Multi-touch dragrigidbody script?

Questions & Answers
1

My game depends on dragging two rigid bodies attached to spring joints at once, but the standard dragrigidbody.js doesn't support it. How can I add this functionality?

2

Here is the one I wrote from this [forum post][1]

using UnityEngine;
using System.Collections;
 
public class MultiDragRigidbody2D : MonoBehaviour
{
    public int maxTouch = 2;
    [Range(0,31)]
    public int layerMask = 0;
    public float distance = 0.2f;
    public float dampingRatio = 1;
    public float frequency = 1.8f;
    public float linearDrag = 1.0f;
    public float angularDrag = 5.0f;
    public bool centerOfMass = false;
    private SpringJoint2D[] springJoints;
 
    void Start ()
    {
        springJoints = new SpringJoint2D[maxTouch];
 
        for (int i = 0; i < maxTouch; i++) {
            GameObject go = new GameObject ("Dragger" + (i + 1));
            go.transform.parent = this.transform;
       
            Rigidbody2D body = go.AddComponent ("Rigidbody2D") as Rigidbody2D;
            springJoints  *= go.AddComponent ("SpringJoint2D") as SpringJoint2D;*

body.isKinematic = true;
}
}

void Update ()
{
foreach (Touch touch in Input.touches) {
int Id = touch.fingerId;

if (Id < maxTouch && touch.phase == TouchPhase.Began) {
Camera mainCamera = FindCamera ();
Ray ray = mainCamera.ScreenPointToRay (touch.position);
RaycastHit2D hit = Physics2D.GetRayIntersection (ray, Mathf.Infinity, 1 << layerMask);

if (hit.rigidbody != null && hit.rigidbody.isKinematic == false) {
springJoints [Id].transform.position = hit.point;
springJoints [Id].connectedBody = hit.rigidbody;

if (centerOfMass)
springJoints [Id].connectedAnchor = hit.rigidbody.centerOfMass;
else
springJoints [Id].connectedAnchor = hit.transform.InverseTransformPoint (hit.point);

float length = (hit.transform.position - mainCamera.transform.position).magnitude;
StartCoroutine (DragObject (Id, length));
}
}
}
}

IEnumerator DragObject (int Id, float length)
{
float oldDrag = springJoints [Id].connectedBody.drag;
float oldAngularDrag = springJoints [Id].connectedBody.angularDrag;
springJoints [Id].distance = distance;
springJoints [Id].dampingRatio = dampingRatio;
springJoints [Id].frequency = frequency;
springJoints [Id].connectedBody.drag = linearDrag;
springJoints [Id].connectedBody.angularDrag = angularDrag;
Camera mainCamera = FindCamera ();

while (true) {
bool touchExists = false;
foreach (Touch touch in Input.touches) {
if (touch.fingerId == Id) {
touchExists = true;
Ray ray = mainCamera.ScreenPointToRay (touch.position);
springJoints [Id].transform.position = ray.GetPoint (length);
}
}
if (touchExists)
yield return null;
else
break;
}

if (springJoints [Id].connectedBody) {
springJoints [Id].connectedBody.drag = oldDrag;
springJoints [Id].connectedBody.angularDrag = oldAngularDrag;
springJoints [Id].connectedBody = null;
}
}

Camera FindCamera ()
{
if (camera)
return camera;
else
return Camera.main;
}
}
[1]: http://forum.unity3d.com/threads/rigidbody2d-dragable-script.212168/#post-1664297