2 Player Input using 1 Keyboard (split screen input)?

Unity Engine
1

EDIT: Merged vehicle 1 and vehicle 2 script in CarUserControl

I’ve done everything for split screen set up, but I cannot seem to figure out how to control two 3D vehicles (using StandardAssets) with a single keyboard (WASD / Arrow keys).

Here are my code for:

CarUserControl (from Unity Standard Assets):

[code=CSharp]using System;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;

namespace UnityStandardAssets.Vehicles.Car
{
    [RequireComponent(typeof (CarController))]
    public class CarUserControl : MonoBehaviour
    {
        private CarController m_Car; // the car we want to use controller for
        private CarController m_Car2; // the car we want to use controller for


        private void Awake()
        {
            // get the car controller script
            m_Car = GetComponent<CarController>();
            m_Car2 = GetComponent<CarController>();
        }

        //check for user input
        private void Update()
        {
            // pass the input to the car 1
            //steering
            float h = Input.GetAxis("Horizontal");
            //accel, reverse
            float v = Input.GetAxis("Vertical");

            float handbrake = Input.GetAxis("Jump");
            m_Car.Move(h, v, v, handbrake);
            m_Car.Move(h, v, v, 0f);
        
        
            // pass the input to the car 2
            //steering
            float h2 = Input.GetAxis("Horizontal2");
            //accel, reverse
            float v2 = Input.GetAxis("Vertical2");

            float handbrake2 = Input.GetAxis("Jump2");
            m_Car2.Move(h2, v2, v2, handbrake2);
            m_Car2.Move(h2, v2, v2, 0f);
        
        

        }
    }
}

[/code]

and CarController (from Unity Standard Assets)

using System;
using UnityEngine;

namespace UnityStandardAssets.Vehicles.Car
{
    internal enum CarDriveType
    {
        FrontWheelDrive,
        RearWheelDrive,
        FourWheelDrive
    }

    internal enum SpeedType
    {
        MPH,
        KPH
    }

    public class CarController : MonoBehaviour
    {
        [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();
            ApplyDrive(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 ApplyDrive(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;
        }
    }
}
2

So what’s the result of what you have? What exactly isn’t working? Have you set up all the controls you’re referencing in Project Settings->Input?

3

Vehicle 1 moves with arrow keys, but vehicle 2 stays still and does not respond.

Yes, I have set up the controls I referenced in Project Settings->Input

I set it so that the first player can use Arrow keys while player 2 can use WASD, but both don’t seem to work at once.

As shown in the code below, Standard Assets used Input.GetAxis to help achieve it. Hence, why I stuck to that.

Now in the past few hours, I made a few changes to the code and combined the first two files.

Now I’m able to get input but only the last set of instructions (for Vertical, Horizontal and Jump) that gets called is the one that responds. The ones above those, (still in FixedUpdate(); ) gets ignored completely but both cars move at once (I have included the updated CarUserControl below, in this post.

using System;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;

namespace UnityStandardAssets.Vehicles.Car
{
    [RequireComponent(typeof (CarController))]
    public class CarUserControl : MonoBehaviour
    {
        private CarController m_Car; // the car we want to use controller for
        private CarController m_Car2; // the car we want to use controller for


        private void Awake()
        {
            // get the car controller script
            m_Car = GetComponent<CarController>();
            m_Car2 = GetComponent<CarController>();
        }

        //check for user input
        private void Update()
        {
            // pass the input to the car 1
            //steering
            float h = Input.GetAxis("Horizontal");
            //accel, reverse
            float v = Input.GetAxis("Vertical");
 
            float handbrake = Input.GetAxis("Jump");
            m_Car.Move(h, v, v, handbrake);
            m_Car.Move(h, v, v, 0f);
         
         
            // pass the input to the car 2
            //steering
            float h2 = Input.GetAxis("Horizontal2");
            //accel, reverse
            float v2 = Input.GetAxis("Vertical2");
 
            float handbrake2 = Input.GetAxis("Jump2");
            m_Car2.Move(h2, v2, v2, handbrake2);
            m_Car2.Move(h2, v2, v2, 0f);
         
         
 
        }
    }
}

So now the above code here is just the first two files merged. I still use the same script for CarController.cs

4

Your moving both cars from the same inputs, unity has both wsad and the arrows by defualt on the horizontal/vertical axis.

Use a uniqe input for each car.

1 Like
5

You could also try using Input.GetKey/GetKeyDown to detect specific key presses, e.g.

left = Input.GetKey(KeyCode.LeftArrow);
right = Input.GetKey(KeyCode.RightArrow);
jump = Input.GetKeyDown(KeyCode.Space);

-Scott