Unity Veichles Sync

I’m making a multiplayer FPS when players can get in and out of cars, but i cant figure out how to make the car sync with evey clients, if is the host that is driving it i dont have problems with sync, but when its the client the car just doesnt move neither on host side or client side.
The scripts that i used to make the car run are the Standarts Assets.
I realy need help on this guys.

using System;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;
using UnityEngine.Networking;

namespace UnityStandardAssets.Vehicles.Car
{
    [RequireComponent(typeof (CarController))]
    public class CarUserControl : NetworkBehaviour
    {

        public truckController Truck;
        private CarController m_Car; // the car controller we want to use

        private void Awake()
        {
            // get the car controller
            m_Car = GetComponent<CarController>();
        }

        private void FixedUpdate()
        {
            if (Truck.isCarActive == true) {
                // pass the input to the car!
                float h = CrossPlatformInputManager.GetAxis("Horizontal");
                float v = CrossPlatformInputManager.GetAxis("Vertical");
                #if !MOBILE_INPUT
                float handbrake = CrossPlatformInputManager.GetAxis("Jump");
                m_Car.Move(h, v, v, handbrake);
                #else
                m_Car.Move(h, v, v, 0f);
                #endif
            }

       
        }
    }
}

////////////////////////


using System;
using UnityEngine;
using UnityEngine.Networking;
namespace UnityStandardAssets.Vehicles.Car
{
    internal enum CarDriveType
    {
        FrontWheelDrive,
        RearWheelDrive,
        FourWheelDrive
    }

    internal enum SpeedType
    {
        MPH,
        KPH
    }

    public class CarController : NetworkBehaviour
    {
        [SerializeField] private CarDriveType m_CarDriveType = CarDriveType.FourWheelDrive;
        [SerializeField] private WheelCollider[] m_WheelColliders = new WheelCollider[4];
        //[SerializeField] private GameObject[] m_WheelMeshes = new GameObject[4];
       // [SerializeField] private WheelEffects[] m_WheelEffects = new WheelEffects[4];
        [SerializeField] private Vector3 m_CentreOfMassOffset;
        [SerializeField] private float m_MaximumSteerAngle;
        [Range(0, 1)] [SerializeField] private float m_SteerHelper; // 0 is raw physics , 1 the car will grip in the direction it is facing
        [Range(0, 1)] [SerializeField] private float m_TractionControl; // 0 is no traction control, 1 is full interference
        [SerializeField] private float m_FullTorqueOverAllWheels;
        [SerializeField] private float m_ReverseTorque;
        [SerializeField] private float m_MaxHandbrakeTorque;
        [SerializeField] private float m_Downforce = 100f;
        [SerializeField] private SpeedType m_SpeedType;
        [SerializeField] private float m_Topspeed = 200;
        [SerializeField] private static int NoOfGears = 5;
        [SerializeField] private float m_RevRangeBoundary = 1f;
        [SerializeField] private float m_SlipLimit;
        [SerializeField] private float m_BrakeTorque;

        private Quaternion[] m_WheelMeshLocalRotations;
        private Vector3 m_Prevpos, m_Pos;
        private float m_SteerAngle;
        private int m_GearNum;
        private float m_GearFactor;
        private float m_OldRotation;
        private float m_CurrentTorque;
        private Rigidbody m_Rigidbody;
        private const float k_ReversingThreshold = 0.01f;

        public bool Skidding { get; private set; }
        public float BrakeInput { get; private set; }
        public float CurrentSteerAngle{ get { return m_SteerAngle; }}
        public float CurrentSpeed{ get { return m_Rigidbody.velocity.magnitude*2.23693629f; }}
        public float MaxSpeed{get { return m_Topspeed; }}
        public float Revs { get; private set; }
        public float AccelInput { get; private set; }


        // Use this for initialization
        private void Start()
        {
            m_WheelMeshLocalRotations = new Quaternion[4];
            for (int i = 0; i < 4; i++)
            {
              //  m_WheelMeshLocalRotations[i] = m_WheelMeshes[i].transform.localRotation;
            }
            m_WheelColliders[0].attachedRigidbody.centerOfMass = m_CentreOfMassOffset;

            m_MaxHandbrakeTorque = float.MaxValue;

            m_Rigidbody = GetComponent<Rigidbody>();
            m_CurrentTorque = m_FullTorqueOverAllWheels - (m_TractionControl*m_FullTorqueOverAllWheels);
        }


        private void GearChanging()
        {
            float f = Mathf.Abs(CurrentSpeed/MaxSpeed);
            float upgearlimit = (1/(float) NoOfGears)*(m_GearNum + 1);
            float downgearlimit = (1/(float) NoOfGears)*m_GearNum;

            if (m_GearNum > 0 && f < downgearlimit)
            {
                m_GearNum--;
            }

            if (f > upgearlimit && (m_GearNum < (NoOfGears - 1)))
            {
                m_GearNum++;
            }
        }


        // simple function to add a curved bias towards 1 for a value in the 0-1 range
        private static float CurveFactor(float factor)
        {
            return 1 - (1 - factor)*(1 - factor);
        }


        // unclamped version of Lerp, to allow value to exceed the from-to range
        private static float ULerp(float from, float to, float value)
        {
            return (1.0f - value)*from + value*to;
        }


        private void CalculateGearFactor()
        {
            float f = (1/(float) NoOfGears);
            // gear factor is a normalised representation of the current speed within the current gear's range of speeds.
            // We smooth towards the 'target' gear factor, so that revs don't instantly snap up or down when changing gear.
            var targetGearFactor = Mathf.InverseLerp(f*m_GearNum, f*(m_GearNum + 1), Mathf.Abs(CurrentSpeed/MaxSpeed));
            m_GearFactor = Mathf.Lerp(m_GearFactor, targetGearFactor, Time.deltaTime*5f);
        }


        private void CalculateRevs()
        {
            // calculate engine revs (for display / sound)
            // (this is done in retrospect - revs are not used in force/power calculations)
            CalculateGearFactor();
            var gearNumFactor = m_GearNum/(float) NoOfGears;
            var revsRangeMin = ULerp(0f, m_RevRangeBoundary, CurveFactor(gearNumFactor));
            var revsRangeMax = ULerp(m_RevRangeBoundary, 1f, gearNumFactor);
            Revs = ULerp(revsRangeMin, revsRangeMax, m_GearFactor);
        }


        public void Move(float steering, float accel, float footbrake, float handbrake)
        {
            for (int i = 0; i < 4; i++)
            {
                Quaternion quat;
                Vector3 position;
                m_WheelColliders[i].GetWorldPose(out position, out quat);
                //m_WheelMeshes[i].transform.position = position;
                //m_WheelMeshes[i].transform.rotation = quat;
            }

            //clamp input values
            steering = Mathf.Clamp(steering, -1, 1);
            AccelInput = accel = Mathf.Clamp(accel, 0, 1);
            BrakeInput = footbrake = -1*Mathf.Clamp(footbrake, -1, 0);
            handbrake = Mathf.Clamp(handbrake, 0, 1);

            //Set the steer on the front wheels.
            //Assuming that wheels 0 and 1 are the front wheels.
            m_SteerAngle = steering*m_MaximumSteerAngle;
            m_WheelColliders[0].steerAngle = m_SteerAngle;
            m_WheelColliders[1].steerAngle = m_SteerAngle;

            SteerHelper();
            rpcApplyDrive(accel, footbrake);
            CapSpeed();

            //Set the handbrake.
            //Assuming that wheels 2 and 3 are the rear wheels.
            if (handbrake > 0f)
            {
                var hbTorque = handbrake*m_MaxHandbrakeTorque;
                m_WheelColliders[2].brakeTorque = hbTorque;
                m_WheelColliders[3].brakeTorque = hbTorque;
            }


            CalculateRevs();
            GearChanging();

            AddDownForce();
            CheckForWheelSpin();
            TractionControl();

        }


        private void CapSpeed()
        {
            float speed = m_Rigidbody.velocity.magnitude;
            switch (m_SpeedType)
            {
                case SpeedType.MPH:

                    speed *= 2.23693629f;
                    if (speed > m_Topspeed)
                        m_Rigidbody.velocity = (m_Topspeed/2.23693629f) * m_Rigidbody.velocity.normalized;
                    break;

                case SpeedType.KPH:
                    speed *= 3.6f;
                    if (speed > m_Topspeed)
                        m_Rigidbody.velocity = (m_Topspeed/3.6f) * m_Rigidbody.velocity.normalized;
                    break;
            }
        }


        private void rpcApplyDrive(float accel, float footbrake)
        {

            float thrustTorque;
            switch (m_CarDriveType)
            {
                case CarDriveType.FourWheelDrive:
                    thrustTorque = accel * (m_CurrentTorque / 4f);
                    for (int i = 0; i < 4; i++)
                    {
                        m_WheelColliders[i].motorTorque = thrustTorque;
				
                    }
                    break;

                case CarDriveType.FrontWheelDrive:
                    thrustTorque = accel * (m_CurrentTorque / 2f);
                    m_WheelColliders[0].motorTorque = m_WheelColliders[1].motorTorque = thrustTorque;
                    break;

                case CarDriveType.RearWheelDrive:
                    thrustTorque = accel * (m_CurrentTorque / 2f);
                    m_WheelColliders[2].motorTorque = m_WheelColliders[3].motorTorque = thrustTorque;
                    break;

            }

            for (int i = 0; i < 4; i++)
            {
                if (CurrentSpeed > 5 && Vector3.Angle(transform.forward, m_Rigidbody.velocity) < 50f)
                {
                    m_WheelColliders[i].brakeTorque = m_BrakeTorque*footbrake;
                }
                else if (footbrake > 0)
                {
                    m_WheelColliders[i].brakeTorque = 0f;
                    m_WheelColliders[i].motorTorque = -m_ReverseTorque*footbrake;
                }
            }
        }


        private void SteerHelper()
        {
            for (int i = 0; i < 4; i++)
            {
                WheelHit wheelhit;
                m_WheelColliders[i].GetGroundHit(out wheelhit);
                if (wheelhit.normal == Vector3.zero)
                    return; // wheels arent on the ground so dont realign the rigidbody velocity
            }

            // this if is needed to avoid gimbal lock problems that will make the car suddenly shift direction
            if (Mathf.Abs(m_OldRotation - transform.eulerAngles.y) < 10f)
            {
                var turnadjust = (transform.eulerAngles.y - m_OldRotation) * m_SteerHelper;
                Quaternion velRotation = Quaternion.AngleAxis(turnadjust, Vector3.up);
                m_Rigidbody.velocity = velRotation * m_Rigidbody.velocity;
            }
            m_OldRotation = transform.eulerAngles.y;
        }


        // this is used to add more grip in relation to speed
        private void AddDownForce()
        {
            m_WheelColliders[0].attachedRigidbody.AddForce(-transform.up*m_Downforce*
                                                         m_WheelColliders[0].attachedRigidbody.velocity.magnitude);
        }


        // checks if the wheels are spinning and is so does three things
        // 1) emits particles
        // 2) plays tiure skidding sounds
        // 3) leaves skidmarks on the ground
        // these effects are controlled through the WheelEffects class
        private void CheckForWheelSpin()
        {
            // loop through all wheels
            for (int i = 0; i < 4; i++)
            {
                WheelHit wheelHit;
                m_WheelColliders[i].GetGroundHit(out wheelHit);

                // is the tire slipping above the given threshhold
                if (Mathf.Abs(wheelHit.forwardSlip) >= m_SlipLimit || Mathf.Abs(wheelHit.sidewaysSlip) >= m_SlipLimit)
                {
                  //  m_WheelEffects[i].EmitTyreSmoke();

                    // avoiding all four tires screeching at the same time
                    // if they do it can lead to some strange audio artefacts
                    if (!AnySkidSoundPlaying())
                    {
                      //  m_WheelEffects[i].PlayAudio();
                    }
                    continue;
                }

                // if it wasnt slipping stop all the audio
                //if (m_WheelEffects[i].PlayingAudio)
               // {
               //     m_WheelEffects[i].StopAudio();
              //  }
                // end the trail generation
              //  m_WheelEffects[i].EndSkidTrail();
            }
        }

        // crude traction control that reduces the power to wheel if the car is wheel spinning too much
        private void TractionControl()
        {
            WheelHit wheelHit;
            switch (m_CarDriveType)
            {
                case CarDriveType.FourWheelDrive:
                    // loop through all wheels
                    for (int i = 0; i < 4; i++)
                    {
                        m_WheelColliders[i].GetGroundHit(out wheelHit);

                        AdjustTorque(wheelHit.forwardSlip);
                    }
                    break;

                case CarDriveType.RearWheelDrive:
                    m_WheelColliders[2].GetGroundHit(out wheelHit);
                    AdjustTorque(wheelHit.forwardSlip);

                    m_WheelColliders[3].GetGroundHit(out wheelHit);
                    AdjustTorque(wheelHit.forwardSlip);
                    break;

                case CarDriveType.FrontWheelDrive:
                    m_WheelColliders[0].GetGroundHit(out wheelHit);
                    AdjustTorque(wheelHit.forwardSlip);

                    m_WheelColliders[1].GetGroundHit(out wheelHit);
                    AdjustTorque(wheelHit.forwardSlip);
                    break;
            }
        }


        private void AdjustTorque(float forwardSlip)
        {
            if (forwardSlip >= m_SlipLimit && m_CurrentTorque >= 0)
            {
                m_CurrentTorque -= 10 * m_TractionControl;
            }
            else
            {
                m_CurrentTorque += 10 * m_TractionControl;
                if (m_CurrentTorque > m_FullTorqueOverAllWheels)
                {
                    m_CurrentTorque = m_FullTorqueOverAllWheels;
                }
            }
        }


        private bool AnySkidSoundPlaying()
        {
            for (int i = 0; i < 4; i++)
            {
              //  if (m_WheelEffects[i].PlayingAudio)
                //{
               //     return true;
               // }
            }
            return false;
        }


    }
}

You need to read about the concept of “Authority” in unity, wrt game objects. The car is probably authoritative on the HOST and so the client doesn’t have the authority to control it. There is a section in the UNET docs about it.

Good luck!

1 Like

ok 'im going to check that out, thx for the reply