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Question Diagonal Movement Problems

Discussion in 'Getting Started' started by Simplehiro, Sep 12, 2023.

  1. Simplehiro


    Jul 21, 2022

    I have a small issue with my diagonal movement in my 2D top-down game. I'm using the new Input System for my movement and an Animator Blendtree for animations. I want 8-directional movement for my character.

    The movement itself works well, but my main problem is that whenever I walk diagonally and release the hotkeys, the character can't maintain or store the diagonal movement. This happens because I rarely/never release the hotkeys at exactly the same time, and for a tiny moment, the game thinks I'm only moving in one direction, like up, for example. As a result, the data for the last movement isn't correct.

    I'm still quite new to Unity and programming, and I'm learning everything on my own. Maybe someone is familiar with this issue, or there might be a solution in Unity that I'm not aware of.

    Movement codesnip:

    Code (CSharp):
    1.     private void Update()
    2.     {
    3.         Animator();
    4.         Move();
    6.         mouseControl = Mouse.current.rightButton.isPressed;
    8.         if (mouseControl)
    9.         {
    10.             UpdateMouseControl();
    11.             moveSpeed = 1f;
    12.         }
    13.         else
    14.         {
    15.             UpdateVisualCubeDirection();
    16.             moveSpeed = 3f;
    17.         }
    18.     }
    19.     private void FixedUpdate()
    20.     {
    21.         if (moveDirection !=
    22.         {
    23.             lastMoveDirection = moveDirection;
    24.         }
    25.     }
    26.     private void Move()
    27.     {
    28.         smoothedMovementInput = Vector2.SmoothDamp(smoothedMovementInput, moveDirection, ref movementInputSmoothVelocity, 0.1f);
    29.         rb.velocity = smoothedMovementInput * moveSpeed;
    30.     }
    32.     private void Animator()
    33.     {
    34.         animator.SetFloat("moveDirectionX", moveDirection.x);
    35.         animator.SetFloat("moveDirectionY", moveDirection.y);
    36.         animator.SetFloat("moveMagnitude", moveDirection.magnitude);
    37.         animator.SetFloat("lastmoveDirectionX", lastMoveDirection.x);
    38.         animator.SetFloat("lastmoveDirectionY", lastMoveDirection.y);
    39.     }
    42.     private void OnMove(InputValue movementValue)
    43.     {
    44.         moveDirection = movementValue.Get<Vector2>();
    45.     }

  2. Kurt-Dekker


    Mar 16, 2013

    Excellent. That means it is...

    Time to start debugging! Here is how you can begin your exciting new debugging adventures:

    You must find a way to get the information you need in order to reason about what the problem is.

    Once you understand what the problem is, you may begin to reason about a solution to the problem.

    What is often happening in these cases is one of the following:

    - the code you think is executing is not actually executing at all
    - the code is executing far EARLIER or LATER than you think
    - the code is executing far LESS OFTEN than you think
    - the code is executing far MORE OFTEN than you think
    - the code is executing on another GameObject than you think it is
    - you're getting an error or warning and you haven't noticed it in the console window

    To help gain more insight into your problem, I recommend liberally sprinkling
    statements through your code to display information in realtime.

    Doing this should help you answer these types of questions:

    - is this code even running? which parts are running? how often does it run? what order does it run in?
    - what are the names of the GameObjects or Components involved?
    - what are the values of the variables involved? Are they initialized? Are the values reasonable?
    - are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

    Knowing this information will help you reason about the behavior you are seeing.

    You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as

    If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

    You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

    You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

    You could also just display various important quantities in UI Text elements to watch them change as you play the game.

    Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer for iOS: or this answer for Android:

    If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

    Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

    If your problem is with OnCollision-type functions, print the name of what is passed in!

    Here's an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

    "When in doubt, print it out!(tm)" - Kurt Dekker (and many others)

    Note: the
    function is an alias for Debug.Log() provided by the MonoBehaviour class.
  3. Simplehiro


    Jul 21, 2022
    Hey, so I don't have any problems with the code not working. It works fine, and thanks for the help with debugging, but I already knew that, as I mentioned. My main issue is related to releasing the hotkeys. For example, when I'm holding down W and A for movement, my character moves perfectly diagonally. When I release the hotkeys, I want to save the data from my moveDirection into the lastMoveDirection so that my animator and other systems can know what my last move direction was.

    Now, onto the problem: Releasing the W and A hotkeys often doesn't happen at exactly the same time. So, for a brief moment, W is released first, and then the move direction isn't diagonal anymore. Consequently, it saves the wrong moveDirection.

  4. Kurt-Dekker


    Mar 16, 2013
    Don't use the movement inputs to control direction unless the inputs are sufficiently large enough.

    One solution is to introduce a timer (just a float updated via Time.deltaTime) that controls things to only accept a new direction if it is asserted for long enough.

    This will also introduce this equivalent amount of time as lag in matching the animation to the direction (obviously).