[Important] --> Always back up your project before updating! <-- [Important]

Before Updating: Move any custom assets outside of the "RealisticCarControllerV4" folder. Delete the entire "RealisticCarControllerV4" folder before importing the updated version.
Editor Scripts: The editor scripts rely on the folder's path, so it’s recommended not to change the directory of the "RealisticCarControllerV4" folder.
Input System: RCC now uses the new Input System. Set "Active Input Handling" to "Input System" or "Both" in your project settings.

[Important] Upgrading from V4.5.0 --> V5.0.0

Delete the old RealisticCarControllerV4 folder from your project. (Custom prefabs, audio clips, and scripts you placed outside that folder are unaffected, keep them where they are.)
Import V5.0.0.
Run Tools → BoneCracker Games → Realistic Car Controller → Welcome Window once, accept any layer / tag prompts.
If you have custom code that subscribes to RCC events, migrate to RCC_Events (see below).
If you converted to URP / HDRP previously, re-run Tools → BoneCracker Games → Realistic Car Controller → Render Pipeline Converter after import.
To enable Photon multiplayer, import Photon PUN 2 (v2.52) and add the RCC_PHOTON scripting define symbol.

[V5.0.0]

Editor Tooling

RCC_Events — centralized static event hub. One class to subscribe to vehicle spawn / destroy / collision, AI spawn / destroy, camera spawn, behavior change, vehicle change, and every input action (engine, gears, lights, indicators, camera, record / replay, slow motion, look back, trailer detach). Full IntelliSense documentation on every event.
Quick Vehicle Setup Wizard — step-by-step editor window that walks beginners through converting a 3D model into a working RCC vehicle: add main controller, validate axis orientation, assign front and rear wheels, create body collider. Replaces the previous wizard's placeholder step with real axis-orientation validation.
Render Pipeline Converter improvements — added an "Import Built-in Shaders" button so projects can roll back from URP / HDRP to Built-in if they converted by mistake. Cleaner multi-step UX, decal material handling, and per-camera URP post-processing setup.
Script Execution Order Manager — automatically applies the correct script execution order on import, so RCC_SceneManager initializes before any vehicle, AI / Recorder inputs land in the same physics frame the controller reads them, and the customizer applies its loadout after the rest of the vehicle is wired up. Travels with the package (Project Settings is not part of .unitypackage exports).

Improvements

Comprehensive XML documentation across every public type, method, parameter, and event — visible in IDE IntelliSense.
[Tooltip] attribute on every serialized field — descriptions show up directly in the Inspector for beginners.
[Range] and [Min] bounds added to numeric serialized fields where the value has a sensible domain.
All runtime Debug.Log calls now guarded with #if UNITY_EDITOR — release builds ship clean.
Domain-Reload-Disabled support — [RuntimeInitializeOnLoadMethod] resets static caches in RCC_Core and RCC_Settings, so projects with Enter Play Mode optimizations enabled no longer carry stale state between runs.
Custom inspectors only repaint when the mouse is over them — noticeably less editor CPU during sessions with several inspectors visible.
Welcome window simplified — removed addon-gated copy paths, fixed text that still referenced V3.
Render pipeline conditional compilation (BCG_URP, BCG_HDRP) audited across all affected files.
BCG Shared Assets package improved.
Documentation rewritten as a 24-chapter HTML guide bundled with the package (Getting Started, Vehicle Setup, Physics, Wheel Colliders, Driving Assists, Damage, Camera, Input, Lights & Effects, AI, Customization, UI, Scripting API, Settings, Editor Tools, Mobile, Render Pipelines, Demo Scenes, Troubleshooting, FAQ, Changelog).

Bug Fixes

Approximately 170 runtime issues addressed across ~80 script files.

Logic bugs

RCC_Settings runtime mutations no longer persist after exiting Play mode. The settings ScriptableObject is cloned when first accessed in Play; SetBehavior, SetMobileController, and other runtime changes no longer dirty the on-disk asset.
RCC_SpeedLimiter cross-vehicle drag interference. Previously, a single shared defaultDrag field meant a second vehicle entering the same limiter inherited the first vehicle's drag on exit. Now keyed per-vehicle in a Dictionary on instance ID.
RCC_Customizer_UpgradeManager incorrect property routing. The Speed property was checking the wrong backing field (handling == null instead of speed == null); BrakeLevel was reading Engine != null instead of Brake != null; HandlingLevel was reading Engine instead of Handling. Wrong components were being auto-created and wrong levels reported to UI.
RCC_Octree neighbor detection and boundary insertion. FindNearestVertex used || where && was required, and vertices that landed exactly on a node boundary previously skipped insertion. Both fixed — deformation accuracy on flat surfaces is now correct.
RCC_Mirror null-camera crash. Missing return after enabled = false plus a missing null guard for CarController caused a NullReferenceException when the Camera component was absent or the vehicle was destroyed mid-frame.
RCC_AICarController list iteration. Reversed-loop RemoveAt calls in CheckTargets and CheckBrakeZones previously skipped the entry immediately after the removed one. Fixed with continue after each removal.
RCC_Exhaust flame null reference. Flame light null check moved before intensity access; additional null guard inside Flame().
RCC_GetBounds crashed on empty renderer arrays or renderers with null meshes. Both now handled gracefully.
RCC_UICanvas_Customizer — decalsButton reference corrected to decalsClass.
RCC.Repair(null) no longer throws.
RCC_CheckUp Rigidbody collection collected the vehicle's own Rigidbody and compared the wrong reference for detachable parts; fixed and cached.
RCC_Installation layer-check used || where && was needed and contained unreachable dead code in CheckLayer.
RCC_Settings.selectedBehaviorType is now bounds-checked against behaviorTypes.Length before indexing, so a misconfigured index can't throw IndexOutOfRangeException.

Null reference protection

Null checks added across components that touch external references (cameras, lights, wheels, transforms, particle systems, detachable parts). RCC.Repair, RCC_Mirror, RCC_Exhaust, RCC_GetBounds, RCC_AICarController, and RCC_Customizer_UpgradeManager all received extra null guards on inputs, transforms, light components, and detachable parts.

General robustness

Division-by-zero guards added where applicable.
Index-out-of-range protections for array and list access.
Race-condition mitigation in singleton initialization.

Compatibility

Unity 2022.3 LTS through Unity 6.x verified.
Built-in, URP, and HDRP render pipelines all supported. Use Tools → BoneCracker Games → Realistic Car Controller → Render Pipeline Converter to switch.
Unity Input System 1.11+ (the only supported input backend).
Photon PUN 2 v2.52 (opt-in via RCC_PHOTON define).
Desktop input, mobile touch UI, and gyroscope steering.
WheelCollider physics — no API changes from V4.5.0.

[Important] Migration

Public static events previously found on RCC_InputManager and RCC_CarControllerV4 have been moved into the new RCC_Events static class. Event behavior is identical — only the host class has changed. Update your subscriptions before upgrading user code.

Before (V4.5.0):

RCC_InputManager.OnStartStopEngine += MyHandler;

RCC_CarControllerV4.OnRCCPlayerSpawned += MyHandler;

After (V5.0.0):

RCC_Events.OnStartStopEngine += MyHandler;

RCC_Events.OnRCCPlayerSpawned += MyHandler;

Full list of relocated events:

Vehicle lifecycle: OnRCCPlayerSpawned, OnRCCPlayerDestroyed, OnRCCPlayerCollision
AI lifecycle: OnRCCAISpawned, OnRCCAIDestroyed
Camera: OnBCGCameraSpawned
Scene state: OnBehaviorChanged, OnVehicleChanged
Input actions: OnStartStopEngine, OnLowBeamHeadlights, OnHighBeamHeadlights, OnChangeCamera, OnIndicatorLeft, OnIndicatorRight, OnIndicatorHazard, OnInteriorlights, OnGearShiftUp, OnGearShiftDown, OnNGear, OnSlowMotion, OnRecord, OnReplay, OnLookBack, OnTrailerDetach

Old release notes

Realistic Car Controller