HOW TO CONTROL ENGINE SOUND WITH RPM IN UNITY

using UnityEngine;

[RequireComponent(typeof(AudioSource))]
public class EngineAudioController : MonoBehaviour
{
    [Header("Vehicle Reference")]
    [SerializeField] private Rigidbody targetRigidbody;
    [SerializeField] private float maxSpeedMps = 40f; // Approx 144 km/h

    [Header("Pitch Tuning")]
    [SerializeField] private float minPitch = 0.65f; // Idle sound
    [SerializeField] private float maxPitch = 2.2f;  // Redline RPM
    [SerializeField] private float pitchSmoothRate = 3.5f;

    [Header("Volume Tuning")]
    [SerializeField] private float minVolume = 0.35f;
    [SerializeField] private float maxVolume = 0.95f;

    private AudioSource audioSource;
    private float currentPitch;

    private void Awake()
    {
        audioSource = GetComponent<AudioSource>();
        audioSource.loop = true;
        audioSource.playOnAwake = true;

        if (targetRigidbody == null)
        {
            targetRigidbody = GetComponentInParent<Rigidbody>();
        }

        currentPitch = minPitch;
    }

    private void Start()
    {
        if (!audioSource.isPlaying)
        {
            audioSource.Play();
        }
    }

    private void Update()
    {
        if (targetRigidbody == null) return;

        // Calculate speed fraction between 0.0 (stopped) and 1.0 (top speed)
        float currentSpeed = targetRigidbody.linearVelocity.magnitude;
        float speedRatio = Mathf.Clamp01(currentSpeed / maxSpeedMps);

        // Calculate target pitch and volume
        float targetPitch = Mathf.Lerp(minPitch, maxPitch, speedRatio);
        float targetVolume = Mathf.Lerp(minVolume, maxVolume, speedRatio);

        // Smooth pitch transitions to avoid robotic jumps
        currentPitch = Mathf.MoveTowards(currentPitch, targetPitch, pitchSmoothRate * Time.deltaTime);

        audioSource.pitch = currentPitch;
        audioSource.volume = targetVolume;
    }
}