【Unity】衛星軌道（円周）

Satellite.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public enum AROUNDLR
{
    LEFT,
    RIGHT
}

public class Satellite : MonoBehaviour
{
    [SerializeField]
    float speed;

    [SerializeField]
    float radius = 5.0f;

    [SerializeField]
    AROUNDLR aroundLR = AROUNDLR.LEFT;
    private int LR;

    [SerializeField]
    GameObject center;

    void Start()
    {
        LR = (int)aroundLR * 2 - 1;
    }

    private void Update()
    {
        //update position
        var dt = Time.deltaTime;
        transform.position += transform.forward * dt * speed;

        //update rotation
        transform.rotation = GetRotToCenter();
    }

    Quaternion GetRotToCenter()
    {
        Vector3 toCenter = center.transform.position - transform.position;
        Vector3 toMe = transform.position - center.transform.position;

        Vector3 projectionToMe = Vector3.ProjectOnPlane(toMe, center.transform.up);
        Vector3 radVec = projectionToMe.normalized * radius;
        Vector3 toRad = toCenter + radVec;
        Vector3 vertToRad = Vector3.Cross(LR * center.transform.up, projectionToMe);

        return Quaternion.LookRotation(toRad + vertToRad);
    }
}