CODEWITHSUNDEEP
unity-game-engine
EmreAkkoc
EmreAkkoc

Reputation: 663

AddRelativeForce() does not add the force relatively

I have want to add force to a Rigidbody by dragging mouse on the screen. even though I have transformed screen coordinates to the world coordinates and rotation of the Rigidbody looks at the coordinates where the mouse button is released, When I add relative force by AddRelativeForce ball goes directly forward.

public GameObject ballPrefab;
GameObject ballInstance;

private float force=15;
Vector3 mouseStart;
Vector3 mouseStop;
float minDragDistance=15f;
float zDepth=20f;

void FixedUpdate()
{
    if (Input.GetMouseButtonDown(0))
    {
        mouseStart = Input.mousePosition;
    }
    if (Input.GetMouseButtonUp(0))
    {
        mouseStop = Input.mousePosition;

        if(Vector3.Distance(mouseStop, mouseStart) > minDragDistance)
        {
            //Here I am getting the position on screen coordinates to throw the rigidbody to                
            Vector3 hitPos = new Vector3(Input.mousePosition.x, Input.mousePosition.y, zDepth);

            //I transform screen coordinates to world coordinates
            Vector3 hitPoss = Camera.main.ScreenToWorldPoint(hitPos);
            //transforming rigidbody to look at hitpos direction             
            ballInstance.transform.LookAt(hitPoss);
            //adding relative force
            ballInstance.GetComponent<Rigidbody>().AddRelativeForce(Vector3.forward * force, ForceMode.Force);
        }
    }
}

As I commented in the code I change the transform.rotation properties of my game object with LookAt() function and when I check the inspector it changes the rotation just right. but by AddRelativeForce(Vector3.forward) it directly goes forward on global z direction instead of locally changed z direction.

Upvotes: 0

Views: 3862

Answers (2)

Ali Baba
Ali Baba

Reputation: 349

AddRelativeForce applies a force relative to the parent object's orientation, which doesn't really make sense here, since there is no parent object. Instead of:

ballInstance.GetComponent<Rigidbody>().AddRelativeForce(Vector3.forward * force, ForceMode.Force);

Try:

ballInstance.GetComponent<Rigidbody>().AddForce(ballInstance.transform.forward * force, ForceMode.Force);

This should work, since instead of using the global forward Vector Vector3.forward, you are using the forward Vector of your ballInstance ballInstance.transform.forward

Upvotes: 1

shingo
shingo

Reputation: 27011

Changing the transform won't take effect instantly, you should set Rigidbody.rotation instead.

Check the document: https://docs.unity3d.com/ScriptReference/Rigidbody-rotation.html

Upvotes: 0

Related Questions