# Move player in a circular manner

i'm creating a pong game for learning purpose and decided to have the Paddle moving freely but with a slight change in its control.

When pressing LEFT OR RIGHT it should move in polar coordinates facing the ball. And UP OR DOWN moves the paddle towards or backwards the ball.

I've spent the whole day trying out a few solutions but didn't make it.

             var ball = Vector3.zero; // target
var d = ball - translation.Value.ToVector3();
var radius = d.magnitude;

var dir = d.normalized * data.speed * deltaTime;
var angle = Vector3.Angle(ball, translation.Value);

var nextPos = translation.Value;

if (data.input.x > 0)
{
nextPos.x += dir.x + 15 * math.sin(angle) * data.speed * deltaTime;
nextPos.z += dir.z + 15 * math.cos(angle) * data.speed * deltaTime;
}

if (data.input.x < 0)
{
nextPos.x -= dir.x + 15 * math.sin(angle) * data.speed * deltaTime;
nextPos.z -= dir.z + 15 * math.cos(angle) * data.speed * deltaTime;
}

translation.Value = nextPos;


• Does transform.RotateAround() work for you? Feb 16, 2020 at 12:43
• I've tried but didn't work out. Thanks Philipp! Feb 16, 2020 at 21:24
• I am not 100% sure I understand this. When no input is provided, does the paddle just follow the ball? Or it stays put, but rotates to face the ball? Feb 17, 2020 at 9:23
• @htmlcoderexe the paddle should stay put till some input is provided. Feb 17, 2020 at 12:07
• This looks like its Unity, right? Whatever environment it is, could you add the proper tag, please? This will make it easier for others to find it later. Feb 20, 2020 at 15:51

Sorry for my initial shallow answer. After doing research, I could not find where I had found the initial Mathf.PI solution. But after fiddling around in Unity, I came up with my own solution to this problem. Here is the code below

{

public Transform ball;
public float speed = 1.0f;
private float leftToRightMovement;

/*
private float distanceFromBall;
private float offsetMultiplier;
*/

void Update()
{
//This is my attempt to control the speed of the paddle relative to the distance to the ball, but the speed kept multiplying into infinity.
/*
Vector3 offset = ball.position + transform.position;
float sqrLen = offset.sqrMagnitude;
Debug.Log("distance from ball is " + sqrLen);
offsetMultiplier = sqrLen;
speed = speed + offsetMultiplier;
*/

float forwardBackward = Input.GetAxis("Vertical") * speed * Time.deltaTime;
float leftToRight = Input.GetAxis("Horizontal") * speed * Time.deltaTime;

transform.Translate(0.0f, 0.0f, forwardBackward);

transform.Translate(leftToRight, 0.0f, 0.0f);

transform.LookAt(ball);

}


The main idea here is to assign the ball as a game object and using "LookAt" to rotate your paddle toward the ball. From there, you can use the z position of the paddle to move closer and further away, and the x position to move side to side. Since the z position is always looking at the ball, the x movement will always be in a circle around the ball.

The one problem I had was when the paddle got very far away, the speed was relatively much slower than close up. I couldn't come up with a solution to that problem, but also not sure if you need that. My attempt is commented in the code snippet.

Goodluck and cheers!

• In your try to get the speed in relation to the distance you should clamp the max speed to avoid getting into surreal speeds.
– Nico
Feb 20, 2020 at 11:12
• Note that you can edit your existing answer to expand on it, rather than posting a separate answer. The only reason to post two answers is if you want to offer two different alternatives to be voted on separately. Feb 20, 2020 at 12:38