How to make the camera follow and face a rolling object?

Question

I'm new to Unity, and trying to make the camera follow a rolling ball and rotate with it on the y axis so that the camera stays behind the ball and always faces in the ball's direction of motion. This is my current script:

 public class CameraMover : MonoBehaviour
 {
     public Transform tf;
     public Transform ballTransform;
     public Vector3 distanceBetweenBallAndCam;
     float yRotation;
 
     // Start is called before the first frame update
     void Start()
     {
         distanceBetweenBallAndCam = tf.position - ballTransform.position;
     }
 
     // Update is called once per frame
     void Update()
     {
         tf.position = ballTransform.position + distanceBetweenBallAndCam;
         yRotation = ballTransform.eulerAngles.y;
         tf.eulerAngles = new Vector3(tf.eulerAngles.x, yRotation, tf.eulerAngles.z);
     }
 }

As it is, the camera follows the ball fine, but encounters some problems on the rotation. When the ball is rolling straight down a ramp and is only rotating on the x or z axis, the camera rotates 180 degrees every half rotation of the ball. When it begins rotating on the y axis, the same problem continues to apply, with the additional issue of the camera not properly moving behind the ball. Is there a way to easily fix these problems or do I need to restart my script from scratch? Thanks in advance.

Answer 1

Cinemachine is a unity package that allows you to make a following camera with a smooth effect. You can find lot of videos about it and documentation here.

I don't know exactly your project technical aspect but if you use rigid body, you can't control the rotation of your Y-axis even with freeze it. Otherwise, you can use your velocity to know is wich direction your ball go and control your camera :

 public class CameraMover : MonoBehaviour
 {
     public Transform tf;
     public Transform ballTransform;
     public Rigidbody rgBall;
  
     // Start is called before the first frame update
     void Start()
     {
         rgBall = ballTransform.GetComponent<Rigidbody>();
     }
  
     // Update is called once per frame
     void Update()
     {
         // Dot product of two normalized vector is equals to cos of theire angle.
         float yRotation = -Mathf.Acos(Vector3.Dot(rgBall.velocity.normalized, Vector3.right)) * Mathf.Rad2Deg;
         tf.eulerAngles = new Vector3(0, yRotation, 0);
     }
 }

To rotate around the ball I use an intermediate object with your script inside and camera in child

alt text

Answer 2

Answer by ssamii · Sep 19, 2021 at 02:31 PM

you can use this script:

 using UnityEngine;
 using System.Collections;
 
 public class CompleteCameraController : MonoBehaviour
 {
 
     public GameObject player;        //Public variable to store a reference to the player game object
 
 
     private Vector3 offset;            //Private variable to store the offset distance between the player and camera
 
     // Use this for initialization
     void Start()
     {
         //Calculate and store the offset value by getting the distance between the player's position and camera's position.
         offset = transform.position - player.transform.position;
     }
 
     // LateUpdate is called after Update each frame
     void LateUpdate()
     {
         // Set the position of the camera's transform to be the same as the player's, but offset by the calculated offset distance.
         transform.position = player.transform.position + offset;
     }                                                                         
 }

Add comment · Show 3 · Share

Renardjojo · Sep 19, 2021 at 02:37 PM 0

Share

I think he want not only translation but also rotates around it sphere depending on its direction (If I understand properly)

ssamii · Sep 19, 2021 at 02:42 PM 0

Share

he want the camera to stay behind the ball and this is simple script for that

Spartan299 ssamii · Sep 19, 2021 at 02:45 PM 0

Share

It’s in the title: how to make the camera follow and face a moving object

How to make the camera follow and face a rolling object?

2 Replies

Your answer

Follow this Question

Related Questions