CameraFacingBillboard.cs

using UnityEngine;
using System.Collections;


/// <summary>
/// Класс для поворота канваса и объектов на камеру, вставляет внешний контейнер между собой и объектом
/// </summary>
public class CameraFacingBillboard : MonoBehaviour
{
    public Camera Camera;
    //added in-between GRP object to perform rotations on
    public GameObject Container;
    private Transform myParrent;

    void Awake(){
        if (GameObject.ReferenceEquals(Camera, null)) Debug.LogError("CameraFacingBillboard : Camera is null");
        myParrent = transform.parent;
        Container = new GameObject();
        Container.name = "GRP_" + transform.gameObject.name;
        Container.transform.position = transform.position;
        Container.transform.SetParent(myParrent);
        Container.transform.localScale = Vector3.one * (1 / myParrent.lossyScale.x);
        transform.SetParent(Container.transform);
        transform.localRotation = Quaternion.identity;
    }

    public float Height;
    private const float ChangeHeightKoeff = 2f;


    void LateUpdate()
    {
        Container.transform.LookAt(Container.transform.position + Camera.transform.localToWorldMatrix.MultiplyVector(Vector3.forward), Camera.transform.localToWorldMatrix.MultiplyVector(Vector3.up));
        Vector3 pos = Container.transform.localPosition;
        if (Mathf.Abs(pos.y - Height) > .01f)
        {
            pos = new Vector3(pos.x, pos.y + (pos.y < Height ? 1 : -1) * (Mathf.Min(Time.deltaTime * ChangeHeightKoeff, Mathf.Abs(pos.y - Height))), pos.z);
            Container.transform.localPosition = pos;
        }
    }
}