Stop fighting Wheel Colliders. Get real solid-axle articulation.
Simple Offroad Controller replaces Unity's WheelCollider with a raycast-based solid-axle system that gives you independent left/right wheel travel per axle, true differential locking, and a full tunable drivetrain, from the engine torque curve and gear ratios to spring rates, damper curves, and differential bias ratios.
Use the Auto-Configure wizard to go from meshes to a driving vehicle in under a minute, or build your hierarchy manually for full control.
Solid-Axle Physics
- Real articulation with independent left/right suspension travel per axle
- 4-ray wheel cast: center, left edge, right edge + forward-down step detection at 30°
- No WheelCollider, every ground interaction is custom raycast
- Spring-damper suspension with adjustable ride height, bump travel, droop, spring rate, and damping
- Anti-roll bar per axle with tunable stiffness
Drivetrain
- Engine simulation: multi-keyframe torque curve, rotational inertia, kinematic RPM coupling (engine speed driven by wheel speed through gear ratios), stall detection
- Automatic transmission: configurable gear ratios (4/5/6-speed presets), shift-up/down RPM thresholds, shift duration
- Differential models: Open, Locked, and Limited-Slip with configurable torque bias ratio
- Low range (4LO): torque-multiplying transfer case gear
- Toggleable 4WD: switch between 2WD and 4WD per axle on the fly
Tire Model
- Three-region lateral force curve (linear climb → gradual falloff → residual grip)
- Peak slip angle, max slip angle, and slide grip ratio, fully tunable per axle
- Friction circle coupling — throttle and brake forces interact with lateral grip
- Relaxation length, lateral force builds based on tire rolling distance, not a fixed timer, for realistic weight feel
- Speed-scaled force response (progressive turn-in at low speed, responsive at high speed)
Steering
- Max steer angle, sensitivity, smooth speed, and auto-return per axle
- High-speed reduction, reduces effective steering angle at speed for a forgiving arcade feel
- Reference speed control for reduction curve
- Invert steer per axle
Presets (One-Click Setup)
- Vehicle presets: Rock Crawler, Trail Rig, Overlander, Baja Racer — set weight, engine, transmission, suspension, differentials, and aerodynamics in one click
- Engine presets: V8 (diesel torque), V6 (balanced), I4 (high-RPM), I6 (broad flat curve)
- Transmission presets: 4, 5, or 6-speed gearboxes
Input
- New Input System (PlayerInput / .inputactions asset) via OffroadInputSystem — auto-added, no manual wiring
- OffroadInputDelegate for code-driven control: AI, testing, networked vehicles
- Max throttle slider for keyboard demos
- Auto reverse hold brake at standstill
AI Driver (BETA)
- Pure pursuit steering on a smooth Catmull-Rom spline path
- Curvature-based speed planning with approach braking and recovery zones
- Speed-adaptive lookahead distance
- Obstacle avoidance (optional, 5-ray fan)
- 4WD, low range, and e-brake support
- Auto-rebuilds path when waypoints move in the editor
Camera
- Forza-style follow camera with velocity look-ahead
- Mouse freelook with auto-recenter when driving
- Speed-based pushback and ground-height avoidance
- Multi-camera manager for switching (interior, chase, bumper, etc.)
Effects & Feedback
- Tire noise, velocity-based lateral slip with configurable volume/pitch curves and cooldown
- Dust particles on slip
- OffroadAudio, dual AudioSource with RPM-blended pitch/volume crossfade (idle + running), shift sounds, stall muting
- OffroadLightManager, 4-state cycle (Off → Main → HighBeam → Accessories) with automatic brake and reverse lights
- OffroadInfo (telemetry), real-time HUD overlay showing RPM, gear, speed, torque, compression, articulation, differential mode, and more
- Rich gizmo visualization, axle center, suspension travel, bump/droop stops, steer cone, spring zigzag
Vehicle Features
- Traction control (strength 0–1)
- Brake torque and e-brake per axle
- Parking hold with configurable speed threshold and hold force
- Aerodynamics, drag and downforce with speed-squared scaling
- Manual transmission mode support
What's Included
- 17 C# scripts (runtime + editor)
- Custom inspectors with preset buttons, sliders, and real-time gauges
- Auto-Configure editor wizard (body + wheel setup)
- Full documentation with setup guide, component reference, and tuning tips
- Demo scene with a fully configured vehicle
