I tried to assume to resolve all your question, please see the code below.
Time.deltaTime is not needed, since your code (and my) using the Time.time to calculate each time the position of the object.
I also would recommend (if possible) to not put all in on script, but give each object a swing script and also try to not use the CoRoutine. But to answer your question I show you how to do it.
I have created an internal class, to store in the "Init" the targeted gameobjects and their startPosition in a list. Later you can simply loop throu this list and always have the start position.
You need an endless loop in the "Osciallate" routine and need to wait each turn. In your example you put the Wait on the wrong place, so it waits after moving each object and stops after the first run throu all of this objects.
Here the code:
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class OscilateObs : MonoBehaviour {
// internal class where all gameobjects and their startposition will be saved
internal class OscGameObjects
{
public GameObject gameObject;
public Vector3 startPosition;
}
// Here the information of all gameObjects stored in a list
private List<OscGameObjects> objectList;
public float updateSpeed = 0.05f;
public float oscScalar = 2f;
public enum OscillationFunction {
Sine = 1
}
void Start () {
// First, the gameobjects have to saved to our internal List
InitializeOscGameObjects();
// Start the Corotine
StartCoroutine(Oscillate(OscillationFunction.Sine, oscScalar));
}
private void InitializeOscGameObjects()
{
var objects = GameObject.FindGameObjectsWithTag("MovingObs2");
objectList = new List<OscGameObjects>();
foreach (var o in objects)
{
var oscObject = new OscGameObjects();
oscObject.gameObject = o;
oscObject.startPosition = o.transform.position;
objectList.Add(oscObject);
}
}
public IEnumerator Oscillate(OscillationFunction method, float scalar)
{
// Loop forever
while(true)
{
foreach (var element in objectList)
{
var currentPosition = element.gameObject.transform.position;
currentPosition.x = element.startPosition.x + Mathf.Cos(Time.time) * scalar;
element.gameObject.transform.position = currentPosition;
}
yield return new WaitForSeconds(updateSpeed);
}
}
}
EDIT:
I forgot to meantion:
1) I would recommend to use "Animation" Component for the movement and not using C# at all, so you can change the behaviour if needed and you are more flexible.
2) I would also recommend if possible to make a parent "GameObject" and moving only this and put the "MovingOb2" simply as child objects.
EDIT2:
Adding a delay increment for each object, so they not running syncron:
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class OscilateObs : MonoBehaviour {
// internal class where all gameobjects and their startposition will be saved
internal class OscGameObjects
{
public GameObject gameObject;
public Vector3 startPosition;
public float waitCount;
}
// Here the information of all gameObjects stored in a list
private List<OscGameObjects> objectList;
public float updateSpeed = 0.05f;
public float oscScalar = 2f;
public float waitIncrementTime = 0.01f;
public enum OscillationFunction {
Sine = 1
}
void Start () {
// First, the gameobjects have to saved to our internal List
InitializeOscGameObjects();
// Start the Corotine
StartCoroutine(Oscillate(OscillationFunction.Sine, oscScalar));
}
private void InitializeOscGameObjects()
{
var objects = GameObject.FindGameObjectsWithTag("MovingObs2");
objectList = new List<OscGameObjects>();
float i = 0;
foreach (var o in objects)
{
i += waitIncrementTime;
var oscObject = new OscGameObjects();
oscObject.gameObject = o;
oscObject.startPosition = o.transform.position;
oscObject.waitCount = i;
objectList.Add(oscObject);
}
}
public IEnumerator Oscillate(OscillationFunction method, float scalar)
{
// Loop forever
while(true)
{
foreach (var element in objectList)
{
var currentPosition = element.gameObject.transform.position;
currentPosition.x = element.startPosition.x + Mathf.Cos(Time.time + element.waitCount) * scalar;
element.gameObject.transform.position = currentPosition;
}
yield return new WaitForSeconds(updateSpeed);
}
}
}