Jump Button Not Always Registering

[NameyMcNameFace]

Hi, I only started learning to script about a week ago so I’m honestly not too knowledgeable yet. I’ve watched a few tutorials and compiled a small 3D platforming script. I added gravity in a fixed update function so I could add a variable to better control the gravity of the player. Because of this I have turned off the gravity on the Rigidbody component. The gravity works fine, however I have started having issues with unity not always registering the jump button even if the player is grounded.

If anyone has any idea where my issue lies I would greatly appreciate the help.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(Rigidbody))]

public class PlatformController : MonoBehaviour
{
    private float h;
    private float v;
    [SerializeField] private float speed = 10f;
    private float angleSpeed = 180f;

    public bool useGravity = true;
    public float gravityModifier = 5f;
    [SerializeField] private float jumpHeight = 25f;
    private Rigidbody rb;

    void Awake()
    {
        rb = GetComponent<Rigidbody>();
    }

    void Update()
    {
        h = Input.GetAxis("Horizontal") * angleSpeed * Time.deltaTime;
        v = Input.GetAxis("Vertical") * speed * Time.deltaTime;

        transform.Translate(Vector3.forward * v);
        transform.Rotate(Vector3.up * h);
       

        if(IsGrounded() && Input.GetButtonDown("Jump"))
        {
            rb.velocity = Vector3.up * jumpHeight;
        }
    }

    void FixedUpdate()
    {
        GetComponent<Rigidbody>().useGravity = false;
        if (useGravity) GetComponent<Rigidbody>().AddForce(Physics.gravity * (GetComponent<Rigidbody>().mass * GetComponent<Rigidbody>().mass) * gravityModifier);
    }

    public bool IsGrounded()
    {
        return Physics.Raycast(transform.position, Vector3.down, 1f);
    }
}

[Kurt-Dekker]

The above is a complete mishmash of manipulating the transform directly, both rotations and positions, and setting the Rigidbody velocity, and ALSO setting force. I’m surprised anything works at all!

With Physics (or Physics2D), never manipulate the Transform directly. If you manipulate the Transform directly, you are bypassing the physics system and you can reasonably expect glitching and missed collisions and other physics mayhem.

Always use the .MovePosition() and .MoveRotation() methods on the Rigidbody (or Rigidbody2D) instance in order to move or rotate things. Doing this keeps the physics system informed about what is going on.

Collisions in high speed without unity physic / rigidbody

You say you’re not using 2D physics but you’re using queries therefore obviously colliders. This IS using 2D physics therefore you need to use it correctly so here are some basic rules: Don’t ever modify the Transform if using 2D physics components If you want a 2D Collider to move then add a Rigidbody2D and use its API to move it; many ways to do this. Rigidbody2D don’t make it “unresponsive”. If you want explicit control then set the body-type to Kinematic; it’s what it’s for. When…

OnCollisionEnter2D not being called

That’s not related to body-type. You should never drive via the Transform. The main thing to understand here is that the Rigidbody2D role is to write to the Transform after the physics simulation, not the other way around. It acts as a proxy to the Transform because you want physics behaviour. Does “it work” if you write to the Transform and force the Rigidbody2D to read from the Transform? Yes! It works like that because otherwise it’d be reported as a bug and so we’re forced to “support” it.…

[NameyMcNameFace]

@Kurt-Dekker

The above is a complete mishmash of manipulating the transform directly, both rotations and positions, and setting the Rigidbody velocity, and ALSO setting force. I’m surprised anything works at all!

With Physics (or Physics2D), never manipulate the Transform directly. If you manipulate the Transform directly, you are bypassing the physics system and you can reasonably expect glitching and missed collisions and other physics mayhem.

Always use the .MovePosition() and .MoveRotation() methods on the Rigidbody (or Rigidbody2D) instance in order to move or rotate things. Doing this keeps the physics system informed about what is going on.

https://discussions.unity.com/t/866410/5

https://discussions.unity.com/t/878046/8

Pointing me to the .MovePosition() seemed to be just what I needed. Another quick question on this however. Is it always best to put the movement in the fixed update function? While testing I saw that I needed to put “Jump” in the regular Update function in order for it to work, so I wasn’t sure if it was just the movement that should be in there.

[Kurt-Dekker]

@NameyMcNameFace

While testing I saw that I needed to put “Jump” in the regular Update function in order for it to work,

Yes, you need to “sense” the button or key down in Update() and set a boolean true.

Then in FixedUpdate you check it, operate on it (do the physics), and set the boolean false

Since you asked, here are two good discussions on Update() vs FixedUpdate() timing:

https://jacksondunstan.com/articles/4824

https://johnaustin.io/articles/2019/fix-your-unity-timestep