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Question Jump height lowers whenever the scene is reloaded when using an input.

Discussion in 'Scripting' started by JO_cap, Dec 1, 2023.

  1. JO_cap


    Jun 21, 2023
    Hi, Im currently working through the unity learn tutorials specifically junior programmer unit 3.

    I want to add a restart function on the said project but whenever I reset the scene using an input, the game restarts but the jump height of the player lowers. Restarting the game within the editor works fine though.

    The code specifically for restarting the game is shown below. I can provide the whole script if needed.

    Code (CSharp):
    1.    //restart the game when "R" is pressed
    2.    if (isGameOver && Input.GetKeyDown(KeyCode.R))
    3.    {
    4.        isGameOver = false;
    5.        SceneManager.LoadScene(SceneManager.GetActiveScene().name);
    6.    }
  2. Kurt-Dekker


    Mar 16, 2013
    Did you change your gravity during the game? If so, change it back.

    Make sure you also handled Time.deltaTime properly if YOU are doing the movement.

    Otherwise start debugging things related to jumping: forces, velocities, masses, gravity, etc.

    Print it all out, see how it is different on the subsequent run.

    Time to start debugging!

    By debugging you can find out exactly what your program is doing so you can fix it.

    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:

    If you are looking for how to attach an actual debugger to Unity:

    "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. JO_cap


    Jun 21, 2023
    Hi Kurt,
    If you meant during play mode, then I did not.
    For my player movement script, I only have one input and it is spacebar to jump but it's using ForceMode not time.deltaTime
    Code (CSharp):
    1.  playerRB.AddForce(Vector3.up * jumpForce, ForceMode.Impulse);
    I tried following what you said, putting Debug.Log() on my only variables that are editable like, jumpForce and gravityModifier and also the position of some stuff at the start of the game, but I get the same result every time.
    Code (CSharp):
    1.         Debug.Log($"JumpForce = {jumpForce}");
    2.         Debug.Log($"Gravity = {gravityModifier}");
    3.         Debug.Log($"Player Position = {gameObject.transform.position.ToString()}");
    4.         Debug.Log($"Player RB Position = {playerRB.position.ToString()}");
    As you can see, i tried to check for the rigidbody position (playerRB) because I notice that every time I restart using user input, the player character sinks bit by bit until it totally goes through and falls of the ground.

    I still have no idea how to fix it though.

    Anyway, I appreciate that you take some time to write all that. There are some more units on the tutorials so I guess I'll work through those for the mean time so I can get some exposure? or experience rather getting stuck on this one problem. I'll try to use what you wrote about debugging when I try to recreate this game by myself when I finish the tutorials. Thank you!
  4. Kurt-Dekker


    Mar 16, 2013
    This seems like a decent strategy.

    You'll never be exposed to it "all at once."

    You just kinda have to take a little bit each day, chip chip chip.

    Like, replace your character (temporarily) with a box that has code to always jump the same height. Does the problem persist? Or is it only to do with your player? etc.

    Check out how this guy does it:

    Imphenzia: How Did I Learn To Make Games: