Mobile Touch Input Joystick in Unity 3D

Mobile Touch Input Joystick in Unity 3D

by NSDG • Jan 7, 2019 • 0 Comments
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Unlike Desktop or Console games, Mobile games are controlled solely through the touch gestures.

So to make a controllable character in mobile game, one need to add buttons that are visually represented on the screen and are responsive to the touch input.

In this tutorial I will be showing how to create a joystick-like button in Unity 3D, which is primarily suitable for the movement control on the touchscreen phones.
You can also use the example below to add more buttons and joysticks. So let's begin!



Step 1: Create all the necessary scripts


This tutorial feature 2 scripts:

MobileJoystick_UI.cs
using UnityEngine;
using UnityEngine.UI;

public class MobileJoystick_UI : MonoBehaviour
{

    //Mobile controller graphics
    public Sprite navigationCircle;
    public Sprite navigationButton;
    //Use this in your movement script for the input control
    public Vector2 moveDirection;
    //Joystick components size
    int circleSize = 120;
    int buttonSize = 100;
    //How far the joystick should be placed from the side of the screen
    int marginLeft = 100;
    //How far the joystick should be placed from the bottom of the screen
    int marginBottom = 100;

    Canvas mainCanvas;

    //Mobile movement
    [System.Serializable]
    public class JoystickButton
    {
        public Image backgroundCircle;
        public Image mainButton;
        public Rect defaultArea;
        public Vector2 touchOffset;
        public Vector2 currentTouchPos;
        public int touchID;
        public bool isActive = false;
    }

    //Move joystick data
    JoystickButton moveTouch = new JoystickButton();

    public static MobileJoystick_UI instance;

    // Start is called before the first frame update
    void Start()
    {
        if (instance != null)
        {
            //There is another instance already present, remove this one
            Destroy(gameObject);
            return;
        }
        //Assign this instance to a static variable so you can access the movement direction directly at MobileJoystick_UI.instance.moveDirection
        instance = this;

        //This function will initialize canvas element along with the joystick button
        GameObject tmpObj = new GameObject("Canvas");
        tmpObj.transform.position = Vector3.zero;
        mainCanvas = tmpObj.AddComponent<Canvas>();
        mainCanvas.renderMode = RenderMode.ScreenSpaceOverlay;
        mainCanvas.pixelPerfect = true;

        //Add Canvas Scaler component
        CanvasScaler canvasScaled = tmpObj.AddComponent<CanvasScaler>();
        canvasScaled.scaleFactor = 1;
        canvasScaled.referencePixelsPerUnit = 100;

        //Add Graphic Raycaster element
        tmpObj.AddComponent<GraphicRaycaster>();

        //Setup navigation background
        GameObject cntrlTmpObj = new GameObject("Movement Circle");
        cntrlTmpObj.transform.position = Vector3.zero;
        cntrlTmpObj.transform.parent = tmpObj.transform;
        moveTouch.backgroundCircle = cntrlTmpObj.AddComponent<Image>();
        moveTouch.backgroundCircle.sprite = navigationCircle;
        moveTouch.backgroundCircle.rectTransform.anchorMin = new Vector2(0, 0);
        moveTouch.backgroundCircle.rectTransform.anchorMax = new Vector2(0, 0);
        moveTouch.backgroundCircle.rectTransform.sizeDelta = new Vector2(circleSize, circleSize);
        moveTouch.backgroundCircle.rectTransform.pivot = new Vector2(0, 0);
        moveTouch.backgroundCircle.rectTransform.position = new Vector3(marginLeft, marginBottom, 0);

        //Navigation button
        cntrlTmpObj = new GameObject("Movement Button");
        cntrlTmpObj.transform.position = Vector3.zero;
        cntrlTmpObj.transform.parent = tmpObj.transform;
        moveTouch.mainButton = cntrlTmpObj.AddComponent<Image>();
        moveTouch.mainButton.sprite = navigationButton;
        moveTouch.mainButton.rectTransform.anchorMin = new Vector2(0, 0);
        moveTouch.mainButton.rectTransform.anchorMax = new Vector2(0, 0);
        moveTouch.mainButton.rectTransform.sizeDelta = new Vector2(buttonSize, buttonSize);
        moveTouch.mainButton.rectTransform.pivot = new Vector2(0, 0);
        moveTouch.mainButton.rectTransform.position = new Vector3(marginLeft + (circleSize - buttonSize) / 2, marginBottom + (circleSize - buttonSize) / 2, 0);

        //Save the default location of the joystick button to be used later for input detection
        moveTouch.defaultArea = new Rect(moveTouch.mainButton.rectTransform.position.x,
            moveTouch.mainButton.rectTransform.position.y,
            moveTouch.mainButton.rectTransform.sizeDelta.x,
            moveTouch.mainButton.rectTransform.sizeDelta.y);
    }

    // Update is called once per frame
    void Update()
    {
        //Handle joystick movement
#if (UNITY_ANDROID || UNITY_IOS || UNITY_WP8 || UNITY_WP8_1) && !UNITY_EDITOR
        //Mobile touch input
        for (var i = 0; i < Input.touchCount; ++i)
        {
            Touch touch = Input.GetTouch(i);

            if (touch.phase == TouchPhase.Began)
            {
                MobileButtonsCheck(new Vector2(touch.position.x, Screen.height - touch.position.y), touch.fingerId);
            }

            if (touch.phase == TouchPhase.Moved )
            {
                if(moveTouch.isActive && moveTouch.touchID == touch.fingerId)
                {
                    moveTouch.currentTouchPos = touch.position;
                }
            }

            if (touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled)
            {
                MobileButtonStop(touch.fingerId);
            }
        }
#else
        //Desktop mouse input for editor testing
        if (Input.GetMouseButtonDown(0))
        {
            MobileButtonsCheck(new Vector2(Input.mousePosition.x, Screen.height - Input.mousePosition.y), -1);
        }

        if (Input.GetMouseButtonUp(0))
        {
            MobileButtonStop(-1);
        }

        moveTouch.currentTouchPos = Input.mousePosition;
#endif

        //Moving
        if (moveTouch.isActive)
        {
            moveTouch.mainButton.rectTransform.position = new Vector3(moveTouch.currentTouchPos.x - moveTouch.touchOffset.x, moveTouch.currentTouchPos.y - moveTouch.touchOffset.y);
            moveDirection.x = moveTouch.mainButton.rectTransform.position.x - moveTouch.defaultArea.x;
            moveDirection.y = moveTouch.mainButton.rectTransform.position.y - moveTouch.defaultArea.y;

            if (Mathf.Abs(moveDirection.x) < 19)
            {
                moveDirection.x = 0;
            }
            else
            {
                moveDirection.x = Mathf.Clamp(moveDirection.x / 75.000f, -1.000f, 1.000f);
            }

            if (Mathf.Abs(moveDirection.y) < 19)
            {
                moveDirection.y = 0;
            }
            else
            {
                moveDirection.y = Mathf.Clamp(moveDirection.y / 75.000f, -1.000f, 1.000f);
            }
        }
        else
        {
            moveTouch.mainButton.rectTransform.position = new Vector3(moveTouch.defaultArea.x, moveTouch.defaultArea.y);
            moveDirection = Vector2.zero;
        }
    }

    //Here we check if the clicked/tapped position is inside the joystick button
    void MobileButtonsCheck(Vector2 touchPos, int touchID)
    {
        //Move controller
        if (moveTouch.defaultArea.Contains(new Vector2(touchPos.x, Screen.height - touchPos.y)) && !moveTouch.isActive)
        {
            moveTouch.isActive = true;
            moveTouch.touchOffset = new Vector2(touchPos.x - moveTouch.defaultArea.x, Screen.height - touchPos.y - moveTouch.defaultArea.y);
            moveTouch.currentTouchPos = new Vector2(touchPos.x, Screen.height - touchPos.y);
            moveTouch.touchID = touchID;
        }
    }

    //Here we release the previously active joystick if we release the mouse button/finger from the screen
    void MobileButtonStop(int touchID)
    {
        if (moveTouch.isActive && moveTouch.touchID == touchID)
        {
            moveTouch.isActive = false;
            moveTouch.touchOffset = Vector2.zero;
            moveTouch.touchID = -1;
        }
    }
}

TouchPlayerController.cs
using UnityEngine;

public class TouchPlayerController : MonoBehaviour
{

    // Update is called once per frame
    void Update()
    {
        //Move Front/Back
        if (MobileJoystick_UI.instance.moveDirection.y != 0)
        {
            transform.Translate(transform.forward * Time.deltaTime * 2.45f * MobileJoystick_UI.instance.moveDirection.y, Space.World);
        }

        //Rotate Left/Right
        if (MobileJoystick_UI.instance.moveDirection.x != 0)
        {
            transform.Rotate(new Vector3(0, 14, 0) * Time.deltaTime * 4.5f * MobileJoystick_UI.instance.moveDirection.x, Space.Self);
        }
    }
}



Step 2: Now let's setup a simple scene using the scripts above


  • Create new Scene
  • Create new GameObject and call it '_TouchInput'
  • Assign MobileJoystick_UI script to it
  • Assign 'Navigation Circle' and 'Navigation button' variables.

You can use the sprites below or click here:



  • After importing them to Unity, make sure to change the Texture type to 'Sprite (2D and UI)'



Step 3: Setup player instance


Lastly we setup the player instance (In my case it will be a simple GameObject with a Cylinder inside it):

  • Create a new GameObject and call it 'MobilePlayer'
  • Add a TouchPlayerController script to it
  • Create a new Cylinder and scale it's height down until it looks almost flat (In my case the scale is (x: 1 y: 0.0142 z: 1))
  • Move Cylinder inside the 'MobilePlayer' GameObject
  • For testing purposes you can also move the Main Camera inside the 'MobilePlayer' and rotate it so it's pointed at the player like this:



Now it's time to press Play and see if everything works Ok.
NOTE: The MobileJoystick_UI script supports both mobile touch input and a mouse click (if you play in the editor).



Everything works as expected! The player is controlled by moving the joystick button around.

Interested in obtaining the source project of this tutorial? Click here