Help Regarding on Fuel Bar Refuelling.

Questions & Answers
1

Hello Good Day. i am wondering how can i make my fuel bar not refuel instantly every time it touches the ground. what i want to make it happen is when i release the Jump Key or a certain Key for going up. it will slowly refuel. here in this code it just refuel instantly when it touches the ground. i tried Sir Helium’s Suggestion about the Co routine but i cannot make it work and still confused “Beginner”. i hope anyone can help me out . Advance thanks and God bless.

87865-fuelbar.png
87865-fuelbar.png1920×1080 311 KB

using UnityEngine;
using System.Collections;

public class Player_Controls : MonoBehaviour {

public static float jetPackFuel = 4f;
public float jetPackForce = 15.0f;
public GameObject jetPack;
private bool isGrounded = true;

// Update is called once per frame
void Update () {
	if (Input.GetButton ("Jump") && jetPackFuel >= 0.001f) {
		BoostUp ();
		jetPack.GetComponent<ParticleSystem> ().Play ();
	} else {
		jetPack.GetComponent<ParticleSystem> ().Stop ();
	}
}

void BoostUp () {
	isGrounded = false;
	jetPackFuel = Mathf.MoveTowards (jetPackFuel, 0, Time.fixedDeltaTime);
	GetComponent<Rigidbody> ().AddForce (new Vector3 (0, jetPackForce));
}

void OnCollisionEnter (Collision Col){
	if (Col.gameObject.tag == "Ground") {
		isGrounded = true;
		//CREATE METHOD HERE
		Refuel();
	}
}

void Refuel () {
	//Originally, this is only getting called once because OnCollisionEnter is only getting called once When you hit the ground
	//so to fix that we can use a while loop
	if (isGrounded == true){
		while (jetPackFuel < 2.9f){
			jetPackFuel = Mathf.MoveTowards (jetPackFuel, 3, 0.001f * Time.fixedDeltaTime);
		}
	}
}

}

2

you could have a timer that counts upwards and after its greater than a certain number then start refilling the fuel.
e.g.

float timer;

        if (isGrounded == true)
        {
            timer += 2 * Time.deltaTime;

            while (jetPackFuel < 2.9f && timer > 2)
            {
                jetPackFuel = Mathf.MoveTowards(jetPackFuel, 3, 0.001f * Time.fixedDeltaTime);
            }
        }
        if (isGrounded == false)
        {
            timer = 0;
        }

Hope this was helpful.
If it was up voting this comment will help anyone else having the same problem.

3

This should do the trick for you.

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class Player_Controls : MonoBehaviour
{

    /// <summary>
    /// The max fuel of the jetpack.
    /// </summary>
    public float MaxJetPackFuel = 4f;
    /// <summary>
    /// The speed of the jetpack.
    /// </summary>
    public float jetPackForce = 15.0f;
    /// <summary>
    /// The fuel cost per second.
    /// </summary>
    public float jetPackFuelCost = 0.25f;
    /// <summary>
    /// The fuel regen per second.
    /// </summary>
    public float jetPackFuelRegen = 0.15f;
    // The current amount of fuel.
    private float currentFuel;
    /// <summary>
    /// The Jetpack gameobject.
    /// </summary>
    public GameObject jetPack;
    /// <summary>
    /// The UI image for the fuel bar.
    /// </summary>
    public Image fuelBar;
    // Is the gameobject grounded?
    private bool isGrounded = true;
    // The particle system of the jetpack.
    private ParticleSystem jetPackParticle;
    // The rigidbody attached to the gameobject.
    private Rigidbody body;
    // OnEnable is called before Update, each time the object is enabled or loaded.
    void OnEnabie()
    {
        // Find and set our particle system.
        jetPackParticle = jetPack.GetComponent<ParticleSystem>();
        // Find and set our Rigidybody.
        body = GetComponent<Rigidbody>();
        // Set our initial fuel.
        currentFuel = MaxJetPackFuel;
        // Configure out fuel bar.
        fuelBar.type = Image.Type.Filled;
        fuelBar.fillMethod = Image.FillMethod.Horizontal;
        fuelBar.fillAmount = 1.0f;
    }
    // Update is called many times per second.
    void Update()
    {
        // If our player is pressing the jump button.
        if (Input.GetButton("Jump"))
        {
            // If our fuel is not empty.
            if (currentFuel > 0)
            {
                // Call our boost method.
                BoostUp();
                // Play our particle system.
                jetPackParticle.Play();
            }
        }
        // If the player is grounded and fuel is not max.
        else if (isGrounded && currentFuel < MaxJetPackFuel)
        {
            // Call our refuel method.
            Refuel();
        }
    }
    void BoostUp()
    {
        // If the player is on the ground.
        isGrounded = false;
        // Reduce the current fuel.
        currentFuel -= jetPackFuelCost * Time.deltaTime;
        // Add upwards velocity.
        body.velocity = Vector3.up * jetPackForce * Time.deltaTime;
        // Update our fuel bar.
        fuelBar.fillAmount = Mathf.InverseLerp(0, MaxJetPackFuel, currentFuel);
    }
    void OnCollisionEnter(Collision Col)
    {
        // If we touched the ground (usually there is a better way than to check for tags)
        if (Col.gameObject.tag == "Ground")
        {
            // Set our grounded bool to true.
            isGrounded = true;
            // Stop our particles.
            jetPackParticle.Stop();
        }
    }
    void Refuel()
    {
        // If te player is on the ground.
        if (isGrounded == true)
        {
            // If the fuel is not max.
            if (currentFuel < MaxJetPackFuel)
            {
                // Increase the current fuel.
                MaxJetPackFuel += jetPackFuelRegen * Time.deltaTime;
                // Update our fuel bar.
                fuelBar.fillAmount = Mathf.InverseLerp(0, MaxJetPackFuel, currentFuel);
            }
        }
    }
}

I optimized some of the code you were using, and notated it, I hope this help.