Unity3D-通过单击将对象向相反方向移动

Question

I'm new in Unity and I'm working on a simple project but I'm stuck.

So my idea is when the player touches the bottom side of a ball it goes the opposite direction. Pretty much like in real life, if you kick a ball on the bottom side it will go up, but in 2D version.

I tried finding the opposite point of where the player touched the ball and making a vector by subtracting the original point and the opposite point, and then applying force to move the ball but it doesn't work.

void MoveBall()
{
     x = mouseClickPosition.x;
     y = mouseClickPosition.y;
     oppositeClickPosition.x = -x;
     oppositeClickPosition.y = -y;
     Vector2 direction = oppositeClickPosition - mouseClickPosition;
     rb.AddForce(direction * force, ForceMode.Impulse);
}

Answer 1

You have to subtract the mousePosition and the center of the ball.

Vector3 clickedPosition = Camera.main.ScreenToWorldPoint (Input.mousePosition);
Vector3 ballCenter = ballTransform.position;

// If this goes the opposite direction just swap the values.
Vector3 forceDirection = (ballCenter  - clickedPosition).normalized;

ballRigidbody.AddForce (forceDirection * strength, ForceMode.Impulse);

This way you find the direction and add the force you want, you can not use the normalized Vector3 if you want to use the distance as a factor too.

And you can catch that event properly on OnMouseDown if the ball has a collider

https://docs.unity3d.com/ScriptReference/MonoBehaviour.OnMouseDown.html

Answer 2

This may be helpful: https://answers.unity.com/questions/681698/vector-between-two-objects.html It Explains how to do it in 3D but the idea applies to both.

In your case, instead of oppositeClickPosition you should use the position of the ball:

Vector2 direction = transform.position - mouseClickPosition;

(replace transform.position with the position of the ball if this script is not attatched to the ball)

Hope that helps!