Help Generated rope with pin constraints

Code:
using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using Obi;



/**

 * Sample component that shows how to use Obi Rope to create a grappling hook for a 2.5D game.

 * 95% of the code is the grappling hook logic (user input, scene raycasting, launching, attaching the hook, etc) and parameter setup,

 * to show how to use Obi completely at runtime. This might not be practical for real-world scenarios,

 * but illustrates how to do it.

 *

 * Note that the choice of using actual rope simulation for grapple dynamics is debatable. Usually

 * a simple spring works better both in terms of performance and controllability. 

 *

 * If complex interaction is required with the scene, a purely geometry-based approach (ala Worms ninja rope) can

 * be the right choice under certain circumstances.

 */

public class Sling : MonoBehaviour

{



    public ObiSolver solver;

    public ObiCollider hook;

    public float hookExtendRetractSpeed = 2;

    public Material material;

    public ObiRopeSection section;



    private ObiRope rope;

    private ObiRopeBlueprint blueprint;

    private ObiRopeExtrudedRenderer ropeRenderer;



    private ObiRopeCursor cursor;



    private RaycastHit hookAttachment;

    private bool attached = false;



    void Awake()

    {



        // Create both the rope and the solver:    

        rope = gameObject.AddComponent<ObiRope>();

        ropeRenderer = gameObject.AddComponent<ObiRopeExtrudedRenderer>();

        ropeRenderer.section = section;

        ropeRenderer.uvScale = new Vector2(1, 5);

        ropeRenderer.normalizeV = false;

        ropeRenderer.uvAnchor = 0;

        rope.GetComponent<MeshRenderer>().material = material;



        // Setup a blueprint for the rope:

        blueprint = ScriptableObject.CreateInstance<ObiRopeBlueprint>();

        blueprint.resolution = 1.0f;

        blueprint.thickness = 0.1f;



        // Tweak rope parameters:

        rope.maxBending = 0.02f;



        // Add a cursor to be able to change rope length:

        cursor = rope.gameObject.AddComponent<ObiRopeCursor>();

        cursor.cursorMu = 0;

        cursor.direction = true;

    }



    private void OnDestroy()

    {

        DestroyImmediate(blueprint);

    }



    /**

     * Raycast against the scene to see if we can attach the hook to something.

     */

    private void LaunchHook()

    {



        // Get the mouse position in the scene, in the same XY plane as this object:

        Vector3 mouse = Input.mousePosition;

        mouse.z = 100000.0f;

        Vector3 mouseInScene = Camera.main.ScreenToWorldPoint(mouse);



        // Get a ray from the camera to the mouse:

        Ray ray = new Ray(Camera.main.transform.position, mouseInScene);





        // Raycast to see what we hit:

        if (Physics.Raycast(ray, out hookAttachment))

        {

            // We actually hit something, so attach the hook!

            StartCoroutine(AttachHook());

        }



    }



    private IEnumerator AttachHook()

    {

        yield return 0;

        Vector3 localHit = rope.transform.InverseTransformPoint(hookAttachment.point);



        // Procedurally generate the rope path (a simple straight line):

        blueprint.path.Clear();

        blueprint.path.AddControlPoint(hook.transform.localPosition + Vector3.down * 0.6f, Vector3.up, Vector3.down, Vector3.up, 0.1f, 0.1f, 1, 1, Color.white, "Sling hook");

        blueprint.path.AddControlPoint(localHit, Vector3.up, Vector3.down, Vector3.up, 0.1f, 0.1f, 1, 1, Color.white, "Sling load");

        blueprint.path.FlushEvents();



        // Generate the particle representation of the rope (wait until it has finished):

        yield return blueprint.Generate();



        // Pin both ends of the rope (this enables two-way interaction between character and rope):

        var pinConstraints = blueprint.GetConstraintsByType(Oni.ConstraintType.Pin) as ObiConstraints<ObiPinConstraintsBatch>;

        var batch = pinConstraints.batches[0];

        batch.AddConstraint(0, hook, transform.localPosition + Vector3.down * 0.6f, Quaternion.identity);

        //batch.AddConstraint(blueprint.activeParticleCount - 1, hookAttachment.collider.GetComponent<ObiColliderBase>(), hookAttachment.collider.transform.InverseTransformPoint(hookAttachment.point), Quaternion.identity);

        batch.AddConstraint(blueprint.activeParticleCount - 1, hookAttachment.collider.GetComponent<ObiCollider>(), hookAttachment.transform.InverseTransformPoint(hookAttachment.point), Quaternion.identity);

        batch.activeConstraintCount = 2;



        // Set the blueprint (this adds particles/constraints to the solver and starts simulating them).

        rope.ropeBlueprint = blueprint;

        rope.GetComponent<MeshRenderer>().enabled = true;

    }



    private void DetachHook()

    {

        // Set the rope blueprint to null (automatically removes the previous blueprint from the solver, if any).

        rope.ropeBlueprint = null;

        rope.GetComponent<MeshRenderer>().enabled = false;

    }





    void Update()

    {



        if (Input.GetMouseButtonDown(0))

        {

            if (!rope.isLoaded)

                LaunchHook();

            else

                DetachHook();

        }



        if (rope.isLoaded)

        {

            if (Input.GetKey(KeyCode.W))

            {

                cursor.ChangeLength(rope.restLength - hookExtendRetractSpeed * Time.deltaTime);

            }

            if (Input.GetKey(KeyCode.S))

            {

                cursor.ChangeLength(rope.restLength + hookExtendRetractSpeed * Time.deltaTime);

            }

        }

    }

}