so i have tried to modify the character controller that you get given with unity so it can double jump. i have the rough outlines of what to do but cant get it to work. code below.

using System; using UnityEngine; using UnityStandardAssets.CrossPlatformInput; using UnityStandardAssets.Utility; using Random = UnityEngine.Random;

namespace UnityStandardAssets.Characters.FirstPerson { [RequireComponent(typeof (CharacterController))] [RequireComponent(typeof (AudioSource))] public class FirstPersonController : MonoBehaviour { [SerializeField] private bool m_IsWalking; [SerializeField] private float m_WalkSpeed; [SerializeField] private float m_RunSpeed; [SerializeField] [Range(0f, 1f)] private float m_RunstepLenghten; [SerializeField] private float m_JumpSpeed; [SerializeField] private float m_StickToGroundForce; [SerializeField] private float m_GravityMultiplier; [SerializeField] private MouseLook m_MouseLook; [SerializeField] private bool m_UseFovKick; [SerializeField] private FOVKick m_FovKick = new FOVKick(); [SerializeField] private bool m_UseHeadBob; [SerializeField] private CurveControlledBob m_HeadBob = new CurveControlledBob(); [SerializeField] private LerpControlledBob m_JumpBob = new LerpControlledBob(); [SerializeField] private float m_StepInterval; [SerializeField] private AudioClip[] m_FootstepSounds; // an array of footstep sounds that will be randomly selected from. [SerializeField] private AudioClip m_JumpSound; // the sound played when character leaves the ground. [SerializeField] private AudioClip m_LandSound; // the sound played when character touches back on ground.

     private Camera m_Camera;
     private bool m_Jump;
     public int airJumps = 1;
     [SerializeField] private int jumpCounter = 0;
     private float m_YRotation;
     private Vector2 m_Input;
     private Vector3 m_MoveDir = Vector3.zero;
     private CharacterController m_CharacterController;
     private CollisionFlags m_CollisionFlags;
     private bool m_PreviouslyGrounded;
     private Vector3 m_OriginalCameraPosition;
     private float m_StepCycle;
     private float m_NextStep;
     private bool m_Jumping;
     private AudioSource m_AudioSource;


     // Use this for initialization
     private void Start()
     {
         m_CharacterController = GetComponent<CharacterController>();
         m_Camera = Camera.main;
         m_OriginalCameraPosition = m_Camera.transform.localPosition;
         m_FovKick.Setup(m_Camera);
         m_HeadBob.Setup(m_Camera, m_StepInterval);
         m_StepCycle = 0f;
         m_NextStep = m_StepCycle/2f;
         m_Jumping = false;
         m_AudioSource = GetComponent<AudioSource>();
         m_MouseLook.Init(transform , m_Camera.transform);
     }


     // Update is called once per frame
     private void Update()
     {
         RotateView();
         // the jump state needs to read here to make sure it is not missed
         if (!m_Jump)
         {
             m_Jump = CrossPlatformInputManager.GetButtonDown("Jump");
         }

         if (!m_PreviouslyGrounded && m_CharacterController.isGrounded)
         {
             StartCoroutine(m_JumpBob.DoBobCycle());
             PlayLandingSound();
             m_MoveDir.y = 0f;
             m_Jumping = false;
         }
         if (m_CharacterController.isGrounded && !m_Jumping) {
             jumpCounter = 0;
         }
         if (!m_CharacterController.isGrounded && !m_Jumping && m_PreviouslyGrounded)
         {
                 m_MoveDir.y = 0f;
         }

         m_PreviouslyGrounded = m_CharacterController.isGrounded;
     }


     private void PlayLandingSound()
     {
         m_AudioSource.clip = m_LandSound;
         m_AudioSource.Play();
         m_NextStep = m_StepCycle + .5f;
     }


     private void FixedUpdate()
     {
         float speed;
         GetInput(out speed);
         // always move along the camera forward as it is the direction that it being aimed at
         Vector3 desiredMove = transform.forward*m_Input.y + transform.right*m_Input.x;

         // get a normal for the surface that is being touched to move along it
         RaycastHit hitInfo;
         Physics.SphereCast(transform.position, m_CharacterController.radius, Vector3.down, out hitInfo,
                            m_CharacterController.height/2f, ~0, QueryTriggerInteraction.Ignore);
         desiredMove = Vector3.ProjectOnPlane(desiredMove, hitInfo.normal).normalized;

         m_MoveDir.x = desiredMove.x*speed;
         m_MoveDir.z = desiredMove.z*speed;


         if (m_CharacterController.isGrounded)
         {
             m_MoveDir.y = -m_StickToGroundForce;

             if (m_Jump) {
                 m_MoveDir.y = m_JumpSpeed;
                 PlayJumpSound ();
                 m_Jump = false;
                 m_Jumping = true;
                 jumpCounter ++;
                 if (m_Jumping && m_PreviouslyGrounded) {
                     if (jumpCounter < airJumps) {
                         if (m_Jump) {
                             m_MoveDir.y = m_JumpSpeed;
                             PlayJumpSound ();
                             m_Jump = false;
                             m_Jumping = true;
                             jumpCounter++;
                         }
                     }
                 }
             }
         }
         else
         {
             m_MoveDir += Physics.gravity*m_GravityMultiplier*Time.fixedDeltaTime;
         }
         m_CollisionFlags = m_CharacterController.Move(m_MoveDir*Time.fixedDeltaTime);

         ProgressStepCycle(speed);
         UpdateCameraPosition(speed);

         m_MouseLook.UpdateCursorLock();
     }


     private void PlayJumpSound()
     {
         m_AudioSource.clip = m_JumpSound;
         m_AudioSource.Play();
     }


     private void ProgressStepCycle(float speed)
     {
         if (m_CharacterController.velocity.sqrMagnitude > 0 && (m_Input.x != 0 || m_Input.y != 0))
         {
             m_StepCycle += (m_CharacterController.velocity.magnitude + (speed*(m_IsWalking ? 1f : m_RunstepLenghten)))*
                          Time.fixedDeltaTime;
         }

         if (!(m_StepCycle > m_NextStep))
         {
             return;
         }

         m_NextStep = m_StepCycle + m_StepInterval;

         PlayFootStepAudio();
     }


     private void PlayFootStepAudio()
     {
         if (!m_CharacterController.isGrounded)
         {
             return;
         }
         // pick & play a random footstep sound from the array,
         // excluding sound at index 0
         int n = Random.Range(1, m_FootstepSounds.Length);
         m_AudioSource.clip = m_FootstepSounds[n];
         m_AudioSource.PlayOneShot(m_AudioSource.clip);
         // move picked sound to index 0 so it's not picked next time
         m_FootstepSounds[n] = m_FootstepSounds[0];
         m_FootstepSounds[0] = m_AudioSource.clip;
     }


     private void UpdateCameraPosition(float speed)
     {
         Vector3 newCameraPosition;
         if (!m_UseHeadBob)
         {
             return;
         }
         if (m_CharacterController.velocity.magnitude > 0 && m_CharacterController.isGrounded)
         {
             m_Camera.transform.localPosition =
                 m_HeadBob.DoHeadBob(m_CharacterController.velocity.magnitude +
                                   (speed*(m_IsWalking ? 1f : m_RunstepLenghten)));
             newCameraPosition = m_Camera.transform.localPosition;
             newCameraPosition.y = m_Camera.transform.localPosition.y - m_JumpBob.Offset();
         }
         else
         {
             newCameraPosition = m_Camera.transform.localPosition;
             newCameraPosition.y = m_OriginalCameraPosition.y - m_JumpBob.Offset();
         }
         m_Camera.transform.localPosition = newCameraPosition;
     }


     private void GetInput(out float speed)
     {
         // Read input
         float horizontal = CrossPlatformInputManager.GetAxis("Horizontal");
         float vertical = CrossPlatformInputManager.GetAxis("Vertical");

         bool waswalking = m_IsWalking;

if !MOBILE_INPUT

        // On standalone builds, walk/run speed is modified by a key press.
         // keep track of whether or not the character is walking or running
         m_IsWalking = !Input.GetKey(KeyCode.LeftShift);

endif

        // set the desired speed to be walking or running
         speed = m_IsWalking ? m_WalkSpeed : m_RunSpeed;
         m_Input = new Vector2(horizontal, vertical);

         // normalize input if it exceeds 1 in combined length:
         if (m_Input.sqrMagnitude > 1)
         {
             m_Input.Normalize();
         }

         // handle speed change to give an fov kick
         // only if the player is going to a run, is running and the fovkick is to be used
         if (m_IsWalking != waswalking && m_UseFovKick && m_CharacterController.velocity.sqrMagnitude > 0)
         {
             StopAllCoroutines();
             StartCoroutine(!m_IsWalking ? m_FovKick.FOVKickUp() : m_FovKick.FOVKickDown());
         }
     }


     private void RotateView()
     {
         m_MouseLook.LookRotation (transform, m_Camera.transform);
     }


     private void OnControllerColliderHit(ControllerColliderHit hit)
     {
         Rigidbody body = hit.collider.attachedRigidbody;
         //dont move the rigidbody if the character is on top of it
         if (m_CollisionFlags == CollisionFlags.Below)
         {
             return;
         }

         if (body == null || body.isKinematic)
         {
             return;
         }
         body.AddForceAtPosition(m_CharacterController.velocity*0.1f, hit.point, ForceMode.Impulse);
     }
 }

}