Why does my Hover Car start gaining height at high speeds?

Physics
1

Hello there guys.
I am relatively new to Unity and I just started following some of the Unity Youtube Tutorials. So I followed this tutorial about creating a simple Hover Car and then I started playing around with the values. I noticed that when I make the speed variable higher, the car slowly gains height when driving.

Here is the code:

using UnityEngine;
using System.Collections;

public class HoverMotor : MonoBehaviour {

    public float speed = 90f;
    public float turnspeed = 5f;
    public float hoverForce = 65f;
    public float hoverHeight = 2f;

    private float powerInput;
    private float turnInput;
    private Rigidbody carRigidbody;

   
    void Awake () {

        carRigidbody = GetComponent<Rigidbody>();

    }
   
    // Update is called once per frame
    void Update ()
    {
        powerInput = Input.GetAxis("Vertical");
        turnInput = Input.GetAxis("Horizontal");
    }

    void FixedUpdate()
    {
        Ray ray = new Ray(transform.position, -transform.up);
        RaycastHit hit;

        if (Physics.Raycast(ray, out hit, hoverHeight))
        {
            float proportionalHeight = (hoverHeight - hit.distance) / hoverHeight;
            Vector3 appliedHoverForce = Vector3.up * proportionalHeight * hoverForce;
            carRigidbody.AddForce(appliedHoverForce, ForceMode.Acceleration);
        }

        carRigidbody.AddRelativeForce(0f, 0f, powerInput * speed);

        carRigidbody.AddRelativeTorque(0f, turnInput * turnspeed, 0f);
    }
}

I am thankfull for any help and I hope I can learn something today :slight_smile:

2

One thing you probably want to check world down rather than transform.down (-transform.up).

Ray ray = newRay(transform.position, -Vector3.up);

As for the other problem, I would suggest you clamp the proportional height value so it never exceeds a maximum (which I assume is probably 1)