0

• Symptom: The front brake lever does not respond, or the rear pedal blocks the front wheel unexpectedly.
• Cause: On motorbikes, the front brake is bound to the handbrake channel (input = 1) and the rear to the regular pedal brake (input = 0). The API documents it: SetBrake is the rear brake and SetHandbrake is the front brake (exp\scripts\scripts\3_Game\Vehicles\Motorbike.c:129-139).
• Citation: exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:257, 266.
• Remedy: In SimulationModule -> Brakes, define class Front { input = 1; ... }; and class Rear { input = 0; ... };:

  class Brakes
  {
      class Front { input = 1; pressureBySpeed[] = {0,0.85,10,0.7,40,0.6,60,0.5,80,0.5}; };
      class Rear  { input = 0; pressureBySpeed[] = {0,0.95,10,0.1,20,0.1,40,0.1,50,0.1}; };
  };

  The rear pressure drops from 0.95 at standstill to 0.1 from point 10 on the curve (config.cpp:267); whether this serves to prevent rear axle skids is an interpretation [UNVERIFIED].

3. "drivewheel" bone in P3D for headlight

• Symptom: The headlight light cone remains pointed rigidly forward along the chassis and does not rotate when turning the handlebars.
• Cause: MotorbikeScript.c:1107-1109 looks up the "drivewheel" bone in a hardcoded manner via GetBoneIndex("drivewheel") to align the light cone with the front fork.
• Citation: exp\scripts\scripts\4_World\Entities\Vehicles\MotorbikeScript.c:1107-1109.
• Remedy: Name the front fork and handlebar selection "drivewheel" in the P3D geometry and in skeletonBones[] of your model.cfg:

  int driveWheelIndex = GetBoneIndex("drivewheel");
  m_LightsComponent.AttachLightOnObject("Front", GetMemoryPointPos(m_HeadLightPoint), vector.Zero, VehicleLightMode.SEGREGATED, driveWheelIndex);

4. SeatDriver and CanGetIn entry condition

• Symptom: The player receives no prompt to get on the bike (CanGetIn() returns false).
• Cause: If inheriting from Motorbike_01_ColorBase, the script requires GetAnimationPhase("SeatDriver") == 0.0 (Motorbike_01.c:97). If your model lacks the "SeatDriver" animation, the condition permanently fails.
• Citation: exp\scripts\scripts\4_World\Entities\Vehicles\InheritedMotorbikes\Motorbike_01.c:92-98.
• Remedy: For motorbikes without a flip-up seat, inherit directly from MotorbikeScript or override CanGetIn() without evaluating "SeatDriver". If keeping the seat, declare SeatDriver in AnimationSources with initial phase 0.0:

  class AnimationSources: AnimationSources
  {
      class SeatDriver { source = "user"; initPhase = 0.0; animPeriod = 1.0; };
  };

5. Contact damage coefficients and instant death

• Symptom: The rider dies instantly upon grazing a minor obstacle at low speed.
• Cause: Each contact produces two quantities on the server (CheckContactCache, MotorbikeScript.c:1252-1357, called inside if (g_Game.IsServer()) at :743-758): vehicle damage dmg = |impulso × m_VehicleContactDamageCoef| (:1263) and the crew damage base crewDmgBase = |impulso / masa × 500 × m_CrewContactDamageCoef| (:1264, calculates as if the motorbike weighed 500 kg). Threshold tiers are decided with dmg; only the last damages the crew, and there death depends on crewDmgBase (DamageCrew, :1360-1412).
• Citation: exp\scripts\scripts\4_World\Entities\Vehicles\MotorbikeScript.c:1263-1264, 1301-1350, 1369-1383 and exp\scripts\scripts\3_Game\constants.c:898-901.
• Tiers according to vehicle dmg (constants.c:898-901):
  • dmg < 10 (MOTORBIKES_CONTACT_DMG_MIN): ignored (:1301-1302).
  • 10 ≤ dmg < 25 (MOTORBIKES_CONTACT_DMG_THRESHOLD_SMALL): damage to zone without transfer (NO_TRANSFER) and light crash sound (:1310-1320).
  • 25 ≤ dmg < 40 (MOTORBIKES_CONTACT_DMG_THRESHOLD_MID): FallOver() and light sound; crew takes no damage (:1321-1331).
  • dmg ≥ 40: DamageCrew(crewDmgBase), FallOver() and heavy sound (:1332-1344).
  • From dmg ≥ 10, ProcessDirectDamage applies dmg to the impacted zone (:1350).
• Inside DamageCrew: if crewDmgBase > 80 (MOTORBIKES_CONTACT_DMG_KILLCREW, strictly greater) it executes crew.SetHealth(0.0) (:1369, 1383); otherwise, it subtracts shock from 50 to 150 and health from 2 to 100, interpolated between 25 and 80 (:1387-1409).
• Remedy: m_VehicleContactDamageCoef decides when the motorbike falls (dmg ≥ 25) and when the crew is damaged (dmg ≥ 40); m_CrewContactDamageCoef decides if that damage kills (crewDmgBase > 80). Vanilla values: 0.03 / 0.018 (Motorbike_01.c:5-6) and 0.035 / 0.012 (Motorbike_02.c:5-6).

6. Lean angles (maxLeanAngle) and tipover (tipoverAngle)

• Symptom [UNVERIFIED, expected and not measured in-game]: the motorbike falls over on its own when accelerating or stays vertical without leaning in turns.
• Cause: Steering declares lean curves and threshold tipoverAngle = 50.0; both are consumed by native simulation (simulation = "motorbike"), not script, so their exact effect above the threshold cannot be verified in text [UNVERIFIED].
• Citation: exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:231-243.
• Remedy: Copy the validated table from Motorbike_01:

  class Steering
  {
      tipoverAngle = 50.0;
      maxLeanAngle[] = {1,0,5,8,15,10,30,17,40,22,80,30};
      maxSteeringAngle[] = {1,40,5,40,15,20,30,5,40,3,80,1};
      directControl[] = {0.0,1.0,5.0,1.0,30.0,0.6,60.0,0.2,80.0,0.0};
  };

7. Kickstand (Kickstand) in lifecycle

• Symptom [UNVERIFIED, expected and not measured in-game]: the motorbike collapses sideways upon spawning on the ground.
• Cause: the vanilla constructor deploys the kickstand using native method SetKickstand(1); what native physics specifically does with that value is an assumption (see digest A, SUPOSICIONES 2) [UNVERIFIED].
• Citation: exp\scripts\scripts\4_World\Entities\Vehicles\MotorbikeScript.c:141.
• Remedy: Ensure the constructor maintains SetKickstand(1);. No retail script retracts the kickstand: the only SetKickstand(0.0) is in OnInput within #ifdef DIAG_DEVELOPER and only runs with debug mode active (MotorbikeScript.c:841-843, 915). If it retracts while riding, native simulation does it [UNVERIFIED].

8. Hidden geometry at speed (speedGeomActivation / speedGeoms)

• Symptom: The motorbike collides with invisible terrain micro-bumps or is flung into the air at high speed.
• Cause: The support stand geometry collides with ground unevenness if not disabled when moving at high speed. In Motorbike_01 it activates at 0.29 and in Motorbike_02 at 0.27.
• Citation: exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:226-227, 729-730.
• Remedy: Define in config speedGeomActivation = 0.29; and speedGeoms[] = {"geotohide"};, isolating kickstand geometry into the "geotohide" component of LOD Geometry.

9. Mandatory modular components (Lights, Horn, VFX)

• Symptom [UNVERIFIED, expected and not measured in-game]: failure when accessing an uninstantiated component in the lighting code path, or horn without sound and without noise for infected.
• Cause: In DayZ 1.30, lights no longer reside in m_Headlight nor the horn in m_CarHornState; they operate in independent components.
• Citation: exp\scripts\scripts\4_World\Entities\Vehicles\MotorbikeScript.c:113, 127, 139.
• Remedy: Instantiate VehicleLightsComponent, VehicleHornComponent, and VehicleVFXComponent in the constructor, registering their corresponding profiles and SoundSets:

  m_LightsComponent = VehicleLightsComponent(this);
  m_HornComponent = VehicleHornComponent(this);
  InitializeParticles(); // Instancia m_VFXComponent

• [EXACT] Vehicle lights are toggled with UAToggleVehicleLights via ToggleVehicleLightsActionInput (exp\scripts\scripts\4_World\Classes\UserActionsComponent\ActionInput.c:849-855); ActionSwitchLights.GetInputType() returns that class (ActionSwitchLights.c:16-19). UAToggleHeadlight is the headtorch (ToggleLightsActionInput, ActionInput.c:776-782). Both names exist in exp\bin\bin\constants.xml:90-91. Detail: references/actions-hud-lights-sounds.md §5.

10. Blowtorch-exclusive repair actions in build 1.30.164014

• Symptom: The player receives no action to repair engine or chassis when aiming with a wrench or epoxy putty.
• Cause: In this Experimental build, motorbike repair actions are assigned only to the blowtorch (Blowtorch.c). Additionally, ActionRepairMotorbikeEngine was not registered in ActionConstructor.c.
• Citation: exp\scripts\scripts\4_World\Entities\ItemBase\Blowtorch.c:109, 111, 113 (the only motorbike repair AddAction in all of scripts) and exp\scripts\scripts\4_World\Classes\UserActionsComponent\ActionConstructor.c:252-260 (registration of motorbike actions, without ActionRepairMotorbikeEngine).
• Remedy: If your mod requires repairing with traditional hand tools, you must bind actions to items via modded class and insert them into ActionConstructor:

  modded class ActionConstructor
  {
      override void RegisterActions(TTypenameArray actions)
      {
          super.RegisterActions(actions);
          actions.Insert(ActionRepairMotorbikeEngine);
      }
  }

Measured lessons from LFDucati (1.30.164014, September 2026)

Measured in-game with a 157 kg Desmosedici GP16 inherited from Motorbike_02_ColorBase (DayZDiag, dedicated server and client). Each rule cites its lesson from the vault (AI/20_Knowledge/lessons-learned.md), which stores the narrative and numbers.

1. Overall first gear must be short. [EXACT] With the automatic clutch, first × driveRatio between 20 and 26 starts (Motorbike_02: 25.7; LFDucati settled on 20); 6.77, that of a real MotoGP, does not move the bike: 0.05-0.1 km/h wide open and rpm stuck at two values. Decide it with a session A/B using the vanilla drivetrain as control, and measure the ratio applied by the engine (rpm·π/30 ÷ ω of the drive wheel) to confirm config loaded. On 1.30 motorbikes w0 is the front: distinguish wheels by rolling radius (ω·r = v), not by WheelGetPositionLS (LL-506).
2. Suspension is sized to the load of each wheel. [INFERRED] The model fitting measurements is F = k (u + travelMaxDown), with the wheel hanging from the modeled axle and u linear in the damper phase (phase 0 = -travelMaxDown, phase 1 = +travelMaxUp). [EXACT] With it, in the variant resting solely on the springs the sum of forces / g yielded 157.1 kg for a 157.0 kg bike; in the product red variant the springs only carried 132.7 kg and the rest rested on the Engine box against the ground. For it to rest on the axle, travelMaxDown = F / k on each wheel (or increase k and scale damping with √(k·m)). A motorbike inheriting suspension from a lighter one inherits its sag; if the sum does not match the mass, look for what else is resting on the ground (LL-512).
3. No Geometry box can touch the ground at full suspension compression. [EXACT] Each hit is a contact: damage deciding the tier is Math.AbsInt(data[0].m_Impulse * m_VehicleContactDamageCoef) (MotorbikeScript.c:1263) and, from 25 upwards, the branches call FallOver() (:1310-1342), throwing the rider off (invariant 5). Gate before testing: lowest point of each component, minus remaining compression from rest, ≥ 5 mm; and m_VehicleContactDamageCoef scaled by mass (× m_vanilla / m_propia) so the same hit counts equally (LL-507).
   • (LL-507 details) [EXACT] If a ..._damper_land box is lowered to seat the physical wheel, shrink it keeping the SAME centre - the physical wheel does not move; and log contacts server-side (Transport.OnContact: zone, point, impulse change) before tuning coefficients. (Measured in game, DayZ 1.30.164014 Exp.)
4. The rider proxy only positions and yaws around the vertical. [EXACT] The engine applies the crew proxy frame but keeps the player vertical: a proxy tilted 20 degrees forward resulted in yaw of about 17 degrees and zero lean; a rolled proxy produced a player standing 30 cm off the bike. Crouching or leaning the rider requires animation (preflight above and references/rider-animation.md) (LL-511, LL-509).
5. A hidden selection only changes material if model.cfg lists it in sections[]. [EXACT] Config alone is not enough and the failure is silent: check it in the ODOL (sectional selection), not in config. Lights render by index in hiddenSelections: headlight 0, brake 1, tail light 2, and dashboard 3 (MotorbikeScript.c:114-122), and Motorbike_02 moves brake to 2 of the tail light (Motorbike_02.c:20-21); in a custom model those positions might fall onto livery sections (LL-508).

How to verify

1. Offline linter before opening the game: Run the offline validator on your addon directory: python <KNOWLEDGE_PACK>/tools/dayz-script-validator/scripts/script_validator.py <addon_root>
   • Check errors and warnings keys at the root of output JSON.
   • Return code is 0 (PASS), 1 (FAIL), or 2 (WARN).
   • Always gate by len(errors) == 0; a clean tree with minor warnings returns 2 and is valid.
   • Check that no broken references exist in Enforce .c, layouts, config.cpp, or .rvmat.
   • Use delta comparison against the unchanged base tree to isolate errors introduced by your mod.
2. In-game verification ladder (via DayZ-MCP or local Diag server):
   • Step 1 (Spawn): Spawn the bike using the world_spawn tool on a local server run with -filePatching. Confirm it stays upright on the kickstand without endless oscillations or sinking into the ground.
   • Step 2 (Render): Check that wheels show their correct proxies, rvmat materials respond, and there are no grey panels or invisible meshes due to incorrect selection names.
   • Step 3 (Get-In): Trigger vehicle_get_in_client approaching from the left flank and then from the right; verify that ActionGetInTransport activates directional animations GetIn_L and GetIn_R.
   • Step 4 (Starting and Driving): Trigger ActionStartEngineMotorbike or the engine_set tool. Listen for kickstart lever sound, verify front headlight rotates together with handlebars (drivewheel), and check that the 3rd person camera follows steering with spring damping.
   • Step 5 (Driving Telemetry): Monitor RPM, speed, and gear via vehicle_telemetry or telemetry_read to verify SimulationModule response.
   • Step 6 (Fall and Recovery): Cause a side collision or sharp turn to induce a forced tipover. Check that the player is ejected to the ground (CrewShouldEject) and that ActionPickUpMotorbike allows picking it up via action_use.

   Measured correction (2026-09-19, LFDucati; citations re-read in DayZ_MCP_dev on that date): this ladder CANNOT be run today with DayZ-MCP on Experimental 1.30. (a) The approved launcher only starts Stable: the executable is hardcoded in tools\native-launchers\dayz-test-v1\worker-runtime.json (all 10 projects point to ...\common\DayZ\DayZDiag_x64.exe) and the daemon only accepts <DAYZ_GAME_PATH>\DayZDiag_x64.exe, a global setting (tools\dayz_mcp\daemon.py:552-557, process_lifecycle.py:1782-1793). (b) The @DayZ_MCP addon is unaware of Motorbike (0 occurrences in addon\): control and telemetry cast to CarScript (addon\scripts\5_Mission\MCPClientBridge.c:1191, 2812-2826), so engine_set, vehicle_control, and the engine portion of vehicle_telemetry do not see a motorbike, which in 1.30 inherits from Transport and not from CarScript. (c) There is no verb to read player bones (rider pose). Approach used while 1.30 is Experimental: custom diagnostic addon with scenario in a modded MissionServer behind a command line parameter, LFD_… output in script_*.log, two .bat files pointing to DayZ Exp\DayZDiag_x64.exe launched via cmd /c start and a Python driver awaiting log markers (kit: LFDucati probe kit, not published). Seating the player from the server produces crew without HumanCommandVehicle on client (skill dayz-test-ingame §SP-295): serves to measure pose on server, not to validate actions or HUD.

3. What to look for in the RPT file (server-profiles/ or client-profiles/) [UNVERIFIED: message texts are illustrative, not measured; search by symbol]:
   • Cannot load surface info or Undefined sound shader: missing SoundSets or particles in CfgSurfaces.
   • AnimationSource ... not found: missing source registration in config AnimationSources.
   • Bone 'drivewheel' not found: missing bone in front fork of P3D model.
   • Spawn failure with uninitialized simulation: check if an Axles block was configured instead of Wheels (exact failure mode not measured).

Status of this build (WIP Experimental 1.30.164014)

Work-in-progress aspects detected in Bohemia code that could change before Stable:

1. Provisional unconsciousness ejection: In exp\scripts\scripts\4_World\Entities\DayZPlayerImplement.c:2452-2458, motorbike tipover triggers eModifiers.MDF_UNCONSCIOUSNESS because the native ragdoll command was not finished in time. Bohemia is expected to replace this with a dedicated ragdoll command.
2. Orphaned engine repair action: ActionRepairMotorbikeEngine.c exists on disk, but is not inserted into ActionConstructor.c:252-260 nor bound to hand tools. Only ActionRepairMotorbikeEngineWithBlowtorch operates via blowtorch.
3. Undefined rvmat material properties: MotorbikeScript.c:114-122 registers selections whose material is read with ConfigGetString (VehicleLightsComponent.c:77) from properties such as frontReflectorMatOn, which vehicles_singletrack\config.cpp does not declare (cars do, e.g. vehicles_wheeled\DZ\vehicles\wheeled\config.cpp:895).
4. Displaced audio definitions: exp\sounds_vehicles\DZ\sounds\vehicles\config.cpp contains only CfgPatches. All motorbike SoundSets reside in exp\sounds_hpp\DZ\sounds\hpp\config.cpp:98179-98909, and their SoundShaders in :59253-59918.
5. Alignment with 1.29 community guides: Many vehicle modding guides assumed methods such as CreateFrontLight, CarPartsHealthCheck, or variables such as data[0].impulse. In 1.30 these signatures have been completely replaced or encapsulated (see references/vehicle-1.30-refactor.md).
6. Vehicle lights input vs headtorch: ActionSwitchLights binds UAToggleVehicleLights, not UAToggleHeadlight. An inputs.xml declaring only UAToggleHeadlight will not switch off the headlight. See references/actions-hud-lights-sounds.md §5.

Cite-then-verify

Every technical claim in this skill includes the source file path and exact line range relative to extraction root <extract-root>/1.30.164014/.

• If you need to verify a citation, open the corresponding file at that exact line and check the symbol.
• Last full audit: 2026-09-19. All file:line citations, [EXACT] blocks (byte-for-byte identical), and references/sources.md counts were verified against the extraction; displaced citations and claims regarding contact damage, kickstand (DIAG only), default battery, Jawa_05 clips, and sound ranges were corrected. Previous copies: *.bak-20260919-pre-audit. Still unverified: anything depending on native simulation (curve units, effect of tipoverAngle).
• When Bohemia publishes a new Experimental build or Stable version of DayZ 1.30, DO NOT overwrite the current extraction directory. Extract the new version into a sibling directory identified by its build number (for example <extract-root>/1.30.XXXXXX/), run a textual diff against 1.30.164014, and update shifted line numbers.

References Index

• references/config-contract.md: Open to copy literal [EXACT] config.cpp blocks (Crew, SimulationModule, DamageSystem, Wheels, AnimationSources, speedGeoms) and view the complete motorbike parameter table.
• references/script-api.md: Open to view proto native signatures from Motorbike.c, stability callbacks, MotorbikeScript lifecycle, and differences from CarScript.
• references/actions-hud-lights-sounds.md: Open to implement or fix kickstart actions, ground pickup, MotorBikeHud instrumentation, light/horn components, and exact sounds_hpp SoundSets. Includes §5: UAToggleVehicleLights vs UAToggleHeadlight.
• references/rider-animation.md: Open when configuring rider poses, handlebar IK, Vehicles.agf graph nodes (MotorBikeSTM), directional animations, or 3rd person camera.
• references/vehicle-1.30-refactor.md: Open when migrating a car mod from 1.29 to 1.30; contains deprecated method list, component migration, and 1.29 guide myth table.
• references/forward-contract.md: Open for the full production checklist before packaging a new motorbike and to know what to measure on the P3D model.
• references/sources.md: Open to audit extracted sources, verify total line count of each cited file, and understand audio PBO layout.
• references/vanilla-p3d-anatomy.md (added 2026-09-19): Open for the REAL P3D/model.cfg anatomy of Motorbike_01 and Motorbike_02 read from ODOL v56 binaries — mass and center of mass, LODs with resolution and faces, skeleton with parents, all 44/60 animations with their source, angles and axes, LOD Memory points with coordinates, proxies, selections, and named properties. It is the parity benchmark for a new motorbike. parsed state: read its header before citing any number.

WHAT THIS SKILL COULD NOT VERIFY

1. Binary 3D models (.p3d): Exact face selections, memory points not cited in script, and collision LODs of motorbike_01.p3d and motorbike_02.p3d cannot be inspected in text; they must be measured with dayz-p3d-audit or P3D analysis tools.
   • (added 2026-09-19, LFDucati) 1.30 P3Ds are ODOL v56 (1.29 = v54) and the external ODOL->MLOD converter only reads v54: today they CANNOT be measured without patching the reader; see the §Preflight of that skill (an unpublished reader patch is in progress). Verified via binary search in Motorbike_01.p3d: drivewheel, damper_1, damperfront, kickstand, geotohide, pos_driver, light_1_1, refill, and 49 proxy: names exist.
   • (added 2026-09-19; corrected 2026-09-19) Corrected errata: the Motorbike_02 column in table §6 of references/config-contract.md (lines 512-535) had incorrect values (tipover, steering/lean tables, torque curve, idle, redline, ratios); it now matches exp\vehicles_singletrack\DZ\vehicles\singletrack\config.cpp:736-738, 786, 791, 794, 806. Motorbike_01 values were correct, but there were shifted line citations in both columns (Steering, torque, ratios, caster, and scripts), also corrected. Previous copy: references/config-contract.md.bak-20260919.
2. Vanilla motorbike model.cfg file: Not included in plain text inside extracted Bohemia PBOs. Bone names are only known when explicitly referenced in script ("drivewheel").
3. Internal C++ physics calculations: The gyroscopic solver, internal stability algorithm, and Enfusion dynamic balance calculation reside compiled in DayZDiag_x64.exe and are not accessible via Enforce Script.
4. In-game tuning of tyre lateral friction: Wheel friction tables (tyreLateralFriction, tyreLongitudinalFriction) are verified in config, but grip feel on wet curves or gravel requires dynamic in-game testing.

FIN-SKILL-DRAFT