Move forward a sprite 2d in clicking on it in Unity 3d

Question

Unity version:2021.1.24f1

Hello, currently I am creating a 2D game with Unity 3d; I wish that when I click with my mouse and the cursor is above my sprite it goes up 15 pixels; it moves vertically and horizontally

My script:

    using UnityEngine;
    
    public class PlayerMovement : MonoBehaviour
    {
        Rigidbody m_Rigidbody;
        float m_speed;
        
    
        void Start(){
            m_Rigidbody = GetComponent<Rigidbody>();
            m_speed = 5f;
        }
    
        void Update()
        //bouton gauche de la souris
        {if (Input.GetMouseButtonDown(0)){
            m_Rigidbody.velocity = transform.forward(new Vector2(0,-1) * Time.deltaTime * m_speed, Space.World);
            
        }
        //bouton droit de la souris
        if(Input.GetMouseButtonDown(1)){
            m_Rigidbody.velocity = transform.forward(new Vector2(-1, 0) * Time.deltaTime*m_speed, Space.World);
        }
        //roulette de la souris
        if(Input.GetMouseButtonDown(2)){
            m_Rigidbody.velocity = transform.forward (new Vector2(0,-1) * Time.deltaTime * m_speed, Space.World);
        }
    
            
        }
    }```

Answer 1

One of the mistakes that you're making is that you're using a Rigidbody component in a 2D game. You should be using a Rigidbody2D component.

The other one, making the error that you stated below is that you're using transform.forward as a method, when in fact it's just a Vector3(0,0,1) . So, if you want to go up (not forward, it's 2D), just use transform.up alone, or new Vector2(0,1) without multiplying one by the other, which doesn't really make sense .

You also shouldn't modify the rb.velocity value directly and I don't know if it is even possible . There's a built-in Unity function, Rigidbody2D.AddForce(Vector2) So try using:

m_Rigidbody.AddForce(transform.up * Time.deltaTime * m_speed);

That should work. I also don't know why you are changing the velocity/force added with time, because that will make the player go faster, and faster, but it's your code.