My player controller is not working correctly

So i’vegot this code:

using UnityEngine;

public class Controller : MonoBehaviour
{
    public float maxSpeed=5f;
    public float currentSpeed;
    public float acceleration = 0.2f;
    public float deceleration;
    public float decelerationBrake;
    Rigidbody2D rb;


    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    private void Update()
    {
        float input = Input.GetAxisRaw("Horizontal");
        if (Mathf.Abs(currentSpeed) < maxSpeed && Mathf.Abs(input) > 0.01f)
        {
            currentSpeed += acceleration * input * Time.deltaTime;
        }
        else if(Mathf.Abs(Input.GetAxis("Horizontal")) < 0.01 && rb.velocity.x != 0)
        {
            float decelerationFactor;// = (input * currentSpeed > 0) ? decelerationBrake : deceleration;

            if (input * currentSpeed > 0)
            {
                // If the character is moving in the same direction as the input
                decelerationFactor = decelerationBrake;
            }
            else
            {
                // If the character is not moving in the same direction as the input
                decelerationFactor = decelerationBrake;
            }

            if (currentSpeed > 0)
            {
                currentSpeed -= decelerationFactor * Time.deltaTime;
            }
            else if (currentSpeed < 0)
            {
                currentSpeed += decelerationFactor * Time.deltaTime;
            }

            /*if (currentSpeed < 0)
            {
                currentSpeed = currentSpeed + deceleration * Time.deltaTime;
            }
            if (currentSpeed > 0)
            {
                currentSpeed = currentSpeed - deceleration * Time.deltaTime;
            }*/
        }

        Vector2 move = new Vector2(currentSpeed, rb.velocity.y);
        rb.velocity = move;
    }
}

It is… Sort of working? But not always. Sometimes player just randomly stops. And i want to implement that when input is negative and player goes positive then he would slow down faster. PLEASE help.

Its hard to tell exactly without the project and testing it, movement code can be finicky since. First things first, throw in a Debug.Log into each and every If/Else statement. Then test it and see if everything is calling when it should. From what you are saying, it probably isn’t. Try to identify exactly which conditional(s) is not calling/calling it shouldn’t.

After you’ve done that, fix it, or come back with more information to see if we can assist further.

You’re reading inputs at the same time as making decisions, and you gather “Horizontal” axis input twice… these are both recipes for chaos, confusion and crashes.

It’s always best to gather ALL input to temporary variables, then process it all at once.

Here’s a further example and discussion:

Coyote Time Jumping and disconnecting input gathering from input processing:

Whenever you need more information about what your program is doing as well as how and where it is deviating from your expectations, that means it is…

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 Debug.Log() 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 Debug.Log("Problem!",this);

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: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on 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: Unity - Manual: Debugging C# code in Unity

“When in doubt, print it out!™” - Kurt Dekker (and many others)

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

If you learn more by debugging and there is some specific thing that still seems mysterious…

How to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

This is the bare minimum of information to report:

  • what you want
  • what you tried
  • what you expected to happen
  • what actually happened, log output, variable values, and especially any errors you see
  • links to actual Unity3D documentation you used to cross-check your work (CRITICAL!!!)

The purpose of YOU providing links is to make our job easier, while simultaneously showing us that you actually put effort into the process. If you haven’t put effort into finding the documentation, why should we bother putting effort into replying?

If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: Using code tags properly

  • Do not TALK about code without posting it.
  • Do NOT post unformatted code.
  • Do NOT retype code. Use copy/paste properly using code tags.
  • Do NOT post screenshots of code.
  • Do NOT post photographs of code.
  • Do NOT attach entire scripts to your post.
  • ONLY post the relevant code, and then refer to it in your discussion.

Also, decelerationFactor is always the same regardless of the direction. Provably not the origin of your problems but most likely undesired (specially taking into account the commented-out code)

I changed it, it now looks like this:

using UnityEngine;

public class Controller : MonoBehaviour
{
    public float acceleration;
    public float maxSpeed;
    public float currentSpeed;

    Rigidbody2D rb;

    private void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    private void Update()
    {
        float input = Input.GetAxisRaw("Horizontal");

        currentSpeed += acceleration * input * Time.deltaTime;
        currentSpeed = Mathf.Clamp(currentSpeed, -maxSpeed, maxSpeed);

        rb.velocity = new Vector2(currentSpeed, rb.velocity.y);
    }
}

… but it still doesn’t work. It theoretically should. But it doesn’t. And i don’t know what to change, like there is no place to throw some Debug.Log().

So unless this is a learning exercise for school or something, I would just lean on some already built 2d platform controllers like this free one: 2D Flexible Platformer Controller | Systems | Unity Asset Store

There are also many tutorials out there to help with creating a 2d controller if you still want to “make it yourself”

saying that it doesnt work and refusing to elaborate wont lead anywhere

just follow a tutorial first and modify it from there

And “doesn’t work” STILL isn’t a useful way to communicate.

As I already posted to you above,

How to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

This is the bare minimum of information to report:

  • what you want
  • what you tried
  • what you expected to happen
  • what actually happened, log output, variable values, and especially any errors you see
  • links to actual Unity3D documentation you used to cross-check your work (CRITICAL!!!)

The purpose of YOU providing links is to make our job easier, while simultaneously showing us that you actually put effort into the process. If you haven’t put effort into finding the documentation, why should we bother putting effort into replying?

[EDIT] I don’t know i i should put it in here, or on discussions.unity.com. If so, i’m sorry for your wasted time

Ah so i see.

So: I want to have a working player controller.
I’ve tried the script I’ve shown earlier.
I expected this script to accelerate the player on input, and when input is released it should decelerate.
And it is not working as expected - sometimes it does, but usually not. It is not like it stops when some variable reaches some point, it just like does it randomly. And no errors in console.

That’s NOT DEBUGGING.

Staring at code is NOT HELPFUL.

I’ll post the simplest possible debugging for you again in the hope you actually read it.

If you know a better way to get the information, by all means use it.

Meanwhile, this is the process professional software engineers use:

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 Debug.Log() 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 Debug.Log("Problem!",this);

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: https://discussions.unity.com/t/700551 or this answer for Android: https://discussions.unity.com/t/699654

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:

https://discussions.unity.com/t/839300/3

If you are looking for how to attach an actual debugger to Unity: https://docs.unity3d.com/2021.1/Documentation/Manual/ManagedCodeDebugging.html

“When in doubt, print it out!™” - Kurt Dekker (and many others)

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

If you learn more by debugging and there is some specific thing that still seems mysterious…

How to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

This is the bare minimum of information to report:

  • what you want
  • what you tried
  • what you expected to happen
  • what actually happened, log output, variable values, and especially any errors you see
  • links to actual Unity3D documentation you used to cross-check your work (CRITICAL!!!)

The purpose of YOU providing links is to make our job easier, while simultaneously showing us that you actually put effort into the process. If you haven’t put effort into finding the documentation, why should we bother putting effort into replying?

If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: https://discussions.unity.com/t/481379

  • Do not TALK about code without posting it.
  • Do NOT post unformatted code.
  • Do NOT retype code. Use copy/paste properly using code tags.
  • Do NOT post screenshots of code.
  • Do NOT post photographs of code.
  • Do NOT attach entire scripts to your post.
  • ONLY post the relevant code, and then refer to it in your discussion.