Vehicle Setup

Table of Contents

This guide walks you through setting up a vehicle with Realistic Car Controller Pro (RCCP). Whether you prefer a guided wizard or hands-on manual setup, this page covers both approaches in detail.

Overview

There are two ways to set up a vehicle in RCCP:

Opening the Setup Wizard

You can open the wizard from two menu paths:

The wizard window appears with a progress bar at the top and Back/Next buttons at the bottom. You can move freely between steps before clicking Finish.

Preparing Your 3D Model

Before running the wizard (or setting up manually), your vehicle model needs to meet a few requirements. Getting these right saves a lot of troubleshooting later.

Model Requirements

Requirement Why It Matters
Wheel meshes must be separate GameObjects RCCP needs to spin, steer, and suspend each wheel independently. Wheels baked into the body mesh cannot move.
Each wheel should be its own child object (e.g., Wheel_FL, Wheel_FR, Wheel_RL, Wheel_RR) The wizard and auto-detection rely on finding individual wheel objects in the hierarchy.
The vehicle model should face forward along the Z axis Unity's forward direction is +Z. If your model faces a different direction, the vehicle will drive sideways.
Scale should be realistic (a typical car is roughly 4-5 meters long in Unity units) Physics behaves unpredictably with very small or very large objects. One Unity unit equals one meter.
The pivot point of each wheel should be at the center of the wheel WheelColliders are placed at the wheel pivot. If the pivot is offset, the wheel will appear to float or sink.
The body mesh should not include wheel geometry If wheels are part of the body, you will see duplicate wheels (the body's static wheels plus RCCP's moving wheels).

Quick Checklist

Setup Wizard Walkthrough

The wizard has 7 steps (labeled Step 1 through Step 7 in the window). Each step focuses on one aspect of the vehicle.

Step 1: Basic Settings

This is where you select your vehicle and set its core properties.

What to do:

  1. Select your vehicle GameObject in the Hierarchy panel (click on it)
  2. Open the Setup Wizard -- it automatically detects your selection
  3. The wizard cleans up the name (removes common suffixes like "(Prototype)" or "by Author")
  4. Set the following fields:
Field Default Description
Vehicle Name Auto-detected from GameObject name The display name for your vehicle. Also becomes the GameObject name after setup.
Mass (kg) 1350 The total weight of the vehicle. This affects acceleration, braking distance, and suspension behavior.
Handling Type Balanced Controls how assist systems (steering helper, traction helper, angular drag) are configured.

Handling Type presets explained:

Preset Steer Helper Traction Helper Angular Drag Best For
Balanced 0.1 0.125 0.15 Good all-around default
Stable 0.2 0.3 0.3 Casual or mobile players who want easier control
Realistic 0.025 0.05 0.075 Simulation players who want minimal assists

Typical mass values by vehicle type:

Vehicle Type Mass Range (kg)
Small car / hatchback 1000 - 1200
Sedan 1300 - 1500
SUV / crossover 1800 - 2200
Truck / heavy vehicle 3000+

Model Preparation options: If the wizard detects that your model is a prefab, has existing Rigidbodies, or has existing WheelColliders, it shows additional toggles:

Scene readiness: The wizard also checks if your scene has an RCCP Camera and a ground collider. If either is missing, you will see a warning with instructions on how to add them.

Step 2: Wheel Assignment

This step identifies which child objects are your vehicle's wheels and assigns them to front and rear axles.

Auto-detection: When you enter this step, the wizard automatically runs wheel detection. It analyzes the model hierarchy looking for objects with names like "wheel", "tire", "rim", or position patterns like "FL", "FR", "RL", "RR". Detected wheels are highlighted in the Scene view:

What to do:

  1. Check if auto-detection found all 4 wheels correctly
  2. If a wheel is in the wrong slot, use the Swap L/R button to swap left and right
  3. If auto-detection missed a wheel, drag and drop the correct GameObject from the Hierarchy into the field
  4. If auto-detection found nothing, manually assign all four wheels using the object fields
Field Description
Front Left The front-left wheel mesh GameObject
Front Right The front-right wheel mesh GameObject
Rear Left The rear-left wheel mesh GameObject
Rear Right The rear-right wheel mesh GameObject

Wheel Type preset: At the bottom of this step, choose a wheel friction preset:

Preset Description Use Case
Balanced Good all-around grip with moderate slip Default choice for most games
Stable More grip, less slip Easier to control, good for beginners or arcade feel
Realistic Closer to real-world tire behavior with more pronounced slip Simulation-style driving
Slippy Low grip, high sideways slip Drift games or ice/mud surfaces

The wheel type controls the forward and sideways friction curves applied to every WheelCollider on the vehicle. You can fine-tune these curves later in Settings.

Note: You must assign at least 2 front wheels and 2 rear wheels before the Next button becomes available. For vehicles with more than 4 wheels (6-wheelers, 8-wheelers), you can add extra axles manually after the wizard finishes.

Step 3: Suspension Settings

This step configures how the wheels connect to the vehicle body -- how they bounce, compress, and absorb impacts.

Auto-calculation: Suspension values are automatically computed from the vehicle mass you entered in Step 1: - Spring Force = Mass x 30 - Damper Force = Spring Force x 0.1

For a 1350 kg vehicle, that gives Spring = 40,500 N and Damper = 4,050 N.

Field Default Range Description
Suspension Distance (m) 0.2 0.05 - 0.5 How far the wheel can travel up and down from its rest position. Increase for off-road vehicles (0.3 - 0.5), decrease for low sports cars (0.1 - 0.15).
Spring Force (N) Auto from mass 1000+ How stiff the suspension is. Higher values make the ride stiffer and reduce body roll. Too low and the vehicle bottoms out.
Damper Force (N s/m) Auto from mass 100+ How quickly the spring stops bouncing. Higher values reduce oscillation. Too high and the suspension feels rigid.

Recalculate from Mass button: If you changed the mass in Step 1 and want to recalculate spring and damper values, click this button.

Tips: - For sports cars: lower suspension distance (0.1 - 0.15), higher spring force - For SUVs and off-road: higher suspension distance (0.25 - 0.4), moderate spring force - For trucks: higher spring force to support the weight, moderate suspension distance - These values apply to all wheels initially. After setup, you can fine-tune each axle independently on its RCCP_Axle component.

Step 4: Engine and Drivetrain

This step configures the engine power and how it reaches the wheels.

Auto-calculation: Max Engine Torque is automatically computed as Mass x 0.2. For a 1350 kg vehicle, that gives 270 Nm.

Field Default Description
Drive Type RWD Which wheels receive engine power (see table below)
Max Engine Torque (Nm) Auto from mass Peak torque the engine produces. Higher = faster acceleration.
Min Engine RPM 800 Idle RPM. The engine stays at or above this speed.
Max Engine RPM 7000 Redline RPM. The engine cannot exceed this speed.
Max Speed (km/h) 240 Top speed limiter. The gearbox ratios are adjusted to match.

Drive Type options:

Type Full Name Power Goes To Best For
FWD Front Wheel Drive Front wheels only Everyday cars, less oversteer, good traction in rain
RWD Rear Wheel Drive Rear wheels only Sports cars, drifting, most common for fun driving games
AWD All Wheel Drive All wheels Off-road, rally, SUVs, best traction on all surfaces

When you select AWD, the wizard creates two Differential components -- one for the front axle and one for the rear axle. FWD and RWD use a single Differential.

Recalculate Torque from Mass button: Recomputes the recommended torque if you changed the mass.

Validation: The wizard warns you if: - Max Torque is below 100 Nm (too low for most vehicles) - Min RPM is below 600 (engine would stall unrealistically) - Max RPM is above 10,000 (unusually high for most engines)

Step 5: Addon Components

This step lets you choose which optional vehicle systems to include. All addons are enabled by default -- you deselect any you do not need.

Component What It Does
Inputs Keyboard, gamepad, and mobile touch controls. You almost always want this unless you are building AI-only vehicles.
Dynamics Aerodynamic drag, downforce, engine inertia, and weight transfer simulation. Adds realism at higher speeds.
Stability Electronic driving aids: ABS (anti-lock brakes), ESP (electronic stability), TCS (traction control), and steering helpers.
Customizer Runtime paint changes, wheel swaps, and performance upgrades. Useful for garage/customization menus.
Lights Headlights, brake lights, reverse lights, and turn indicators.
Damage Mesh deformation on impact and detachable parts (bumpers, doors, hoods). Requires Read/Write enabled meshes.
Particles Tire smoke, exhaust fumes, dust trails, and sparks.
LOD Level-of-detail system that reduces mesh complexity for distant vehicles. Important for performance with many vehicles.
Audio Engine sounds, tire skid sounds, crash sounds, and wind noise.
Other Addons Networking integrations and other external systems.

Use Select All and Select None buttons to quickly toggle everything.

Tip about Damage: If you enable Damage, the wizard checks whether your mesh assets have Read/Write enabled. Mesh deformation requires writable meshes. If any meshes are not readable, the wizard offers to fix them automatically by enabling Read/Write on the mesh import settings and re-importing.

Step 6: Body Colliders

This step ensures your vehicle has physics colliders so it can interact with the environment (hit walls, land on the ground, etc.).

Pre-flight audit (V2.50.0+). Before the wizard accepts your existing collider setup, it runs RCCP_ModelColliderAudit over the vehicle hierarchy — including disabled GameObjects and components — and classifies every existing Collider it finds. The audit flags three categories of unsafe configuration:

Finding Why it's a problem
Trigger collider on the body A trigger doesn't participate in collision response, so the vehicle will pass through walls / ground on that part
Non-convex MeshCollider on the body Unity's Rigidbody physics requires convex MeshColliders. Non-convex ones only work on static objects and break vehicle collision
Collider on a wheel mesh Wheels are driven by WheelCollider. A second collider sitting on the wheel mesh fights the WheelCollider and produces erratic suspension

If any of these are present, the wizard pauses and shows a 3-button dialog summarising the findings (e.g., "2 triggers will be removed, 1 non-convex MeshCollider will be set to convex"):

Button What it does
Fix & Continue Auto-fixes every finding — removes triggers, flips non-convex MeshColliders to convex, removes wheel-mesh colliders — inside a single Undo group named "RCCP Auto-Fix Model Colliders", then proceeds with setup. One Ctrl+Z reverts the entire correction
Continue As-Is Skips the fixes and moves on. Use this when an audit finding is intentional (e.g., a trigger volume authored on purpose for a gameplay system)
Cancel Aborts the wizard with no changes

Vehicles with no audit findings are unaffected — the dialog never opens and the wizard moves straight to the body collider editor. Disabled colliders found by the audit are reported in the dialog for visibility but are never auto-stripped, since their disabled state usually signals deliberate authoring.

Body Colliders Wizard (V2.41.1+ live MeshCollider editor). The wizard then opens the per-mesh toggle list:

  1. Scans all MeshFilters in your vehicle hierarchy (excluding wheels)
  2. Sorts them by volume, largest first
  3. Auto-selects meshes larger than 10% of the biggest mesh — but only if they don't already have a MeshCollider, so re-opening the wizard cannot override your manual toggles
  4. Shows a live MeshColliders: N / total count at the top of the window

Each row's toggle reflects the current MeshCollider state of that GameObject, and flipping the toggle instantly adds or removes the component with Undo support — there is no separate "Add MeshColliders To Selected Parts" submit step. Each row also exposes a Ping button that highlights the GameObject in the Hierarchy so you can verify which mesh you're toggling. The window repaints at ~10 Hz so external edits (Inspector changes, undo/redo, other scripts adding or removing MeshColliders) reflect live.

Control Default Description
Convex MeshColliders On Applies the Convex flag only when adding a new collider. Existing colliders are never re-flagged by this toggle, so visiting the wizard cannot silently retune previously-tuned colliders
Add All / Remove All — Bulk-toggles every row on or off as a single Undo group (one Ctrl+Z reverts the bulk action)

If no body meshes are found: You can skip this step and add a collider manually later (a simple BoxCollider on the body is usually sufficient).

Important: Without at least one body collider, your vehicle will not collide with anything. Wheels have their own WheelColliders, but the body of the car needs a separate collider for wall hits, rollovers, and stacking.

Step 7: Finalize

This is the review and confirmation step. It displays a summary of everything you configured across all previous steps.

Summary sections (clickable): Each section header is clickable -- clicking it jumps you back to that step for editing.

Scene Setup: The wizard checks for: - RCCP Camera -- If missing, an "Add" button lets you place one instantly - Ground Collider -- If missing, an "Add" button creates a ground plane

UI Canvas toggle: If no RCCP UI Canvas is in the scene, you can opt to add one. The UI Canvas provides a ready-made dashboard with speedometer, RPM gauge, and control buttons.

Finishing:

  1. Review all settings in the summary
  2. Click Finish Setup
  3. The wizard runs final validation (wheels, suspension, engine, body colliders, mesh readability)
  4. If the scene is missing a camera or ground, you get a non-blocking warning with the option to continue anyway
  5. Body colliders are applied to selected mesh parts
  6. The vehicle is created with all chosen components
  7. If UI Canvas was selected, it is added to the scene
  8. A confirmation dialog appears: "Vehicle setup successfully completed!"

Your vehicle is now ready to drive. Press Play and test it.

Manual Vehicle Setup (Without Wizard)

If you prefer full control or have an unusual vehicle configuration, you can set everything up by hand. This is also useful for understanding what the wizard does behind the scenes.

Step-by-Step Manual Setup

  1. Drag your vehicle model into the scene from the Project panel

  2. Add RCCP_CarController to the vehicle root GameObject: - Select the vehicle root - Click Add Component > search for "RCCP Car Controller" - This automatically adds a Rigidbody component - Set the Rigidbody mass (default 1350 kg), drag (0.0025), angular drag (0.35), and interpolation to Interpolate

  3. Add the drivetrain components as child GameObjects. Each one is its own GameObject under the vehicle root:

Component GameObject Name Purpose
RCCP_Engine RCCP_Engine Produces torque based on RPM and throttle input
RCCP_Clutch RCCP_Clutch Connects/disconnects engine from gearbox
RCCP_Gearbox RCCP_Gearbox Multiplies torque through gear ratios
RCCP_Differential RCCP_Differential Splits power between left and right wheels on an axle
RCCP_Axles RCCP_Axles Manager that references all axle components

  1. Create axles as child GameObjects under the vehicle root and add RCCP_Axle to each: - Create "RCCP_Axle_Front" -- set isSteer = true, isBrake = true - Create "RCCP_Axle_Rear" -- set isBrake = true, isHandbrake = true - Assign wheel model transforms to leftWheelModel and rightWheelModel on each axle

  2. Connect the differential to the correct axle: - Select the RCCP_Differential component - Set connectedAxle to the axle that should receive power (rear axle for RWD, front for FWD) - For AWD, create a second Differential and connect each to a different axle

  3. Wire up drivetrain events (the engine-to-clutch-to-gearbox-to-differential chain): - Engine's output event connects to Clutch - Clutch's output event connects to Gearbox - Gearbox's output event connects to Differential - The wizard sets these up automatically; manually, you can use the Inspector to connect them

  4. Add optional components as needed:

RCCP_Input -- player input handling RCCP_AeroDynamics -- drag and downforce RCCP_Stability -- ABS, ESP, TCS RCCP_Audio -- engine and wheel sounds RCCP_Customizer -- paint, wheels, upgrades RCCP_Lights -- headlights, brake lights, indicators RCCP_Damage -- mesh deformation, detachable parts RCCP_Particles -- smoke, dust, sparks RCCP_LOD -- level of detail

Important: All RCCP components auto-register with the RCCP_CarController through the RCCP_Component.Register() method. You do not need to manually wire component references -- the car controller discovers them automatically.

Configuring Axles

After setup (wizard or manual), you can fine-tune each axle individually. Select any RCCP_Axle GameObject in the Hierarchy and use the Inspector.

Key Axle Settings

Setting Type Default Description
leftWheelModel Transform -- The visual mesh transform for the left wheel
rightWheelModel Transform -- The visual mesh transform for the right wheel
isPower bool false Whether this axle receives engine torque. Set automatically by the Differential's drive type -- do not set this manually.
isSteer bool false Whether this axle turns with steering input
isBrake bool false Whether this axle responds to brake input
isHandbrake bool false Whether this axle responds to handbrake input
antirollForce float 500 Anti-roll bar stiffness. Higher values reduce body roll in turns.
powerMultiplier float 1.0 Scales engine torque for this axle (-1 to 1). Negative inverts direction.
steerMultiplier float 1.0 Scales steering angle for this axle (-1 to 1). Use negative values for rear-wheel steering.
brakeMultiplier float 1.0 Scales brake force for this axle (0 to 1).
handbrakeMultiplier float 1.0 Scales handbrake force for this axle (0 to 1).

Typical Axle Configurations

Standard 4-wheel car:

Axle isSteer isBrake isHandbrake Notes
Front Yes Yes No Steering + front brakes
Rear No Yes Yes Rear brakes + handbrake

Rear-wheel steering (forklift, some sports cars):

Axle isSteer steerMultiplier Notes
Front Yes 1.0 Normal front steering
Rear Yes -0.15 Slight counter-steer at rear for stability

Drive Types Explained

The drive type determines which wheels receive engine power. It is configured on the RCCP_Differential component, which automatically sets isPower on the correct axles.

FWD (Front Wheel Drive)

Power goes to the front axle only. The front wheels both steer and drive.

RWD (Rear Wheel Drive)

Power goes to the rear axle only. The rear wheels drive while the front wheels steer.

AWD (All Wheel Drive)

Power goes to all axles. When you select AWD in the wizard, it creates two Differential components -- one connected to the front axle and one connected to the rear axle.

Common Setup Issues

If something goes wrong after setup, check these common problems first.

Vehicle flips or bounces on start

Cause: Wheel colliders are too close to or intersecting the ground at spawn time.

Fix: Increase the suspension distance or raise the vehicle slightly above the ground before pressing Play. Also check that the vehicle mass is reasonable for its size.

Wheels spinning in the wrong direction

Cause: Wheel model pivots are not centered or the model's local axis orientation is incorrect.

Fix: Check each wheel model in the Scene view. The pivot should be at the exact center of the wheel. If the model was exported with a different axis convention, you may need to re-export it or add a parent wrapper object.

Vehicle slides sideways

Cause: Wheel friction curves are set too low, or the wrong wheel type preset was selected.

Fix: Try changing the Wheel Type to "Stable" for more grip. You can also adjust wheel friction curves directly in Settings.

Vehicle is too slow

Cause: Max torque is too low, or the wrong axle has power.

Fix: Increase maxEngineTorque on the RCCP_Engine component. Also verify that the Differential is connected to the correct axle and that the driven axle's isPower is true.

No engine sound

Cause: RCCP_Audio component was not added, or audio clips are not assigned.

Fix: Make sure the vehicle has an RCCP_Audio component. Check that engine audio clips are configured in RCCP_Settings (go to Tools > BoneCracker Games > Realistic Car Controller Pro > Settings).

Vehicle falls through the ground

Cause: The scene has no ground collider, or the ground object is set as a trigger.

Fix: Add a Plane or Terrain with a Collider component. Make sure isTrigger is unchecked on the ground collider.

Meshes not readable warning

Cause: You enabled the Damage component, but the vehicle's mesh assets do not have Read/Write enabled in their import settings.

Fix: Select the mesh asset in the Project panel, open the Import Settings in the Inspector, enable Read/Write, and click Apply. The wizard can also do this automatically during setup.

Vehicle already has RCCP_CarController

Cause: You are trying to run the wizard on a vehicle that was already set up.

Fix: The wizard only works on fresh models. If you need to reconfigure, remove the RCCP_CarController and its child components first, then run the wizard again.

Next Steps

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Need help? See Troubleshooting