update

Assets/frictions/High-Performance Road Tire.whfric

@@ -1,22 +0,0 @@
-{
-  "Longitudinal": {
-    "B": 18,
-    "C": 1.5,
-    "D": 1.5,
-    "E": 0.3
-  },
-  "Lateral": {
-    "B": 12,
-    "C": 1.3,
-    "D": 1.8,
-    "E": -1.8
-  },
-  "Aligning": {
-    "B": 2.8,
-    "C": 2.1,
-    "D": 0.1,
-    "E": -2.5
-  },
-  "__references": [],
-  "__version": 0
-}

Assets/frictions/aboba.whfric

@@ -1,22 +0,0 @@
-{
-  "Longitudinal": {
-    "B": 0,
-    "C": 1,
-    "D": 1,
-    "E": 0.3
-  },
-  "Lateral": {
-    "B": 1,
-    "C": 1,
-    "D": 1,
-    "E": 0.3
-  },
-  "Aligning": {
-    "B": 2.8,
-    "C": 2.1,
-    "D": 0.1,
-    "E": -2.5
-  },
-  "__references": [],
-  "__version": 0
-}

Assets/frictions/default.tire

@@ -0,0 +1,20 @@
+{
+  "Pacejka": {
+    "Lateral": {
+      "B": 12,
+      "C": 1.3,
+      "D": 1.8,
+      "E": -1.8
+    },
+    "Longitudinal": {
+      "B": 10.86,
+      "C": 2.15,
+      "D": 2,
+      "E": 0.992
+    }
+  },
+  "RollResistanceLin": 0.001,
+  "RollResistanceQuad": 1E-06,
+  "__references": [],
+  "__version": 0
+}

Code/Base/Powertrain/Clutch.cs

@@ -0,0 +1,49 @@
+using Sandbox;
+using System;
+
+namespace VeloX.Powertrain;
+
+public class Clutch : PowertrainComponent
+{
+	[Property] public override float Inertia { get; set; } = 0.002f;
+	[Property] public float SlipTorque { get; set; } = 1000f;
+
+	public float Pressing { get; set; } = 1; // todo
+
+	public override float QueryInertia()
+	{
+		if ( !HasOutput )
+			return Inertia;
+
+		return Inertia + Output.QueryInertia() * Pressing;
+	}
+
+	public override float QueryAngularVelocity( float angularVelocity )
+	{
+		this.angularVelocity = angularVelocity;
+
+		if ( !HasOutput )
+			return angularVelocity;
+
+
+		float outputW = Output.QueryAngularVelocity( angularVelocity ) * Pressing;
+		float inputW = angularVelocity * (1 - Pressing);
+
+		return outputW + inputW;
+	}
+
+
+	public override float ForwardStep( float torque, float inertia )
+	{
+		if ( !HasOutput )
+			return torque;
+
+		Torque = Math.Clamp( torque, -SlipTorque, SlipTorque );
+
+		Torque = torque * (1 - (1 - MathF.Pow( Pressing, 0.3f )));
+
+		float returnTorque = Output.ForwardStep( Torque, inertia * Pressing + Inertia ) * Pressing;
+
+		return Math.Clamp( returnTorque, -SlipTorque, SlipTorque );
+	}
+}

Code/Base/Powertrain/Differential/BaseDifferential.cs

@@ -0,0 +1,79 @@
+using Sandbox;
+using System;
+
+namespace VeloX.Powertrain;
+
+[Category( "VeloX/Powertrain/Differential" )]
+public abstract class BaseDifferential : PowertrainComponent
+{
+	[Property] public float FinalDrive { get; set; } = 3.392f;
+	[Property] public override float Inertia { get; set; } = 0.01f;
+	//[Property] public float CoastRamp { get; set; } = 1f;
+	//[Property] public float PowerRamp { get; set; } = 1f;
+	//[Property] public float Stiffness { get; set; } = 0.1f;
+	//[Property] public float SlipTorque { get; set; } = 0f;
+	//[Property] public float SteerLock { get; set; } = 45f;
+
+
+	/// <summary>
+	///     The PowertrainComponent this component will output to.
+	/// </summary>
+	[Property]
+	public PowertrainComponent OutputB
+	{
+		get => _outputb;
+		set
+		{
+			if ( value == this )
+			{
+				_outputb = null;
+				return;
+			}
+
+			_outputb = value;
+			if ( _outputb != null )
+				_outputb.Input = this;
+		}
+
+	}
+	private PowertrainComponent _outputb;
+
+	public override bool HasOutput => Output.IsValid() && OutputB.IsValid();
+
+	public override float QueryAngularVelocity( float angularVelocity )
+	{
+		this.angularVelocity = angularVelocity;
+
+		if ( !HasOutput )
+			return angularVelocity;
+
+		float aW = Output.QueryAngularVelocity( angularVelocity );
+		float bW = OutputB.QueryAngularVelocity( angularVelocity );
+
+		return (aW + bW) * FinalDrive * 0.5f;
+	}
+
+	public abstract void SplitTorque( float aW, float bW, float aI, float bI, out float tqA, out float tqB );
+
+	public override float ForwardStep( float torque, float inertia )
+	{
+		if ( !HasOutput )
+			return torque;
+
+		float aW = Output.QueryAngularVelocity( angularVelocity );
+		float bW = OutputB.QueryAngularVelocity( angularVelocity );
+
+		float aI = Output.QueryInertia();
+		float bI = OutputB.QueryInertia();
+
+		Torque = torque * FinalDrive;
+
+		SplitTorque( aW, bW, aI, bI, out float tqA, out float tqB );
+
+		tqA = Output.ForwardStep( tqA, inertia * 0.5f * MathF.Pow( FinalDrive, 2 ) + aI );
+		tqB = OutputB.ForwardStep( tqB, inertia * 0.5f * MathF.Pow( FinalDrive, 2 ) + bI );
+
+		return tqA + tqB;
+	}
+
+}

Code/Base/Powertrain/Differential/OpenDifferential.cs

@@ -0,0 +1,13 @@
+using Sandbox;
+
+namespace VeloX.Powertrain;
+
+public class OpenDifferential : BaseDifferential
+{
+	[Property] public float BiasAB { get; set; } = 0.5f;
+	public override void SplitTorque( float aW, float bW, float aI, float bI, out float tqA, out float tqB )
+	{
+		tqA = Torque * (1 - BiasAB);
+		tqB = Torque * BiasAB;
+	}
+}

Code/Base/Powertrain/Engine.cs

@@ -0,0 +1,109 @@
+using Sandbox;
+using System;
+
+namespace VeloX.Powertrain;
+
+public class Engine : PowertrainComponent
+{
+	[Property, Group( "Settings" )] public float IdleRPM { get; set; } = 900f;
+	[Property, Group( "Settings" )] public float MaxRPM { get; set; } = 7000f;
+	[Property, Group( "Settings" )] public override float Inertia { get; set; } = 0.151f;
+	[Property, Group( "Settings" )] public float LimiterDuration { get; set; } = 0.05f;
+	[Property, Group( "Settings" )] public Curve TorqueMap { get; set; }
+	[Property, Group( "Settings" )] public EngineStream Stream { get; set; }
+
+	[Sync] public float Throttle { get; internal set; }
+
+	[Property] public bool IsRedlining => !limiterTimer;
+	[Property] public float RPMPercent => Math.Clamp( (RPM - IdleRPM) / (MaxRPM - IdleRPM), 0, 1 );
+
+	private float masterThrottle;
+	private TimeUntil limiterTimer;
+	private float finalTorque;
+
+	private EngineStreamPlayer StreamPlayer;
+	public float[] friction = [15.438f, 2.387f, 0.7958f];
+
+	protected override void OnStart()
+	{
+		base.OnStart();
+
+		StreamPlayer = new( Stream );
+	}
+
+	public float GetFrictionTorque( float throttle, float rpm )
+	{
+		float s = rpm < 0 ? -1f : 1f;
+		float r = s * rpm * 0.001f;
+		float f = friction[0] + friction[1] * r + friction[2] * r * r;
+		return -s * f * (1 - throttle);
+	}
+	private float GenerateTorque()
+	{
+		float throttle = Throttle;
+		float rpm = RPM;
+		float friction = GetFrictionTorque( throttle, rpm );
+
+		float maxInitialTorque = TorqueMap.Evaluate( RPMPercent ) - friction;
+		float idleFadeStart = Math.Clamp( MathX.Remap( rpm, IdleRPM - 300, IdleRPM, 1, 0 ), 0, 1 );
+		float idleFadeEnd = Math.Clamp( MathX.Remap( rpm, IdleRPM, IdleRPM + 600, 1, 0 ), 0, 1 );
+		float additionalEnergySupply = idleFadeEnd * (-friction / maxInitialTorque) + idleFadeStart;
+
+
+		if ( rpm > MaxRPM )
+		{
+			throttle = 0;
+			limiterTimer = LimiterDuration;
+		}
+		else if ( !limiterTimer )
+			throttle = 0;
+
+		masterThrottle = Math.Clamp( additionalEnergySupply + throttle, 0, 1 );
+
+		float realInitialTorque = maxInitialTorque * masterThrottle;
+		Torque = realInitialTorque + friction;
+
+		return Torque;
+	}
+
+	public override float ForwardStep( float _, float __ )
+	{
+		if ( !HasOutput )
+		{
+			angularVelocity += GenerateTorque() / Inertia * Time.Delta;
+			angularVelocity = Math.Max( angularVelocity, 0 );
+			return 0;
+		}
+		float outputInertia = Output.QueryInertia();
+		float inertiaSum = Inertia + outputInertia;
+		float outputW = Output.QueryAngularVelocity( angularVelocity );
+
+		float targetW = Inertia / inertiaSum * angularVelocity + outputInertia / inertiaSum * outputW;
+		float generatedTorque = GenerateTorque();
+		float reactTorque = (targetW - angularVelocity) * Inertia / Time.Delta;
+		float returnedTorque = Output.ForwardStep( generatedTorque - reactTorque, Inertia );
+
+		finalTorque = generatedTorque + reactTorque + returnedTorque;
+		angularVelocity += finalTorque / inertiaSum * Time.Delta;
+		angularVelocity = Math.Max( angularVelocity, 0 );
+
+		UpdateStream();
+
+		return finalTorque;
+	}
+
+	private void UpdateStream()
+	{
+		if ( StreamPlayer is null )
+			return;
+
+		StreamPlayer.Throttle = Throttle;
+		StreamPlayer.RPMPercent = RPMPercent;
+		StreamPlayer.EngineState = EngineState.Running;
+		StreamPlayer.IsRedlining = IsRedlining;
+
+		StreamPlayer.Update( Time.Delta, WorldPosition );
+
+	}
+
+}

Code/Base/Powertrain/Gearbox/BaseGearbox.cs

@@ -0,0 +1,45 @@
+using Sandbox;
+using System;
+
+namespace VeloX.Powertrain;
+
+[Category( "VeloX/Powertrain/Gearbox" )]
+public abstract class BaseGearbox : PowertrainComponent
+{
+	[Property] public override float Inertia { get; set; } = 0.01f;
+
+	protected float ratio;
+
+	public override float QueryInertia()
+	{
+		if ( !HasOutput || ratio == 0 )
+			return Inertia;
+
+		return Inertia + Output.QueryInertia() / MathF.Pow( ratio, 2 );
+	}
+
+	public override float QueryAngularVelocity( float angularVelocity )
+	{
+		this.angularVelocity = angularVelocity;
+		if ( !HasOutput || ratio == 0 )
+			return angularVelocity;
+
+		return Output.QueryAngularVelocity( angularVelocity ) * ratio;
+	}
+
+	public override float ForwardStep( float torque, float inertia )
+	{
+		Torque = torque * ratio;
+
+		if ( !HasOutput )
+			return torque;
+
+		if ( ratio == 0 )
+		{
+			Output.ForwardStep( 0, Inertia * 0.5f );
+			return torque;
+		}
+
+		return Output.ForwardStep( Torque, (inertia + Inertia) * MathF.Pow( ratio, 2 ) ) / ratio;
+	}
+}

Code/Base/Powertrain/Gearbox/ManualGearbox.cs

@@ -0,0 +1,52 @@
+using Sandbox;
+
+namespace VeloX.Powertrain;
+
+public class ManualGearbox : BaseGearbox
+{
+	[Property] public float[] Ratios { get; set; } = [3.626f, 2.200f, 1.541f, 1.213f, 1.000f, 0.767f];
+	[Property] public float Reverse { get; set; } = 3.4f;
+	[Property, InputAction] public string ForwardAction { get; set; } = "Attack1";
+	[Property, InputAction] public string BackwardAction { get; set; } = "Attack2";
+
+	private int gear;
+
+	protected void SetGear( int gear )
+	{
+		if ( gear < -1 || gear >= Ratios.Length )
+			return;
+		this.gear = gear;
+
+		RecalcRatio();
+	}
+
+	private void RecalcRatio()
+	{
+		if ( gear == -1 )
+			ratio = -Reverse;
+		else if ( gear == 0 )
+			ratio = 0;
+		else
+			ratio = Ratios[gear - 1];
+	}
+
+	public void Shift( int dir )
+	{
+		SetGear( gear + dir );
+	}
+
+	private void InputResolve()
+	{
+		if ( Sandbox.Input.Pressed( ForwardAction ) )
+			Shift( 1 );
+		else if ( Sandbox.Input.Pressed( BackwardAction ) )
+			Shift( -1 );
+	}
+
+	public override float ForwardStep( float torque, float inertia )
+	{
+		InputResolve();
+
+		return base.ForwardStep( torque, inertia );
+	}
+}

Code/Base/Powertrain/PowerWheel.cs

@@ -0,0 +1,34 @@
+using Sandbox;
+using System;
+
+namespace VeloX.Powertrain;
+
+public class PowerWheel : PowertrainComponent
+{
+	[Property] public VeloXWheel Wheel { get; set; }
+
+	public override float QueryInertia()
+	{
+		float dtScale = Math.Clamp( Time.Delta, 0.01f, 0.05f ) / 0.005f;
+		return Wheel.BaseInertia * dtScale;
+	}
+
+	public override float QueryAngularVelocity( float angularVelocity )
+	{
+		return Wheel.AngularVelocity;
+	}
+
+	public override float ForwardStep( float torque, float inertia )
+	{
+		Wheel.AutoPhysics = false;
+		Wheel.Torque = torque;
+		Wheel.Brake = Vehicle.Brake;
+		Inertia = Wheel.BaseInertia + inertia;
+		Wheel.Inertia = inertia;
+		Wheel.DoPhysics( Vehicle );
+
+		angularVelocity = Wheel.AngularVelocity;
+
+		return Wheel.CounterTorque;
+	}
+}

Code/Base/Powertrain/PowertrainComponent.cs

@@ -0,0 +1,100 @@
+using Sandbox;
+using System;
+
+namespace VeloX.Powertrain;
+
+public abstract class PowertrainComponent : Component
+{
+
+	protected override void OnAwake()
+	{
+		Vehicle ??= Components.Get<VeloXBase>( FindMode.EverythingInSelfAndAncestors );
+	}
+
+	public const float RAD_TO_RPM = 60f / MathF.Tau;
+	public const float RPM_TO_RAD = 1 / (60 / MathF.Tau);
+	public const float UNITS_PER_METER = 39.37f;
+	public const float UNITS_TO_METERS = 0.01905f;
+	public const float KG_TO_N = 9.80665f;
+	public const float KG_TO_KN = 0.00980665f;
+
+	[Property] public VeloXBase Vehicle { get; set; }
+	[Property] public virtual float Inertia { get; set; } = 0.02f;
+
+
+	/// <summary>
+	///     Input component. Set automatically.
+	/// </summary>
+	[Property]
+	public PowertrainComponent Input
+	{
+		get => _input;
+		set
+		{
+			if ( value == null || value == this )
+			{
+				_input = null;
+				return;
+			}
+
+			_input = value;
+		}
+	}
+
+	private PowertrainComponent _input;
+	public int InputNameHash;
+
+	/// <summary>
+	///     The PowertrainComponent this component will output to.
+	/// </summary>
+	[Property]
+	public PowertrainComponent Output
+	{
+		get => _output;
+		set
+		{
+			if ( value == this )
+			{
+				_output = null;
+				return;
+			}
+
+			_output = value;
+			if ( _output != null )
+				_output.Input = this;
+		}
+
+	}
+	private PowertrainComponent _output;
+
+	public float RPM => angularVelocity * RAD_TO_RPM;
+
+	protected float angularVelocity;
+	protected float Torque;
+
+	public virtual bool HasOutput => Output.IsValid();
+
+	public virtual float QueryInertia()
+	{
+		if ( !HasOutput )
+			return Inertia;
+
+		return Inertia + Output.QueryInertia();
+	}
+
+	public virtual float QueryAngularVelocity( float angularVelocity )
+	{
+		if ( !HasOutput )
+			return angularVelocity;
+
+		return Output.QueryAngularVelocity( angularVelocity );
+	}
+
+	public virtual float ForwardStep( float torque, float inertia )
+	{
+		if ( !HasOutput )
+			return Torque;
+
+		return Output.ForwardStep( Torque, inertia + Inertia );
+	}
+}

Code/Base/VeloXBase.Phys.cs

@@ -1,4 +1,5 @@
 using Sandbox;
+using System;
 
 namespace VeloX;
 
@@ -17,13 +18,22 @@ public abstract partial class VeloXBase
 		angForce.y = angVel.y * drag.y * mass;
 		angForce.z = angVel.z * drag.z * mass;
 
-
 		if ( Wheels.Count > 0 )
-		{
-
-			var dt = Time.Delta;
 			foreach ( var v in Wheels )
-				v.DoPhysics( this, in dt );
+				if ( v.AutoPhysics ) v.DoPhysics( this );
+
+		var totalSpeed = TotalSpeed + Math.Abs( Body.AngularVelocity.z );
+
+		var factor = 1 - Math.Clamp( totalSpeed / 30, 0, 1 );
+
+		if ( factor > 0.1f )
+		{
+			var vel = Body.Velocity;
+
+			var rt = WorldRotation.Right;
+
+			var force = rt.Dot( vel ) / Time.Delta * mass * factor * rt;
+			Body.ApplyForce( -force );
 		}
 
 		Body.ApplyTorque( angForce );

Code/Base/VeloXBase.cs

@@ -15,7 +15,7 @@ public abstract partial class VeloXBase : Component
 	[Property, Group( "Components" )] public Rigidbody Body { get; protected set; }
 	[Property, Group( "Components" )] public Collider Collider { get; protected set; }
 
-	[Sync] public Angles SteerAngle { get; set; }
+	[Sync( SyncFlags.Interpolate )] public Angles SteerAngle { get; set; }
 
 	public Vector3 LocalVelocity;
 	public float ForwardSpeed;

Code/Base/Wheel/FrictionPreset.cs

@@ -1,16 +0,0 @@
-using System;
-
-namespace VeloX;
-public class FrictionPreset
-{
-	public float B { get; set; } = 10.86f;
-	public float C { get; set; } = 2.15f;
-	public float D { get; set; } = 0.933f;
-	public float E { get; set; } = 0.992f;
-	public float Evaluate( float slip )
-	{
-		var t = Math.Abs( slip );
-
-		return D * MathF.Sin( C * MathF.Atan( B * t - E * (B * t - MathF.Atan( B * t )) ) );
-	}
-}

Code/Base/Wheel/Pacejka.cs

@@ -0,0 +1,43 @@
+using Sandbox;
+using Sandbox.Services;
+using System;
+using System.Threading;
+
+namespace VeloX;
+public class Pacejka
+{
+	public class PacejkaPreset
+	{
+		[KeyProperty] public float B { get; set; } = 10.86f;
+		[KeyProperty] public float C { get; set; } = 2.15f;
+		[KeyProperty] public float D { get; set; } = 0.933f;
+		[KeyProperty] public float E { get; set; } = 0.992f;
+
+		public float Evaluate( float slip ) => D * MathF.Sin( C * MathF.Atan( B * slip - E * (B * slip - MathF.Atan( B * slip )) ) );
+
+		public float GetPeakSlip()
+		{
+			float peakSlip = -1;
+			float yMax = 0;
+
+			for ( float i = 0; i < 1f; i += 0.01f )
+			{
+				float y = Evaluate( i );
+				if ( y > yMax )
+				{
+					yMax = y;
+					peakSlip = i;
+				}
+			}
+
+			return peakSlip;
+		}
+
+	}
+
+	public PacejkaPreset Lateral { get; set; } = new();
+	public PacejkaPreset Longitudinal { get; set; } = new();
+
+	public float PacejkaFx( float slip ) => Longitudinal.Evaluate( slip );
+	public float PacejkaFy( float slip ) => Lateral.Evaluate( slip );
+}

Code/Base/Wheel/Suspension/BasicSuspension.cs

@@ -0,0 +1,18 @@
+namespace VeloX;
+
+public class BasicSuspension
+{
+	private readonly Hinge Hinge;
+
+	public BasicSuspension( Vector3 wheel, Vector3 hingeBody, Vector3 hingeWheel )
+	{
+		Vector3 hingePoint = wheel - (hingeWheel - hingeBody);
+		Hinge = new Hinge( hingePoint, hingeWheel - hingeBody );
+	}
+
+	public virtual void GetWheelTransform( float travel, out Rotation rotation, out Vector3 position )
+	{
+		rotation = Rotation.Identity;
+		position = Hinge.Rotate( travel );
+	}
+}

Code/Base/Wheel/Suspension/Hinge.cs

@@ -0,0 +1,26 @@
+using System;
+
+namespace VeloX;
+
+internal readonly struct Hinge( Vector3 hinge_anchor, Vector3 hinge_arm )
+{
+	[Description( "the point that the wheels are rotated around as the suspension compresses" )]
+	public readonly Vector3 Anchor = hinge_anchor;
+
+	[Description( "anchor to wheel vector" )]
+	public readonly Vector3 Arm = hinge_arm;
+
+	[Description( "arm length squared" )]
+	public readonly float LengthSquared = hinge_arm.Dot( hinge_arm );
+
+	[Description( "1 / arm length in hinge axis normal plane" )]
+	public readonly float NormXY = 1 / MathF.Sqrt( hinge_arm.x * hinge_arm.x + hinge_arm.y * hinge_arm.y );
+
+	public readonly Vector3 Rotate( float travel )
+	{
+		float z = Arm.z + travel;
+		float lengthSq = MathF.Max( LengthSquared - z * z, 0.0f );
+		float nxy = NormXY * MathF.Sqrt( lengthSq );
+		return Anchor + new Vector3( Arm.x * nxy, Arm.y * nxy, z );
+	}
+}

Code/Base/Wheel/Suspension/MacPhersonSuspension.cs

@@ -0,0 +1,32 @@
+using Sandbox;
+using System;
+
+namespace VeloX;
+public class MacPhersonSuspension
+{
+	public readonly Vector3 WheelOffset;
+	public readonly Vector3 UprightTop;
+	public readonly Vector3 UprightAxis;
+	private readonly Hinge Hinge;
+
+	public MacPhersonSuspension( Vector3 wheel, Vector3 strutBody, Vector3 strutWheel, Vector3 hingeBody )
+	{
+		WheelOffset = wheel - strutWheel;
+		UprightTop = strutBody;
+		UprightAxis = (strutBody - strutWheel).Normal;
+		Hinge = new( hingeBody, strutWheel - hingeBody );
+	}
+
+	public void GetWheelTransform( float travel, out Rotation rotation, out Vector3 position )
+	{
+		Vector3 hingeEnd = Hinge.Rotate( travel );
+		Vector3 uprightAxisNew = (UprightTop - hingeEnd).Normal;
+
+		rotation = Rotation.FromAxis(
+			Vector3.Cross( UprightAxis, uprightAxisNew ),
+			MathF.Acos( Vector3.Dot( UprightAxis, uprightAxisNew ) ).RadianToDegree()
+		);
+
+		position = hingeEnd + WheelOffset.Transform( rotation );
+	}
+}

Code/Base/Wheel/TirePreset.cs

@@ -0,0 +1,60 @@
+using Sandbox;
+using System;
+
+namespace VeloX;
+
+
+[GameResource( "Wheel Friction", "tire", "Wheel Friction", Category = "VeloX", Icon = "radio_button_checked" )]
+public class TirePreset : GameResource
+{
+
+	[Property] public Pacejka Pacejka { get; set; }
+
+	public float RollResistanceLin { get; set; } = 1E-3f;
+	public float RollResistanceQuad { get; set; } = 1E-6f;
+
+	public float GetRollingResistance( float velocity, float resistance_factor )
+	{   // surface influence on rolling resistance
+		float resistance = resistance_factor * RollResistanceLin;
+
+		// heat due to tire deformation increases rolling resistance
+		// approximate by quadratic function
+		resistance += velocity * velocity * RollResistanceQuad;
+
+		return resistance;
+	}
+
+	public static void ComputeSlip( float lon_velocity, float lat_velocity, float rot_velocity, float wheel_radius, out float slip_ratio, out float slip_angle )
+	{
+		var abs_lon = Math.Max( MathF.Abs( lon_velocity ), 1e-3f );
+
+		slip_ratio = lon_velocity - rot_velocity * wheel_radius;
+
+		if ( abs_lon >= 0.005f )
+			slip_ratio /= abs_lon;
+		else
+			slip_ratio *= abs_lon;
+
+		if ( abs_lon >= 0.5f )
+			slip_angle = MathF.Atan2( -lat_velocity, abs_lon ).RadianToDegree() / 50f;
+		else
+			slip_angle = -lat_velocity * (0.01f / Time.Delta);
+
+		slip_ratio = Math.Clamp( slip_ratio, -1, 1 );
+		slip_angle = Math.Clamp( slip_angle, -1, 1 );
+
+	}
+
+	/// approximate asin(x) = x + x^3/6 for +-18 deg range
+	public static float ComputeCamberAngle( float sin_camber )
+	{
+		float sc = Math.Clamp( sin_camber, -0.3f, 0.3f );
+		return ((1 / 6.0f) * (sc * sc) + 1) * sc;
+	}
+
+	public static float ComputeCamberVelocity( float sa, float vx )
+	{
+		float tansa = (1 / 3.0f * (sa * sa) + 1) * sa;
+		return tansa * vx;
+	}
+}

Code/Base/Wheel/VeloXWheel.Sound.cs

@@ -0,0 +1,28 @@
+using Sandbox;
+using System;
+
+namespace VeloX;
+
+
+public partial class VeloXWheel : Component
+{
+	private RealTimeUntil expandSoundCD;
+	private RealTimeUntil contractSoundCD;
+	private void DoSuspensionSounds( VeloXBase vehicle, float change )
+	{
+		if ( change > 0.1f && expandSoundCD )
+		{
+			expandSoundCD = 0.3f;
+			var sound = Sound.Play( vehicle.SuspensionUpSound, WorldPosition );
+			sound.Volume = Math.Clamp( Math.Abs( change ) * 5f, 0, 0.5f );
+		}
+
+		if ( change < -0.1f && contractSoundCD )
+		{
+			contractSoundCD = 0.3f;
+			change = MathF.Abs( change );
+			var sound = Sound.Play( change > 0.3f ? vehicle.SuspensionHeavySound : vehicle.SuspensionDownSound, WorldPosition );
+			sound.Volume = Math.Clamp( change * 5f, 0, 1 );
+		}
+	}
+}

Code/Base/Wheel/VeloXWheel.cs

@@ -1,11 +1,16 @@
 using Sandbox;
+using Sandbox.Rendering;
+using Sandbox.Services;
 using Sandbox.UI;
 using System;
-using System.Buffers.Text;
+using System.Collections.Specialized;
+using System.Diagnostics.Metrics;
 using System.Numerics;
-using System.Runtime.Intrinsics.Arm;
 using System.Text.RegularExpressions;
 using System.Threading;
+using static Sandbox.CameraComponent;
+using static Sandbox.Package;
+using static Sandbox.SkinnedModelRenderer;
 
 namespace VeloX;
 
@@ -18,18 +23,10 @@ public partial class VeloXWheel : Component
 	[Property] public float Mass { get; set; } = 20;
 	[Property] public float RollingResistance { get; set; } = 20;
 	[Property] public float SlipCircleShape { get; set; } = 1.05f;
-
+	[Property] public TirePreset TirePreset { get; set; }
-	public FrictionPreset LongitudinalFrictionPreset => WheelFriction.Longitudinal;
-	public FrictionPreset LateralFrictionPreset => WheelFriction.Lateral;
-	public FrictionPreset AligningFrictionPreset => WheelFriction.Aligning;
-
-	[Property] public WheelFriction WheelFriction { get; set; }
-
-
 	[Property] public float Width { get; set; } = 6;
-	[Sync] public float SideSlip { get; private set; }
+	public float SideSlip { get; private set; }
-	[Sync] public float ForwardSlip { get; private set; }
+	public float ForwardSlip { get; private set; }
-	[Sync, Range( 0, 1 )] public float BrakePower { get; set; }
 	[Sync] public float Torque { get; set; }
 	[Sync, Range( 0, 1 )] public float Brake { get; set; }
 	[Property] float BrakePowerMax { get; set; } = 3000;
@@ -38,14 +35,19 @@ public partial class VeloXWheel : Component
 	[Property] public float CasterAngle { get; set; } = 7; // todo
 	[Property] public float CamberAngle { get; set; } = -3;
 	[Property] public float ToeAngle { get; set; } = 0.5f;
+	[Property] public float Ackermann { get; set; } = 0;
 
 	[Property, Group( "Suspension" )] float SuspensionLength { get; set; } = 10;
 	[Property, Group( "Suspension" )] float SpringStrength { get; set; } = 800;
 	[Property, Group( "Suspension" )] float SpringDamper { get; set; } = 3000;
 
+	[Property] public bool AutoPhysics { get; set; } = true;
+
 	public float Spin { get; private set; }
 
-	public float RPM { get => angularVelocity * 60f / MathF.Tau; set => angularVelocity = value / (60 / MathF.Tau); }
+	public float RPM { get => angularVelocity * 30f / MathF.PI; set => angularVelocity = value / (30f / MathF.PI); }
+	public float AngularVelocity { get => angularVelocity; set => angularVelocity = value; }
+
 	internal float DistributionFactor { get; set; }
 
 	private Vector3 StartPos { get; set; }
@@ -58,20 +60,24 @@ public partial class VeloXWheel : Component
 	private float angularVelocity;
 	private float load;
 	private float lastFraction;
-	private RealTimeUntil expandSoundCD;
-	private RealTimeUntil contractSoundCD;
 
 	private Vector3 contactPos;
 	private Vector3 forward;
 	private Vector3 right;
 	private Vector3 up;
 
-	private Friction forwardFriction;
+	private float forwardFriction;
-	private Friction sideFriction;
+	private float sideFriction;
 	private Vector3 force;
+	public float CounterTorque { get; private set; }
+
+	internal float BaseInertia => 0.5f * Mass * MathF.Pow( Radius.InchToMeter(), 2 );
+	public float Inertia
+	{
+		get => BaseInertia + inertia;
+		set => inertia = value;
+	}
 
-	private float BaseInertia => 0.5f * Mass * MathF.Pow( Radius.InchToMeter(), 2 );
-	private float Inertia => BaseInertia;
 
 	protected override void OnAwake()
 	{
@@ -80,24 +86,6 @@ public partial class VeloXWheel : Component
 			StartPos = LocalPosition;
 	}
 
-	private void DoSuspensionSounds( VeloXBase vehicle, float change )
-	{
-		if ( change > 0.1f && expandSoundCD )
-		{
-			expandSoundCD = 0.3f;
-			var sound = Sound.Play( vehicle.SuspensionUpSound, WorldPosition );
-			sound.Volume = Math.Clamp( Math.Abs( change ) * 5f, 0, 0.5f );
-		}
-
-		if ( change < -0.1f && contractSoundCD )
-		{
-			contractSoundCD = 0.3f;
-			change = MathF.Abs( change );
-			var sound = Sound.Play( change > 0.3f ? vehicle.SuspensionHeavySound : vehicle.SuspensionDownSound, WorldPosition );
-			sound.Volume = Math.Clamp( change * 5f, 0, 1 );
-		}
-	}
-
 	internal void Update( VeloXBase vehicle, in float dt )
 	{
 		UpdateVisuals( vehicle, dt );
@@ -105,94 +93,102 @@ public partial class VeloXWheel : Component
 
 	private void UpdateVisuals( VeloXBase vehicle, in float dt )
 	{
-		var entityAngles = vehicle.WorldRotation;
+		Spin -= angularVelocity.RadianToDegree() * dt;
-
+		WorldRotation = vehicle.WorldTransform.RotationToWorld( GetSteer( vehicle.SteerAngle.yaw ) ) * Rotation.FromAxis( Vector3.Right, Spin );
-		Spin -= angularVelocity.MeterToInch() * dt;
-
-
-		var steerRotated = entityAngles.RotateAroundAxis( Vector3.Up, vehicle.SteerAngle.yaw * SteerMultiplier + ToeAngle );
-		var camberRotated = steerRotated.RotateAroundAxis( Vector3.Forward, -CamberAngle );
-		var angularVelocityRotated = camberRotated.RotateAroundAxis( Vector3.Right, Spin );
-
-		WorldRotation = angularVelocityRotated;
-
 	}
 
-	private (float, float, float, float) StepLongitudinal( float Vx, float Lc, float kFx, float kSx, float dt )
+	private Rotation GetSteer( float steer )
 	{
-		float Tm = Torque;
-		float Tb = Brake * BrakePowerMax + RollingResistance;
-		float R = Radius.InchToMeter();
-		float I = Inertia;
 
-		float Winit = angularVelocity;
+		float angle = (-steer * SteerMultiplier).DegreeToRadian();
-		float W = angularVelocity;
 
-		float VxAbs = MathF.Abs( Vx );
+		float t = MathF.Tan( (MathF.PI / 2) - angle ) - Ackermann;
+		float steering_angle = MathF.CopySign( float.Pi / 2, t ) - MathF.Atan( t );
+		var steering_axis = Vector3.Up * MathF.Cos( -CasterAngle.DegreeToRadian() ) +
+			Vector3.Right * MathF.Sin( -CasterAngle.DegreeToRadian() );
+
+		return Rotation.FromAxis( Vector3.Forward, -CamberAngle ) * Rotation.FromAxis( steering_axis, steering_angle.RadianToDegree() );
+	}
+
+
+	private static float GetLongitudinalLoadCoefficient( float load ) => 11000 * (1 - MathF.Exp( -0.00014f * load ));
+	private static float GetLateralLoadCoefficient( float load ) => 18000 * (1 - MathF.Exp( -0.0001f * load ));
+	private float inertia;
+
+
+	private (float, float, float, float) StepLongitudinal( float Tm, float Tb, float Vx, float W, float Lc, float R, float I )
+	{
+		float wInit = W;
+		float vxAbs = Math.Abs( Vx );
 		float Sx;
-		if ( VxAbs >= 0.1f )
+		if ( Lc < 0.01f )
-			Sx = (Vx - W * R) / VxAbs;
+		{
-
+			Sx = 0;
+		}
+		else if ( vxAbs >= 0.01f )
+		{
+			Sx = (W * R - Vx) / vxAbs;
+		}
 		else
-			Sx = (Vx - W * R) * 0.6f;
+		{
+			Sx = (W * R - Vx) * 0.6f;
+		}
 
-		Sx = Math.Clamp( Sx * kSx, -1, 1 );
+		Sx = Math.Clamp( Sx, -1, 1 );
 
-		W += Tm / I * dt;
+		W += Tm / I * Time.Delta;
 
 		Tb *= W > 0 ? -1 : 1;
 
-		float TbCap = MathF.Abs( W ) * I / dt;
+		float tbCap = Math.Abs( W ) * I / Time.Delta;
-		float Tbr = MathF.Abs( Tb ) - MathF.Abs( TbCap );
+		float tbr = Math.Abs( Tb ) - Math.Abs( tbCap );
-		Tbr = MathF.Max( Tbr, 0 );
+		tbr = Math.Max( tbr, 0 );
-		Tb = Math.Clamp( Tb, -TbCap, TbCap );
-		W += Tb / I * dt;
 
-		float maxTorque = LongitudinalFrictionPreset.Evaluate( Sx ) * Lc * kFx;
+		Tb = Math.Clamp( Tb, -tbCap, tbCap );
 
-		float errorTorque = (W - Vx / R) * I / dt;
+		W += Tb / I * Time.Delta;
 
-		float surfaceTorque = MathX.Clamp( errorTorque, -maxTorque, maxTorque );
+		float maxTorque = TirePreset.Pacejka.PacejkaFx( Math.Abs( Sx ) ) * Lc * R;
 
-		W -= surfaceTorque / I * dt;
+		float errorTorque = (W - Vx / R) * I / Time.Delta;
+		float surfaceTorque = Math.Clamp( errorTorque, -maxTorque, maxTorque );
 
+		W -= surfaceTorque / I * Time.Delta;
 		float Fx = surfaceTorque / R;
 
+		tbr *= (W > 0 ? -1 : 1);
+		float TbCap2 = Math.Abs( W ) * I / Time.Delta;
+		float Tb2 = Math.Clamp( tbr, -TbCap2, TbCap2 );
+		W += Tb2 / I * Time.Delta;
 
-		Tbr *= W > 0 ? -1 : 1;
+		float deltaOmegaTorque = (W - wInit) * I / Time.Delta;
-		float TbCap2 = MathF.Abs( W ) * I / dt;
-
-		float Tb2 = Math.Clamp( Tbr, -TbCap2, TbCap2 );
-
-		W += Tb2 / I * dt;
-
-		float deltaOmegaTorque = (W - Winit) * I / dt;
-
 		float Tcnt = -surfaceTorque + Tb + Tb2 - deltaOmegaTorque;
-		if ( Lc < 0.001f )
-			Sx = 0;
 
 		return (W, Sx, Fx, Tcnt);
 	}
 
-	private (float, float) StepLateral( float Vx, float Vy, float Lc, float kFy, float kSy, float dt )
+	private void StepLateral( float Vx, float Vy, float Lc, out float Sy, out float Fy )
 	{
-		float VxAbs = MathF.Abs( Vx );
+		float VxAbs = Math.Abs( Vx );
-		float Sy;
 
-		if ( VxAbs > 0.1f )
+		if ( Lc < 0.01f )
-			Sy = MathF.Atan( Vy / VxAbs ).RadianToDegree() * 0.01111f;
+		{
-		else
-			Sy = Vy * (0.003f / dt);
-
-
-		Sy *= kSy * 0.95f;
-		Sy = Math.Clamp( Sy * kSy, -1, 1 );
-		float Fy = -MathF.Sign( Sy ) * LateralFrictionPreset.Evaluate( Sy ) * Lc * kFy;
-		if ( Lc < 0.0001f )
 			Sy = 0;
+		}
+		else if ( VxAbs > 0.1f )
+		{
 
-		return (Sy, Fy);
+			Sy = MathX.RadianToDegree( MathF.Atan( Vy / VxAbs ) ) / 50;
+		}
+		else
+		{
+
+			Sy = Vy * (0.003f / Time.Delta);
+		}
+
+		Sy = Math.Clamp( Sy, -1, 1 );
+		float slipSign = Sy < 0 ? -1 : 1;
+		Fy = -slipSign * TirePreset.Pacejka.PacejkaFy( Math.Abs( Sy ) ) * Lc;
 	}
 
 	private void SlipCircle( float Sx, float Sy, float Fx, ref float Fy )
@@ -200,39 +196,23 @@ public partial class VeloXWheel : Component
 		float SxAbs = Math.Abs( Sx );
 		if ( SxAbs > 0.01f )
 		{
-
 			float SxClamped = Math.Clamp( Sx, -1, 1 );
-
 			float SyClamped = Math.Clamp( Sy, -1, 1 );
-
+			Vector2 combinedSlip = new( SxClamped * 1.05f, SyClamped );
-			Vector2 combinedSlip = new(
-				SxClamped * SlipCircleShape,
-				SyClamped
-			);
-
 			Vector2 slipDir = combinedSlip.Normal;
 
 			float F = MathF.Sqrt( Fx * Fx + Fy * Fy );
+			float absSlipDirY = Math.Abs( slipDir.y );
 
-			float absSlipDirY = MathF.Abs( slipDir.y );
+			Fy = F * absSlipDirY * (Fy < 0 ? -1 : 1);
-
-			Fy = F * absSlipDirY * MathF.Sign( Fy );
 		}
 	}
 
-
+	public void DoPhysics( VeloXBase vehicle )
-	private static float GetLongitudinalLoadCoefficient( float load ) => 11000 * (1 - MathF.Exp( -0.00014f * load ));
-	private static float GetLateralLoadCoefficient( float load ) => 18000 * (1 - MathF.Exp( -0.0001f * load ));
-
-	public void DoPhysics( VeloXBase vehicle, in float dt )
 	{
 		var pos = vehicle.WorldTransform.PointToWorld( StartPos );
 
-		var ang = vehicle.WorldTransform.RotationToWorld( vehicle.SteerAngle * SteerMultiplier );
+		var ang = vehicle.WorldTransform.RotationToWorld( GetSteer( vehicle.SteerAngle.yaw ) );
-
-		forward = ang.Forward;
-		right = ang.Right;
-		up = ang.Up;
 
 		var maxLen = SuspensionLength;
 
@@ -242,113 +222,95 @@ public partial class VeloXWheel : Component
 					.Cylinder( Width, Radius, pos, endPos )
 					.Rotated( vehicle.WorldTransform.Rotation * CylinderOffset )
 					.UseRenderMeshes( false )
-					.UseHitPosition( false )
+					.UseHitPosition( true )
 					.WithoutTags( vehicle.WheelIgnoredTags )
 					.Run();
 
+		forward = Vector3.VectorPlaneProject( ang.Forward, Trace.Normal );
+		right = Vector3.VectorPlaneProject( ang.Right, Trace.Normal );
+
 		var fraction = Trace.Fraction;
 
-		contactPos = pos - maxLen * fraction * up;
+		contactPos = pos - maxLen * fraction * ang.Up;
 
 		LocalPosition = vehicle.WorldTransform.PointToLocal( contactPos );
 
 		DoSuspensionSounds( vehicle, fraction - lastFraction );
 		lastFraction = fraction;
 
-		var normal = Trace.Normal;
-
-		var vel = vehicle.Body.GetVelocityAtPoint( pos );
-
-		vel.x = vel.x.InchToMeter();
-		vel.y = vel.y.InchToMeter();
-		vel.z = vel.z.InchToMeter();
-
 		if ( !IsOnGround )
-		{
-			SideSlip = 0;
-			ForwardSlip = 0;
 			return;
-		}
+
+		var vel = vehicle.Body.GetVelocityAtPoint( contactPos );
 
 		var offset = maxLen - (fraction * maxLen);
-		var springForce = (offset * SpringStrength);
+		var springForce = offset * SpringStrength;
 		var damperForce = (lastSpringOffset - offset) * SpringDamper;
+
 		lastSpringOffset = offset;
-		force = (springForce - damperForce) * MathF.Max( 0, up.Dot( normal ) ) * normal / dt;
-
-		// Vector3.CalculateVelocityOffset is broken (need fix)
-		//var velU = normal.Dot( vel ).MeterToInch();
-		//if ( velU < 0 && offset + Math.Abs( velU * dt ) > SuspensionLength )
-		//{
-		//	var (linearVel, angularVel) = vehicle.Body.PhysicsBody.CalculateVelocityOffset( (-velU.InchToMeter() / dt) * normal, pos );
-		//	vehicle.Body.Velocity += linearVel;
-		//	vehicle.Body.AngularVelocity += angularVel;
-		//}
 
 
-		load = springForce - damperForce;
+		var velU = Trace.Normal.Dot( vel );
-		load = Math.Max( load, 0 );
 
-		var longitudinalLoadCoefficient = GetLongitudinalLoadCoefficient( load );
+		if ( velU < 0 && offset + Math.Abs( velU * Time.Delta ) > SuspensionLength )
-		var lateralLoadCoefficient = GetLateralLoadCoefficient( load );
-
-		float forwardSpeed = 0;
-		float sideSpeed = 0;
-
-
-		if ( IsOnGround )
 		{
-			forwardSpeed = vel.Dot( forward );
+			vehicle.Body.CalculateVelocityOffset( -velU / Time.Delta * Trace.Normal, pos, out var linearImp, out var angularImp );
-			sideSpeed = vel.Dot( right );
+
+			vehicle.Body.Velocity += linearImp;
+			vehicle.Body.AngularVelocity += angularImp;
+			vehicle.Body.CalculateVelocityOffset( Trace.HitPosition - (contactPos + Trace.Normal * velU * Time.Delta), pos, out var lin, out _ );
+
+			vehicle.WorldPosition += lin / Time.Delta;
+			damperForce = 0;
+
 		}
 
-		(float W, float Sx, float Fx, float _) = StepLongitudinal(
+		force = (springForce - damperForce) * Trace.Normal;
-		   forwardSpeed,
+
-		   longitudinalLoadCoefficient,
+		load = Math.Max( springForce - damperForce, 0 );
-		   0.95f,
+		float R = Radius.InchToMeter();
-		   0.9f,
+
-		   dt
+		float forwardSpeed = vel.Dot( forward ).InchToMeter();
+		float sideSpeed = vel.Dot( right ).InchToMeter();
+
+		float longitudinalLoadCoefficient = GetLongitudinalLoadCoefficient( load );
+		float lateralLoadCoefficient = GetLateralLoadCoefficient( load );
+
+		float F_roll = TirePreset.GetRollingResistance( angularVelocity * R, 1.0f ) * 10000;
+	
+		( float W, float Sx, float Fx, float counterTq) = StepLongitudinal(
+			Torque,
+			Brake * BrakePowerMax + F_roll,
+			forwardSpeed,
+			angularVelocity,
+			longitudinalLoadCoefficient,
+			R,
+			Inertia
 		);
 
-		(float Sy, float Fy) = StepLateral(
+		StepLateral( forwardSpeed, sideSpeed, lateralLoadCoefficient, out float Sy, out float Fy );
-			forwardSpeed,
-			sideSpeed,
-			lateralLoadCoefficient,
-			0.95f,
-			0.9f,
-			dt
-		);
 
 		SlipCircle( Sx, Sy, Fx, ref Fy );
+
+		CounterTorque = counterTq;
 		angularVelocity = W;
 
-		forwardFriction = new Friction()
+		force += forward * Fx;
-		{
+		force += right * Fy * Math.Clamp( vehicle.TotalSpeed * 0.005f, 0, 1 );
-			Slip = Sx,
+		ForwardSlip = Sx;
-			Force = Fx.MeterToInch(),
+		SideSlip = Sy * Math.Clamp( vehicle.TotalSpeed * 0.005f, 0, 1 );
-			Speed = forwardSpeed
-		};
 
-		sideFriction = new Friction()
+		vehicle.Body.ApplyForceAt( pos, force / Time.Delta );
-		{
-			Slip = Sy,
-			Force = Fy.MeterToInch(),
-			Speed = sideSpeed
-		};
-
-
-		var frictionforce = right * sideFriction.Force + forward * forwardFriction.Force;
-
-		vehicle.Body.ApplyForceAt( contactPos, force + frictionforce );
 
 	}
 
-
+#if DEBUG
-	// debug
 	protected override void OnUpdate()
 	{
-		DebugOverlay.Normal( contactPos, forward * forwardFriction.Force / 10000f, Color.Red, overlay: true );
+		DebugOverlay.Normal( contactPos, forward * forwardFriction, Color.Red, overlay: true );
-		DebugOverlay.Normal( contactPos, right * sideFriction.Force / 10000f, Color.Green, overlay: true );
+		DebugOverlay.Normal( contactPos, right * sideFriction, Color.Green, overlay: true );
-		DebugOverlay.Normal( contactPos, up * force / 50000f, Color.Blue, overlay: true );
+		DebugOverlay.Normal( contactPos, up * force / 1000f, Color.Blue, overlay: true );
 	}
+#endif
+
 }

Code/Base/Wheel/WheelFriction.cs

@@ -1,12 +0,0 @@
-using Sandbox;
-
-namespace VeloX;
-
-
-[GameResource( "Wheel Friction", "whfric", "Wheel Friction", Category = "VeloX", Icon = "radio_button_checked" )]
-public class WheelFriction : GameResource
-{
-	public FrictionPreset Longitudinal { get; set; }
-	public FrictionPreset Lateral { get; set; }
-	public FrictionPreset Aligning { get; set; }
-}

Code/Car/VeloXCar.Engine.cs

@@ -1,354 +1,365 @@
 using Sandbox;
 using System;
 using System.Collections.Generic;
+using VeloX.Powertrain;
 
 namespace VeloX;
 
 public partial class VeloXCar
 {
-	[Property, Feature( "Engine" ), Sync] public EngineState EngineState { get; set; }
-	[Property, Feature( "Engine" )] public EngineStream Stream { get; set; }
-	public EngineStreamPlayer StreamPlayer { get; set; }
 
-	[Property, Feature( "Engine" )] public float MinRPM { get; set; } = 800;
+	[Property, Feature( "Engine" )] Engine Engine { get; set; }
-	[Property, Feature( "Engine" )] public float MaxRPM { get; set; } = 7000;
-	[Property, Feature( "Engine" ), Range( -1, 1 )]
-	public float PowerDistribution
-	{
-		get => powerDistribution; set
-		{
-			powerDistribution = value;
-			UpdatePowerDistribution();
-		}
-	}
-	[Property, Feature( "Engine" )] public float FlyWheelMass { get; set; } = 80f;
-	[Property, Feature( "Engine" )] public float FlyWheelRadius { get; set; } = 0.5f;
-	[Property, Feature( "Engine" )] public float FlywheelFriction { get; set; } = -6000;
-	[Property, Feature( "Engine" )] public float FlywheelTorque { get; set; } = 20000;
-	[Property, Feature( "Engine" )] public float EngineBrakeTorque { get; set; } = 2000;
-	[Property, Feature( "Engine" )]
-	public Dictionary<int, float> Gears { get; set; } = new()
-	{
-		[-1] = 2.5f,
-		[0] = 0f,
-		[1] = 2.8f,
-		[2] = 1.7f,
-		[3] = 1.2f,
-		[4] = 0.9f,
-		[5] = 0.75f,
-		[6] = 0.7f
-	};
-	[Property, Feature( "Engine" )] public float DifferentialRatio { get; set; } = 1f;
-	[Property, Feature( "Engine" ), Range( 0, 1 )] public float TransmissionEfficiency { get; set; } = 0.8f;
-	[Property, Feature( "Engine" )] private float MinRPMTorque { get; set; } = 5000f;
-	[Property, Feature( "Engine" )] private float MaxRPMTorque { get; set; } = 8000f;
-	[Sync] public int Gear { get; set; } = 0;
-	[Sync] public float Clutch { get; set; } = 1;
-	[Sync( SyncFlags.Interpolate )] public float EngineRPM { get; set; }
-	public float RPMPercent => (EngineRPM - MinRPM) / MaxRPM;
-
-	private const float TAU = MathF.Tau;
-
-	private int MinGear { get; set; }
-	private int MaxGear { get; set; }
-
-	[Sync] public bool IsRedlining { get; private set; }
-
-	private float flywheelVelocity;
-	private TimeUntil switchCD = 0;
-	private float groundedCount;
-	private float burnout;
-
-	private float frontBrake;
-	private float rearBrake;
-
-	private float availableFrontTorque;
-	private float availableRearTorque;
-
-	private float avgSideSlip;
-	private float avgPoweredRPM;
-	private float avgForwardSlip;
-
-	private float inputThrottle, inputBrake;
-	private bool inputHandbrake;
-	private float transmissionRPM;
-	private float powerDistribution;
-
-	public float FlywheelRPM
-	{
-		get => flywheelVelocity * 60 / TAU;
-		set
-		{
-			flywheelVelocity = value * TAU / 60; EngineRPM = value;
-		}
-	}
-	private void UpdateGearList()
-	{
-		int minGear = 0;
-		int maxGear = 0;
-
-		foreach ( var (gear, ratio) in Gears )
-		{
-
-			if ( gear < minGear )
-				minGear = gear;
-
-			if ( gear > maxGear )
-				maxGear = gear;
-
-			if ( minGear != 0 || maxGear != 0 )
-			{
-				SwitchGear( 0, false );
-			}
-		}
-
-		MinGear = minGear;
-		MaxGear = maxGear;
-
-	}
-
-
-	public void SwitchGear( int index, bool cooldown = true )
-	{
-		if ( Gear == index ) return;
-		index = Math.Clamp( index, MinGear, MaxGear );
-
-		if ( index == 0 || !cooldown )
-			switchCD = 0;
-		else
-			switchCD = 0.3f;
-		Clutch = 1;
-		Gear = index;
-	}
-
-	public float TransmissionToEngineRPM( int gear ) => avgPoweredRPM * Gears[gear] * DifferentialRatio * 60 / TAU;
-	public float GetTransmissionMaxRPM( int gear ) => FlywheelRPM / Gears[gear] / DifferentialRatio;
-
-	private void UpdatePowerDistribution()
-	{
-		if ( Wheels is null ) return;
-		int frontCount = 0, rearCount = 0;
-
-		foreach ( var wheel in Wheels )
-		{
-			if ( wheel.IsFront )
-				frontCount++;
-			else
-				rearCount++;
-
-		}
-
-		float frontDistribution = 0.5f + PowerDistribution * 0.5f;
-
-		float rearDistribution = 1 - frontDistribution;
-
-		frontDistribution /= frontCount;
-		rearDistribution /= rearCount;
-
-		foreach ( var wheel in Wheels )
-			if ( wheel.IsFront )
-				wheel.DistributionFactor = frontDistribution;
-			else
-				wheel.DistributionFactor = rearDistribution;
-	}
-
-	private void EngineAccelerate( float torque, float dt )
-	{
-		var inertia = 0.5f * FlyWheelMass * FlyWheelRadius * FlyWheelRadius;
-		var angularAcceleration = torque / inertia;
-
-		flywheelVelocity += angularAcceleration * dt;
-	}
-
-	private float GetTransmissionTorque( int gear, float minTorque, float maxTorque )
-	{
-		var torque = FlywheelRPM.Remap( MinRPM, MaxRPM, minTorque, maxTorque, true );
-		torque *= (1 - Clutch);
-		torque = torque * Gears[gear] * DifferentialRatio * TransmissionEfficiency;
-
-		return gear == -1 ? -torque : torque;
-	}
-
-	private void AutoGearSwitch()
-	{
-		if ( ForwardSpeed < 100 && Input.Down( "Backward" ) )
-		{
-			SwitchGear( -1, false );
-			return;
-		}
-
-		var currentGear = Gear;
-
-		if ( currentGear < 0 && ForwardSpeed < -100 )
-			return;
-
-		if ( Math.Abs( avgForwardSlip ) > 10 )
-			return;
-
-		var gear = Math.Clamp( currentGear, 1, MaxGear );
-
-		float minRPM = MinRPM, maxRPM = MaxRPM;
-
-
-		maxRPM *= 0.98f;
-
-		float gearRPM;
-
-
-		for ( int i = 1; i <= MaxGear; i++ )
-		{
-			gearRPM = TransmissionToEngineRPM( i );
-
-			if ( (i == 1 && gearRPM < minRPM) || (gearRPM > minRPM && gearRPM < maxRPM) )
-			{
-				gear = i;
-				break;
-			}
-		}
-
-		var threshold = minRPM + (maxRPM - minRPM) * (0.5 - Throttle * 0.3);
-		if ( gear < currentGear && gear > currentGear - 2 && EngineRPM > threshold )
-			return;
-
-		SwitchGear( gear );
-	}
-
-	private float EngineClutch( float dt )
-	{
-		if ( !switchCD )
-		{
-			inputThrottle = 0;
-
-			return 0;
-		}
-
-		if ( inputHandbrake )
-			return 1;
-
-		var absForwardSpeed = Math.Abs( ForwardSpeed );
-
-		if ( groundedCount < 1 && absForwardSpeed > 30 )
-			return 1;
-
-		if ( ForwardSpeed < -50 && inputBrake > 0 && Gear < 0 )
-			return 1;
-
-		if ( absForwardSpeed > 200 )
-			return 0;
-
-		return inputThrottle > 0.1f ? 0 : 1;
-	}
 
 	private void EngineThink( float dt )
 	{
-		inputThrottle = Input.Down( "Forward" ) ? 1 : 0;
+		Engine.Throttle = Input.Down( "Forward" ) ? 1 : 0;
-		inputBrake = Input.Down( "Backward" ) ? 1 : 0;
+		Engine.ForwardStep( 0, 0 );
-		inputHandbrake = Input.Down( "Jump" );
-		if ( burnout > 0 )
-		{
-			SwitchGear( 1, false );
-			if ( inputThrottle < 0.1f || inputBrake < 0.1f )
-				burnout = 0;
-		}
-		else
-			AutoGearSwitch();
-
-		if ( Gear < 0 )
-			(inputBrake, inputThrottle) = (inputThrottle, inputBrake);
-
-		var rpm = FlywheelRPM;
-
-		var clutch = EngineClutch( dt );
-
-		if ( inputThrottle > 0.1 && inputBrake > 0.1 && Math.Abs( ForwardSpeed ) < 50 )
-		{
-			burnout = MathX.Approach( burnout, 1, dt * 2 );
-			Clutch = 0;
-
-		}
-		else if ( inputHandbrake )
-		{
-			frontBrake = 0f;
-			rearBrake = 0.5f;
-			Clutch = 1;
-			clutch = 1;
-		}
-		else
-		{
-			if ( (Gear == -1 || Gear == 1) && inputThrottle < 0.05f && inputBrake < 0.1f && groundedCount > 1 && rpm < MinRPM * 1.2f )
-				inputBrake = 0.2f;
-
-			frontBrake = inputBrake * 0.5f;
-			rearBrake = inputBrake * 0.5f;
-		}
-
-		clutch = MathX.Approach( Clutch, clutch, dt * ((Gear < 2 && inputThrottle > 0.1f) ? 6 : 2) );
-
-		Clutch = clutch;
-
-		var isRedlining = false;
-		transmissionRPM = 0;
-
-		if ( Gear != 0 )
-		{
-			transmissionRPM = TransmissionToEngineRPM( Gear );
-			transmissionRPM = Gear < 0 ? -transmissionRPM : transmissionRPM;
-			rpm = (rpm * clutch) + (MathF.Max( 0, transmissionRPM ) * (1 - clutch));
-		}
-		var throttle = Throttle;
-
-		var gearTorque = GetTransmissionTorque( Gear, MinRPMTorque, MaxRPMTorque );
-
-		var availableTorque = gearTorque * throttle;
-
-		if ( transmissionRPM < 0 )
-		{
-			availableTorque += gearTorque * 2;
-		}
-		else
-		{
-			var engineBrakeTorque = GetTransmissionTorque( Gear, EngineBrakeTorque, EngineBrakeTorque );
-
-			availableTorque -= engineBrakeTorque * (1 - throttle) * 0.5f;
-		}
-
-		var maxRPM = MaxRPM;
-
-		if ( rpm < MinRPM )
-		{
-			rpm = MinRPM;
-		}
-		else if ( rpm > maxRPM )
-		{
-
-			if ( rpm > maxRPM * 1.2f )
-				availableTorque = 0;
-
-			rpm = maxRPM;
-
-			if ( Gear != MaxGear || groundedCount < Wheels.Count )
-				isRedlining = true;
-		}
-
-		FlywheelRPM = Math.Clamp( rpm, 0, maxRPM );
-
-		if ( burnout > 0 )
-			availableTorque += availableTorque * burnout * 0.1f;
-
-		var front = 0.5f + PowerDistribution * 0.5f;
-		var rear = 1 - front;
-
-		availableFrontTorque = availableTorque * front;
-		availableRearTorque = availableTorque * rear;
-
-		throttle = MathX.Approach( throttle, inputThrottle, dt * 4 );
-
-
-		EngineAccelerate( FlywheelFriction + FlywheelTorque * throttle, dt );
-
-		Throttle = throttle;
-
-		IsRedlining = (isRedlining && inputThrottle > 0);
 	}
 
+
+	//[Property, Feature( "Engine" ), Sync] public EngineState EngineState { get; set; }
+	//[Property, Feature( "Engine" )] public EngineStream Stream { get; set; }
+	//public EngineStreamPlayer StreamPlayer { get; set; }
+
+	//[Property, Feature( "Engine" )] public float MinRPM { get; set; } = 800;
+	//[Property, Feature( "Engine" )] public float MaxRPM { get; set; } = 7000;
+	//[Property, Feature( "Engine" ), Range( -1, 1 )]
+	//public float PowerDistribution
+	//{
+	//	get => powerDistribution; set
+	//	{
+	//		powerDistribution = value;
+	//		UpdatePowerDistribution();
+	//	}
+	//}
+	//[Property, Feature( "Engine" )] public float FlyWheelMass { get; set; } = 80f;
+	//[Property, Feature( "Engine" )] public float FlyWheelRadius { get; set; } = 0.5f;
+	//[Property, Feature( "Engine" )] public float FlywheelFriction { get; set; } = -6000;
+	//[Property, Feature( "Engine" )] public float FlywheelTorque { get; set; } = 20000;
+	//[Property, Feature( "Engine" )] public float EngineBrakeTorque { get; set; } = 2000;
+	//[Property, Feature( "Engine" )]
+	//public Dictionary<int, float> Gears { get; set; } = new()
+	//{
+	//	[-1] = 2.5f,
+	//	[0] = 0f,
+	//	[1] = 2.8f,
+	//	[2] = 1.7f,
+	//	[3] = 1.2f,
+	//	[4] = 0.9f,
+	//	[5] = 0.75f,
+	//	[6] = 0.7f
+	//};
+	//[Property, Feature( "Engine" )] public float DifferentialRatio { get; set; } = 1f;
+	//[Property, Feature( "Engine" ), Range( 0, 1 )] public float TransmissionEfficiency { get; set; } = 0.8f;
+	//[Property, Feature( "Engine" )] private float MinRPMTorque { get; set; } = 5000f;
+	//[Property, Feature( "Engine" )] private float MaxRPMTorque { get; set; } = 8000f;
+	//[Sync] public int Gear { get; set; } = 0;
+	//[Sync] public float Clutch { get; set; } = 1;
+	//[Sync( SyncFlags.Interpolate )] public float EngineRPM { get; set; }
+	//public float RPMPercent => (EngineRPM - MinRPM) / MaxRPM;
+
+	//private const float TAU = MathF.Tau;
+
+	//private int MinGear { get; set; }
+	//private int MaxGear { get; set; }
+
+	//[Sync] public bool IsRedlining { get; private set; }
+
+	//private float flywheelVelocity;
+	//private TimeUntil switchCD = 0;
+	//private float groundedCount;
+	//private float burnout;
+
+	//private float frontBrake;
+	//private float rearBrake;
+
+	//private float availableFrontTorque;
+	//private float availableRearTorque;
+
+	//private float avgSideSlip;
+	//private float avgPoweredRPM;
+	//private float avgForwardSlip;
+
+	//private float inputThrottle, inputBrake;
+	//private bool inputHandbrake;
+	//private float transmissionRPM;
+	//private float powerDistribution;
+
+	//public float FlywheelRPM
+	//{
+	//	get => flywheelVelocity * 60 / TAU;
+	//	set
+	//	{
+	//		flywheelVelocity = value * TAU / 60; EngineRPM = value;
+	//	}
+	//}
+	//private void UpdateGearList()
+	//{
+	//	int minGear = 0;
+	//	int maxGear = 0;
+
+	//	foreach ( var (gear, ratio) in Gears )
+	//	{
+
+	//		if ( gear < minGear )
+	//			minGear = gear;
+
+	//		if ( gear > maxGear )
+	//			maxGear = gear;
+
+	//		if ( minGear != 0 || maxGear != 0 )
+	//		{
+	//			SwitchGear( 0, false );
+	//		}
+	//	}
+
+	//	MinGear = minGear;
+	//	MaxGear = maxGear;
+
+	//}
+
+
+	//public void SwitchGear( int index, bool cooldown = true )
+	//{
+	//	if ( Gear == index ) return;
+	//	index = Math.Clamp( index, MinGear, MaxGear );
+
+	//	if ( index == 0 || !cooldown )
+	//		switchCD = 0;
+	//	else
+	//		switchCD = 0.3f;
+	//	Clutch = 1;
+	//	Gear = index;
+	//}
+
+	//public float TransmissionToEngineRPM( int gear ) => avgPoweredRPM * Gears[gear] * DifferentialRatio * 60 / TAU;
+	//public float GetTransmissionMaxRPM( int gear ) => FlywheelRPM / Gears[gear] / DifferentialRatio;
+
+	//private void UpdatePowerDistribution()
+	//{
+	//	if ( Wheels is null ) return;
+	//	int frontCount = 0, rearCount = 0;
+
+	//	foreach ( var wheel in Wheels )
+	//	{
+	//		if ( wheel.IsFront )
+	//			frontCount++;
+	//		else
+	//			rearCount++;
+
+	//	}
+
+	//	float frontDistribution = 0.5f + PowerDistribution * 0.5f;
+
+	//	float rearDistribution = 1 - frontDistribution;
+
+	//	frontDistribution /= frontCount;
+	//	rearDistribution /= rearCount;
+
+	//	foreach ( var wheel in Wheels )
+	//		if ( wheel.IsFront )
+	//			wheel.DistributionFactor = frontDistribution;
+	//		else
+	//			wheel.DistributionFactor = rearDistribution;
+	//}
+
+	//private void EngineAccelerate( float torque, float dt )
+	//{
+	//	var inertia = 0.5f * FlyWheelMass * FlyWheelRadius * FlyWheelRadius;
+	//	var angularAcceleration = torque / inertia;
+
+	//	flywheelVelocity += angularAcceleration * dt;
+	//}
+
+	//private float GetTransmissionTorque( int gear, float minTorque, float maxTorque )
+	//{
+	//	var torque = FlywheelRPM.Remap( MinRPM, MaxRPM, minTorque, maxTorque, true );
+	//	torque *= (1 - Clutch);
+	//	torque = torque * Gears[gear] * DifferentialRatio * TransmissionEfficiency;
+
+	//	return gear == -1 ? -torque : torque;
+	//}
+
+	//private void AutoGearSwitch()
+	//{
+	//	if ( ForwardSpeed < 100 && Input.Down( "Backward" ) )
+	//	{
+	//		SwitchGear( -1, false );
+	//		return;
+	//	}
+
+	//	var currentGear = Gear;
+
+	//	if ( currentGear < 0 && ForwardSpeed < -100 )
+	//		return;
+
+	//	if ( Math.Abs( avgForwardSlip ) > 10 )
+	//		return;
+
+	//	var gear = Math.Clamp( currentGear, 1, MaxGear );
+
+	//	float minRPM = MinRPM, maxRPM = MaxRPM;
+
+
+	//	maxRPM *= 0.98f;
+
+	//	float gearRPM;
+
+
+	//	for ( int i = 1; i <= MaxGear; i++ )
+	//	{
+	//		gearRPM = TransmissionToEngineRPM( i );
+
+	//		if ( (i == 1 && gearRPM < minRPM) || (gearRPM > minRPM && gearRPM < maxRPM) )
+	//		{
+	//			gear = i;
+	//			break;
+	//		}
+	//	}
+
+	//	var threshold = minRPM + (maxRPM - minRPM) * (0.5 - Throttle * 0.3);
+	//	if ( gear < currentGear && gear > currentGear - 2 && EngineRPM > threshold )
+	//		return;
+
+	//	SwitchGear( gear );
+	//}
+
+	//private float EngineClutch( float dt )
+	//{
+	//	if ( !switchCD )
+	//	{
+	//		inputThrottle = 0;
+
+	//		return 0;
+	//	}
+
+	//	if ( inputHandbrake )
+	//		return 1;
+
+	//	var absForwardSpeed = Math.Abs( ForwardSpeed );
+
+	//	if ( groundedCount < 1 && absForwardSpeed > 30 )
+	//		return 1;
+
+	//	if ( ForwardSpeed < -50 && inputBrake > 0 && Gear < 0 )
+	//		return 1;
+
+	//	if ( absForwardSpeed > 200 )
+	//		return 0;
+
+	//	return inputThrottle > 0.1f ? 0 : 1;
+	//}
+
+	//private void EngineThink( float dt )
+	//{
+	//	inputThrottle = Input.Down( "Forward" ) ? 1 : 0;
+	//	inputBrake = Input.Down( "Backward" ) ? 1 : 0;
+	//	inputHandbrake = Input.Down( "Jump" );
+	//	if ( burnout > 0 )
+	//	{
+	//		SwitchGear( 1, false );
+	//		if ( inputThrottle < 0.1f || inputBrake < 0.1f )
+	//			burnout = 0;
+	//	}
+	//	else
+	//		AutoGearSwitch();
+
+	//	if ( Gear < 0 )
+	//		(inputBrake, inputThrottle) = (inputThrottle, inputBrake);
+
+	//	var rpm = FlywheelRPM;
+
+	//	var clutch = EngineClutch( dt );
+
+	//	if ( inputThrottle > 0.1 && inputBrake > 0.1 && Math.Abs( ForwardSpeed ) < 50 )
+	//	{
+	//		burnout = MathX.Approach( burnout, 1, dt * 2 );
+	//		Clutch = 0;
+
+	//	}
+	//	else if ( inputHandbrake )
+	//	{
+	//		frontBrake = 0f;
+	//		rearBrake = 0.5f;
+	//		Clutch = 1;
+	//		clutch = 1;
+	//	}
+	//	else
+	//	{
+	//		if ( (Gear == -1 || Gear == 1) && inputThrottle < 0.05f && inputBrake < 0.1f && groundedCount > 1 && rpm < MinRPM * 1.2f )
+	//			inputBrake = 0.2f;
+
+	//		frontBrake = inputBrake * 0.5f;
+	//		rearBrake = inputBrake * 0.5f;
+	//	}
+
+	//	clutch = MathX.Approach( Clutch, clutch, dt * ((Gear < 2 && inputThrottle > 0.1f) ? 6 : 2) );
+
+	//	Clutch = clutch;
+
+	//	var isRedlining = false;
+	//	transmissionRPM = 0;
+
+	//	if ( Gear != 0 )
+	//	{
+	//		transmissionRPM = TransmissionToEngineRPM( Gear );
+	//		transmissionRPM = Gear < 0 ? -transmissionRPM : transmissionRPM;
+	//		rpm = (rpm * clutch) + (MathF.Max( 0, transmissionRPM ) * (1 - clutch));
+	//	}
+	//	var throttle = Throttle;
+
+	//	var gearTorque = GetTransmissionTorque( Gear, MinRPMTorque, MaxRPMTorque );
+
+	//	var availableTorque = gearTorque * throttle;
+
+	//	if ( transmissionRPM < 0 )
+	//	{
+	//		availableTorque += gearTorque * 2;
+	//	}
+	//	else
+	//	{
+	//		var engineBrakeTorque = GetTransmissionTorque( Gear, EngineBrakeTorque, EngineBrakeTorque );
+
+	//		availableTorque -= engineBrakeTorque * (1 - throttle) * 0.5f;
+	//	}
+
+	//	var maxRPM = MaxRPM;
+
+	//	if ( rpm < MinRPM )
+	//	{
+	//		rpm = MinRPM;
+	//	}
+	//	else if ( rpm > maxRPM )
+	//	{
+
+	//		if ( rpm > maxRPM * 1.2f )
+	//			availableTorque = 0;
+
+	//		rpm = maxRPM;
+
+	//		if ( Gear != MaxGear || groundedCount < Wheels.Count )
+	//			isRedlining = true;
+	//	}
+
+	//	FlywheelRPM = Math.Clamp( rpm, 0, maxRPM );
+
+	//	if ( burnout > 0 )
+	//		availableTorque += availableTorque * burnout * 0.1f;
+
+	//	var front = 0.5f + PowerDistribution * 0.5f;
+	//	var rear = 1 - front;
+
+	//	availableFrontTorque = availableTorque * front;
+	//	availableRearTorque = availableTorque * rear;
+
+	//	throttle = MathX.Approach( throttle, inputThrottle, dt * 4 );
+
+
+	//	EngineAccelerate( FlywheelFriction + FlywheelTorque * throttle, dt );
+
+	//	Throttle = throttle;
+
+	//	IsRedlining = (isRedlining && inputThrottle > 0);
+	//}
+
 }

Code/Car/VeloXCar.Steering.cs

@@ -14,33 +14,40 @@ public partial class VeloXCar
 	[Property, Feature( "Steer" )] public float MaxSteerAngle { get; set; } = 35f;
 
 	[Sync] public float Steering { get; private set; }
-	private float jTurnMultiplier;
 
 	private float inputSteer;
+
+	public static float SignedAngle( Vector3 from, Vector3 to, Vector3 axis )
+	{
+		float unsignedAngle = Vector3.GetAngle( from, to );
+
+		float cross_x = from.y * to.z - from.z * to.y;
+		float cross_y = from.z * to.x - from.x * to.z;
+		float cross_z = from.x * to.y - from.y * to.x;
+		float sign = MathF.Sign( axis.x * cross_x + axis.y * cross_y + axis.z * cross_z );
+		return unsignedAngle * sign;
+	}
+	public float VelocityAngle { get; private set; }
+	public int CarDirection { get { return ForwardSpeed.InchToMeter() < 5 ? 0 : (VelocityAngle < 90 && VelocityAngle > -90 ? 1 : -1); } }
 	private void UpdateSteering( float dt )
 	{
 		var inputSteer = Input.AnalogMove.y;
-		var absInputSteer = Math.Abs( inputSteer );
 
-		var sideSlip = Math.Clamp( avgSideSlip, -1, 1 );
 
-		var steerConeFactor = Math.Clamp( TotalSpeed / SteerConeMaxSpeed, 0, 1 );
+		VelocityAngle = 0;// -SignedAngle( Body.Velocity, WorldRotation.Forward, WorldRotation.Up );
-		var steerCone = 1 - steerConeFactor * (1 - SteerConeMaxAngle);
 
-		steerCone = Math.Clamp( steerCone, Math.Abs( sideSlip ), 1 );
+		//var steerConeFactor = Math.Clamp( TotalSpeed / SteerConeMaxSpeed, 0, 1 );
+		//var steerCone = 1 - steerConeFactor * (1 - SteerConeMaxAngle);
 
-		inputSteer = ExpDecay( this.inputSteer, inputSteer * steerCone, SteerConeChangeRate, dt );
+		inputSteer = ExpDecay( this.inputSteer, inputSteer, SteerConeChangeRate, dt );
 		this.inputSteer = inputSteer;
-		var counterSteer = sideSlip * steerConeFactor * (1 - absInputSteer);
-		counterSteer = Math.Clamp( counterSteer, -1, 1 ) * CounterSteer;
 
-		inputSteer = Math.Clamp( inputSteer + counterSteer, -1, 1 );
+		float target = -inputSteer * MaxSteerAngle;
+		if ( CarDirection > 0 )
+			target -= VelocityAngle * CounterSteer;
+
+		inputSteer = Math.Clamp( inputSteer, -1, 1 );
 		Steering = inputSteer;
-		SteerAngle = new( 0, inputSteer * MaxSteerAngle, 0 );
+		SteerAngle = new( 0, target, 0 );
-
-		if ( ForwardSpeed < -100 )
-			jTurnMultiplier = 0.5f;
-		else
-			jTurnMultiplier = ExpDecay( jTurnMultiplier, 1, 2, dt );
 	}
 }

Code/Car/VeloXCar.Wheel.cs

@@ -2,45 +2,9 @@
 
 public partial class VeloXCar
 {
-
 	private void WheelThink( in float dt )
 	{
-		var maxRPM = GetTransmissionMaxRPM( Gear );
-
-
-		var frontTorque = availableFrontTorque;
-		var rearTorque = availableRearTorque;
-
-
-		groundedCount = 0;
-		float avgRPM = 0, totalSideSlip = 0, totalForwardSlip = 0;
-
 		foreach ( var w in Wheels )
-		{
 			w.Update( this, dt );
-
-			totalSideSlip += w.SideSlip;
-			totalForwardSlip += w.ForwardSlip;
-			var rpm = w.RPM;
-
-			avgRPM += rpm * w.DistributionFactor;
-
-			w.Torque = w.DistributionFactor * (w.IsFront ? frontTorque : rearTorque);
-			w.Brake = w.IsFront ? frontBrake : rearBrake;
-
-			if ( inputHandbrake && !w.IsFront )
-				w.RPM = 0;
-
-			if ( rpm > maxRPM )
-				w.RPM = maxRPM;
-
-			if ( w.IsOnGround )
-				groundedCount++;
-
-		}
-		avgPoweredRPM = avgRPM;
-		avgSideSlip = totalSideSlip / Wheels.Count;
-		avgForwardSlip = totalForwardSlip / Wheels.Count;
-
 	}
 }

Code/Car/VeloXCar.cs

@@ -7,32 +7,6 @@ namespace VeloX;
 [Title( "VeloX - Car" )]
 public partial class VeloXCar : VeloXBase
 {
-	protected override void OnStart()
-	{
-		base.OnStart();
-		StreamPlayer = new( Stream );
-		if ( IsDriver )
-		{
-			UpdateGearList();
-			UpdatePowerDistribution();
-		}
-	}
-
-	protected override void OnUpdate()
-	{
-		base.OnUpdate();
-		if ( StreamPlayer is not null )
-		{
-
-			StreamPlayer.Throttle = Throttle;
-			StreamPlayer.RPMPercent = RPMPercent;
-			StreamPlayer.EngineState = EngineState;
-			StreamPlayer.IsRedlining = IsRedlining;
-
-			StreamPlayer.Update( Time.Delta, WorldPosition );
-		}
-
-	}
 	protected override void OnFixedUpdate()
 	{
 		if ( !IsDriver )
@@ -40,9 +14,10 @@ public partial class VeloXCar : VeloXBase
 
 		base.OnFixedUpdate();
 
-		Brake = Math.Clamp( frontBrake + rearBrake + (Input.Down( "Jump" ) ? 1 : 0), 0, 1 );
+		Brake = Math.Clamp( (Input.Down( "Jump" ) ? 1 : 0), 0, 1 );
 
 		var dt = Time.Delta;
+
 		EngineThink( dt );
 		WheelThink( dt );
 		UpdateSteering( dt );

Code/Utils/PhysicsExtensions.cs

@@ -28,44 +28,38 @@ public static class PhysicsExtensions
 			value.x * (xz2 - wy2) + value.y * (yz2 + wx2) + value.z * (1.0f - xx2 - yy2)
 		);
 	}
+
 	/// <summary>
-	/// Calculates the linear and angular velocities on the center of mass for an offset impulse.
+	/// Calculates the linear and angular velocities on the object's center of mass for an offset impulse.
 	/// </summary>
 	/// <param name="physObj">The physics object</param>
 	/// <param name="impulse">The impulse acting on the object in kg*units/s (World frame)</param>
 	/// <param name="position">The location of the impulse in world coordinates</param>
-	/// <returns>
+	/// <param name="LinearVelocity">Linear velocity on center of mass (World frame)</param>
-	/// Vector1: Linear velocity from the impulse (World frame)
+	/// <param name="AngularVelocity">Angular velocity on center of mass (World frame)</param>
-	/// Vector2: Angular velocity from the impulse (Local frame)
+	public static void CalculateVelocityOffset(
-	/// </returns>
+		this Rigidbody physObj,
-	public static (Vector3 LinearVelocity, Vector3 AngularVelocity) CalculateVelocityOffset( this PhysicsBody physObj, Vector3 impulse, Vector3 position )
+		Vector3 impulse,
+		Vector3 position,
+		out Vector3 LinearVelocity,
+		out Vector3 AngularVelocity )
 	{
 		if ( !physObj.IsValid() || !physObj.MotionEnabled )
-			return (Vector3.Zero, Vector3.Zero);
+		{
+			LinearVelocity = 0;
+			AngularVelocity = 0;
+			return;
+		}
 
+		Vector3 com = physObj.WorldTransform.PointToWorld( physObj.MassCenter );
+		Rotation bodyRot = physObj.PhysicsBody.Rotation;
 
-		Vector3 linearVelocity = impulse / physObj.Mass;
+		Vector3 r = position - com;
-
+		Vector3 torque = Vector3.Cross( r, impulse );
-		Vector3 r = position - physObj.MassCenter;
+		Vector3 torqueLocal = bodyRot.Inverse * torque;
-
+		Vector3 angularVelocityLocal = torqueLocal * physObj.PhysicsBody.Inertia.Inverse;
-
+		AngularVelocity = bodyRot * angularVelocityLocal;
-		// Calculate torque impulse in world frame: τ = r × impulse
+		LinearVelocity = impulse * (1 / physObj.Mass);
-		Vector3 torqueImpulseWorld = r.Cross( impulse );
-		Rotation worldToLocal = physObj.Rotation.Inverse;
-		Vector3 torqueImpulseLocal = torqueImpulseWorld.Transform( worldToLocal );
-
-		var InverseInertiaDiagLocal = physObj.Inertia.Inverse;
-
-		// Compute angular velocity change in rad/s (local frame)
-		Vector3 angularVelocityRadLocal = new(
-			InverseInertiaDiagLocal.x * torqueImpulseLocal.x,
-			InverseInertiaDiagLocal.y * torqueImpulseLocal.y,
-			InverseInertiaDiagLocal.z * torqueImpulseLocal.z
-		);
-		const float radToDeg = 180f / MathF.PI;
-		Vector3 angularVelocityDegLocal = angularVelocityRadLocal * radToDeg;
-
-		return (linearVelocity, angularVelocityDegLocal);
 	}
 
 	/// <summary>
@@ -74,34 +68,31 @@ public static class PhysicsExtensions
 	/// <param name="physObj">The physics object</param>
 	/// <param name="impulse">The impulse acting on the object in kg*units/s (World frame)</param>
 	/// <param name="position">The location of the impulse in world coordinates</param>
-	/// <returns>
+	/// <param name="LinearImpulse">Linear impulse on center of mass (World frame)</param>
-	/// Vector1: Linear impulse on center of mass (World frame)
+	/// <param name="AngularImpulse">Angular impulse on center of mass (World frame)</param>
-	/// Vector2: Angular impulse on center of mass (Local frame)
+	public static void CalculateForceOffset(
-	/// </returns>
+		this Rigidbody physObj,
-	public static (Vector3 LinearImpulse, Vector3 AngularImpulse) CalculateForceOffset(
-		this PhysicsBody physObj,
 		Vector3 impulse,
-		Vector3 position )
+		Vector3 position,
+		out Vector3 LinearImpulse,
+		out Vector3 AngularImpulse )
 	{
 		if ( !physObj.IsValid() || !physObj.MotionEnabled )
 		{
-			return (Vector3.Zero, Vector3.Zero);
+			LinearImpulse = 0;
+			AngularImpulse = 0;
+			return;
 		}
 
-		// 1. Linear impulse is the same as the input impulse (conservation of momentum)
+		Vector3 com = physObj.WorldTransform.PointToWorld( physObj.MassCenter );
-		Vector3 linearImpulse = impulse;
+		Rotation bodyRot = physObj.PhysicsBody.Rotation;
 
-		// 2. Calculate angular impulse (torque) from the offset force
+		Vector3 r = position - com;
-		// τ = r * F (cross product of position relative to COM and force)
+		Vector3 torque = Vector3.Cross( r, impulse );
-		Vector3 centerOfMass = physObj.MassCenter;
+		Vector3 torqueLocal = bodyRot.Inverse * torque;
-		Vector3 relativePosition = position - centerOfMass;
+		Vector3 angularImpulseLocal = torqueLocal * physObj.PhysicsBody.Inertia.Inverse;
-		Vector3 worldAngularImpulse = relativePosition.Cross( impulse );
+		AngularImpulse = bodyRot * angularImpulseLocal;
-
+		LinearImpulse = impulse;
-		// Convert angular impulse to local space (since we'll use it with LocalInertia)
-		Rotation bodyRotation = physObj.Transform.Rotation;
-		Vector3 localAngularImpulse = bodyRotation.Inverse * worldAngularImpulse;
-
-		return (linearImpulse, localAngularImpulse);
 	}
 
 }

Editor/EngineStreamInspector.cs

@@ -1,55 +0,0 @@
-//using Editor;
-//using Editor.Assets;
-//using Sandbox;
-//using VeloX;
-//using static Editor.Inspectors.AssetInspector;
-
-//[CanEdit( "asset:engstr" )]
-//public class EngineStreamInspector : Widget, IAssetInspector
-//{
-//	EngineStream EngineStream;
-//	ControlSheet MainSheet;
-
-//	public EngineStreamInspector( Widget parent ) : base( parent )
-//	{
-//		Layout = Layout.Column();
-//		Layout.Margin = 12;
-//		Layout.Spacing = 12;
-
-//		MainSheet = new ControlSheet();
-
-//		Layout.Add( MainSheet, 1 );
-
-//	}
-
-//	[EditorEvent.Hotload]
-//	void RebuildSheet()
-//	{
-//		if ( EngineStream is null || MainSheet is null )
-//			return;
-
-//		Layout.Clear( true );
-//		var text = Layout.Add( new Editor.TextEdit() );
-//		var but = Layout.Add( new Editor.Button( "Load JSON" ) );
-//		but.Clicked += () =>
-//			{
-//				EngineStream.LoadFromJson( text.PlainText );
-//			};
-
-//		var so = EngineStream.GetSerialized();
-
-
-//		so.OnPropertyChanged += _ =>
-//			{
-//				EngineStream.StateHasChanged();
-//			};
-//		Layout.Add( ControlWidget.Create( so.GetProperty( nameof( EngineStream.Layers ) ) ) );
-//		Layout.Add( ControlWidget.Create( so.GetProperty( nameof( EngineStream.Parameters ) ) ) );
-//	}
-
-//	public void SetAsset( Asset asset )
-//	{
-//		EngineStream = asset.LoadResource<EngineStream>();
-//		RebuildSheet();
-//	}
-//}

Editor/Wheel/PacejkaWidget.cs

@@ -0,0 +1,48 @@
+using Editor;
+using Sandbox;
+
+namespace VeloX;
+
+[CustomEditor( typeof( Pacejka ) )]
+public class PacejkaWidget : ControlObjectWidget
+{
+	public override bool SupportsMultiEdit => false;
+	public override bool IncludeLabel => false;
+
+	[CustomEditor( typeof( Pacejka.PacejkaPreset ) )]
+	private class LateralForceWidget : ControlObjectWidget
+	{
+		public LateralForceWidget( SerializedProperty property ) : base( property, true )
+		{
+			Layout = Layout.Column();
+			Layout.Margin = 8f;
+			Layout.Spacing = 8;
+			foreach ( var item in TypeLibrary.GetType<Pacejka.PacejkaPreset>().Properties )
+			{
+				var row = Layout.AddRow();
+				row.Spacing = 8;
+				var propetry = SerializedObject.GetProperty( item.Name );
+				row.Add( new Label( propetry.Name ) );
+				row.Add( Create( propetry ) );
+			}
+		}
+	}
+	private Pacejka Pacejka;
+	public PacejkaWidget( SerializedProperty property ) : base( property, true )
+	{
+
+		var obj = SerializedObject;
+		Pacejka = obj.ParentProperty.GetValue<Pacejka>();
+
+		Layout = Layout.Column();
+		Layout.Margin = 8f;
+		Layout.Add( new Label.Body( $" {ToolTip}" ) { Color = Color.White } );
+		var tabs = Layout.Add( new TabWidget( null ) );
+		tabs.AddPage( nameof( Pacejka.Lateral ), null,
+			Layout.Add( Create( obj.GetProperty( nameof( Pacejka.Lateral ) ) ) )
+		);
+		tabs.AddPage( nameof( Pacejka.Longitudinal ), null,
+			Layout.Add( Create( obj.GetProperty( nameof( Pacejka.Longitudinal ) ) ) )
+		);
+	}
+}

Editor/Wheel/TirePresetPreview.cs

@@ -0,0 +1,149 @@
+using Editor;
+using Editor.Assets;
+using Editor.Inspectors;
+using Sandbox;
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace VeloX;
+
+[AssetPreview( "tire" )]
+class TirePresetPreview : AssetPreview
+{
+	private Texture texture;
+	public override bool IsAnimatedPreview => false;
+	[Range( 0.01f, 1 )] private float Zoom { get; set; } = 1;
+	private TirePreset Tire;
+	public AssetPreviewWidget Widget { get; private set; }
+	public override Widget CreateWidget( Widget parent )
+	{
+		Widget = parent as AssetPreviewWidget;
+
+		return null;
+	}
+	public override Widget CreateToolbar()
+	{
+		var info = new IconButton( "settings" );
+		info.Layout = Layout.Row();
+		info.MinimumSize = 16;
+		info.MouseLeftPress = () => OpenSettings( info );
+		return info;
+	}
+	public void OpenSettings( Widget parent )
+	{
+		var popup = new PopupWidget( parent )
+		{
+			IsPopup = true,
+			Layout = Layout.Column()
+		};
+
+		popup.Layout.Margin = 16;
+
+		var ps = new ControlSheet();
+
+		ps.AddProperty( this, x => x.Zoom );
+
+		popup.Layout.Add( ps );
+		popup.MaximumWidth = 300;
+		popup.Show();
+		popup.Position = parent.ScreenRect.TopRight - popup.Size;
+		popup.ConstrainToScreen();
+
+	}
+
+	public override async Task InitializeAsset()
+	{
+		await Task.Yield();
+
+		using ( Scene.Push() )
+		{
+			PrimaryObject = new()
+			{
+				WorldTransform = Transform.Zero
+			};
+
+			var plane = PrimaryObject.AddComponent<ModelRenderer>();
+			plane.Model = Model.Plane;
+			plane.LocalScale = new Vector3( 1, 1, 1 );
+			plane.MaterialOverride = Material.Load( "materials/dev/reflectivity_30.vmat" );
+			plane.Tint = new Color( 0.02f, 0.04f, 0.03f );
+
+			var bounds = PrimaryObject.GetBounds();
+			SceneCenter = bounds.Center;
+			SceneSize = bounds.Size;
+		}
+
+		return;
+	}
+	public override void UpdateScene( float cycle, float timeStep )
+	{
+		if ( !Widget.IsValid() )
+			return;
+
+		Camera.WorldPosition = Vector3.Up * 300;
+		Camera.Orthographic = true;
+		Camera.WorldRotation = new Angles( 90, 0, 0 );
+
+		var bitmap = new Bitmap( 512, 512 );
+
+		Draw( bitmap );
+
+		texture.Clear( Color.Black );
+		//texture.Update( bitmap );
+		DebugOverlaySystem.Current.Texture( texture, new Rect( 0, Widget.Size ) );
+
+		FrameScene();
+	}
+
+	private readonly List<Vector2> pointCache = [];
+
+	public TirePresetPreview( Asset asset ) : base( asset )
+	{
+		texture = Texture.CreateRenderTarget().WithDynamicUsage().WithScreenFormat().WithSize( 512, 512 ).Create();
+		Tire = Asset.LoadResource<TirePreset>();
+	}
+
+	private void DrawPacejka( Bitmap bitmap )
+	{
+		var tire = Tire.Pacejka;
+		var width = bitmap.Width;
+		var height = bitmap.Height;
+
+
+		{ // draw lateral line
+			pointCache.Clear();
+
+			bitmap.SetPen( Color.Red, 1 );
+
+			for ( float x = 0; x <= 1; x += 0.01f )
+			{
+				float val = tire.PacejkaFy( x ) * Zoom;
+				pointCache.Add( new( width * x, height - height * val ) );
+			}
+
+			bitmap.DrawLines( pointCache.ToArray() );
+		}
+
+		{ // draw longitudinal line
+			pointCache.Clear();
+
+			bitmap.SetPen( Color.Green, 1 );
+
+			for ( float x = 0; x <= 1; x += 0.01f )
+			{
+				float val = tire.PacejkaFx( x ) * Zoom;
+				pointCache.Add( new( width * x, height - height * val ) );
+			}
+			bitmap.DrawLines( pointCache.ToArray() );
+		}
+
+		pointCache.Clear();
+	}
+	private void Draw( Bitmap bitmap )
+	{
+		bitmap.Clear( Color.Black );
+		bitmap.SetAntialias( true );
+		DrawPacejka( bitmap );
+	}
+}