Shaking GameObject, moving on x-axis in endless runner style game

Hi all,

I've got an issue with a character in an Endless Runner style game, from a tutorial I found on YouTube. (Tutorial here: https://www.youtube.com/playlist?list=PLLH3mUGkfFCXQcNBz_FZDpqJfQlupTznd )

The player 'jitters' (see video) when it's not moved into the correct lane absolutely, it's immediately clear on iOS but I have noticed it occur on Android.

I've updated the Player Position into UI text objects to show the desired lane move changes, (x,y and z respectively).

The player (with a character controller attached) shakes when the player moves and doesn't reach the perfect x-axis values. -2.5, 0 or 2.5 for left, middle or right lanes.

Video (filmed on an iPhone 6, apologies for quality.) Note the X values changing rapidly when the player is shaking.

https://www.youtube.com/watch?time_continue=33&v=jrcnZTAF-CI

The jitter does stop and it often helped by moving along the Y-axis ( Jumping / Sliding in the context of the game).

Has anyone else experienced this issue? Found an elegant solution for it? I've taken a look at the following issues, but nothing I've tried has worked. https://forum.unity.com/threads/how-to-smooth-character-movement-that-is-jittery.322417/ https://forum.unity.com/threads/charactercontroller-movement-jittery.40196/

I've seen that some people experience jitters far from the origin, but this occurs close to Zero, so I've discounted that idea. I've tried updating the Updates to LateUpdate / FixedUpdate. I have changed the "Min Move Distance" on the Character Controller to no avail.

I think the key is fixing the issue is either reaching the desired lane value with a different type of Move on the Character Controller or giving it a margin or error, any ideas on how to achieve this would be great.

I've also attached my code for the playerMotor below.

Unity Version: 2019.1.0f2

PlayerMotor.cs:

     using UnityEngine;
     using UnityEngine.UI;
      
     public class PlayerMotor : MonoBehaviour
     {
         // PARAMETERS
         private const float LANE_DISTANCE = 2.5f;
         private const float TURN_SPEED = 0.05f;
      
         // BOOL
         private bool isRunning = false;
      
         // ANIMATION
         private Animator anim;
      
         // MOVEMENT
         private CharacterController controller;
         private float jumpForce = 4.0f;
         private float gravity = 12.0f;
         private float verticalVelocity;
      
         // SPEED
         private float originalSpeed = 7.0f;
         private float speed;
         private float speedIncreaseLastTick;
         private float speedIncreaseTime = 2.5f;
         private float speedIncreaseAmount = 0.1f;
      
         // DEBUG
         public Text xpos, ypos, zpos;
      
         // LANE FOR PLAYER
         private int desiredLane = 1; // 0 = Left, 1 = Middle, 2 = Right
      
         private void Start()
         {
             speed = originalSpeed;
             controller = GetComponent<CharacterController>();
             anim = GetComponent<Animator>();
         }
      
         private void Update()
         {
             // CHECK FOR BOOLEAN IN GAME MANAGER
             if (!isRunning)
                 return;
      
             if(Time.time - speedIncreaseLastTick > speedIncreaseTime){
                 speedIncreaseLastTick = Time.time;
                 speed += speedIncreaseAmount;
                 // CHANGE THE MODIFIER TEXT
                 GameManager.Instance.UpdateModifier(speed - originalSpeed);
             }
      
             if (MobileInput.Instance.SwipeLeft)
             {
                 MoveLane(false);
             }
      
             if (MobileInput.Instance.SwipeRight)
             {
                 MoveLane(true);
             }
      
             // Calculate where we should be next
             Vector3 targetPosition = transform.position.z * Vector3.forward;
      
             // SWITCH LANES
             if (desiredLane == 0)
             {
                 targetPosition += Vector3.left * LANE_DISTANCE;
                 //Debug.Log(targetPosition);
             }
             else if (desiredLane == 2)
             {
                 targetPosition += Vector3.right * LANE_DISTANCE;
                 //Debug.Log(targetPosition);
             }
      
             // THIS DIDN'T FIX IT
             // ===============================
             //switch(desiredLane){
             //    case 0:
             //        targetPosition = Vector3.left * LANE_DISTANCE;
             //        targetPosition = new Vector3(targetPosition.x, targetPosition.y, transform.position.z);
             //        break;
             //    case 1:
             //        targetPosition = Vector3.zero;
             //        targetPosition = new Vector3(targetPosition.x, targetPosition.y, transform.position.z);
             //        break;
             //    case 2:
             //        targetPosition = Vector3.right * LANE_DISTANCE;
             //        targetPosition = new Vector3(targetPosition.x, targetPosition.y, transform.position.z);
             //        break;
             //}
      
             // CALCULATE THE MOVE DELTA
             Vector3 moveVector = Vector3.zero;
      
             moveVector.x = (targetPosition - transform.position).normalized.x * speed;
      
             // DEVELOPMENT
             Vector3 playerPosition = this.transform.position;
             xpos.text = playerPosition.x.ToString();
             ypos.text = playerPosition.y.ToString();
             zpos.text = playerPosition.z.ToString();
      
             // CALL THE FUNCTION HERE AND ASSIGN TO VARIABLE SO WE'RE NOT CALCULATING TWICE
             bool isGrounded = IsGrounded();
             anim.SetBool("Grounded", isGrounded);
                
             // CALCULATE GRAVITY
             // IS CHARACTER ON THE GROUND
             if (isGrounded)
             {
                 verticalVelocity = -0.1f;
                 // IF PLAYER JUMPS
                 //if (Input.GetKeyDown(KeyCode.Space) || MobileInput.Instance.SwipeUp)
                 if (MobileInput.Instance.SwipeUp)
                 {
                     anim.SetTrigger("Jump");
                     verticalVelocity = jumpForce;
                 } else if (MobileInput.Instance.SwipeDown){
                     // SLIDE
                     StartSliding();
                     Invoke("StopSliding", 1.0f);
                 }
             }
             else
             {
                 // ALWAYS PULL THE CHARACTER DOWN
                 verticalVelocity -= (gravity * Time.deltaTime);
      
                 // FAST FALLING
                 //if (Input.GetKeyDown(KeyCode.Space) || MobileInput.Instance.SwipeDown)
                 if (MobileInput.Instance.SwipeDown)
                 {
                     verticalVelocity = -jumpForce;
                 }
             }
      
             moveVector.y = verticalVelocity;
      
             moveVector.z = speed;
      
             // USE THE MOVE DELTA AND APPLY TO CONTROLLER
             // NEED TO MOVE THE PLAYER TO MOVE VECTOR WITHIN MARGIN OF ERROR?!
             controller.Move(moveVector * Time.deltaTime);
      
             // ROTATE THE PLAYER TO WHERE HE IS GOING
             Vector3 dir = controller.velocity;
      
             if (dir != Vector3.zero)
             {
                 dir.y = 0;
                 transform.forward = Vector3.Lerp(transform.forward, dir, TURN_SPEED);
             }
      
         }
      
         private void MoveLane(bool goingRight)
         {
             // DESIRED LANE TO MOVE TO
             desiredLane += (goingRight) ? 1 : -1;
             desiredLane = Mathf.Clamp(desiredLane, 0, 2);
         }
      
         private bool IsGrounded()
         {
             Ray groundRay = new Ray(new Vector3(controller.bounds.center.x,
                                                 (controller.bounds.center.y - controller.bounds.extents.y) + 0.2f,
                                                 controller.bounds.center.z), Vector3.down);
             Debug.DrawRay(groundRay.origin, groundRay.direction, Color.cyan, 1.0f);
      
             return (Physics.Raycast(groundRay, 0.2f + 0.1f));
      
         }
      
         public void StartRunning(){
             isRunning = true;
             anim.SetTrigger("StartRunning");
         }
      
         private void StartSliding(){
             anim.SetBool("Sliding", true);
             controller.height /= 2;
             controller.center = new Vector3(controller.center.x, controller.center.y / 2, controller.center.z);
         }
      
         private void StopSliding(){
             anim.SetBool("Sliding", false);
             controller.height *= 2;
             controller.center = new Vector3(controller.center.x, controller.center.y * 2, controller.center.z);
         }
      
         private void OnControllerColliderHit(ControllerColliderHit hit)
         {
             switch(hit.gameObject.tag){
                 case "Obstacle":
                     Crash();
                 break;
             }
         }
      
         private void Crash(){
             // PLAYER DIES
             anim.SetTrigger("Death");
             isRunning = false;
             GameManager.Instance.OnDeath();
         }
      
     }