scripting ropes with pin constraints & tethers

Code:
using UnityEngine;

using System.Collections;



namespace Obi {

    [RequireComponent(typeof(ObiRope))]

    [RequireComponent(typeof(ObiCatmullRomCurve))]

    [RequireComponent(typeof(ObiPinConstraints))]

    [RequireComponent(typeof(ObiDistanceConstraints))]

    [RequireComponent(typeof(ObiTetherConstraints))]



    public class ObiConnectorRope : MonoBehaviour {



        public ObiSolver solver;

        public ObiActor actor;

        

        public ObiRopeSection section;

        public Material material;

        

        public float ropeLength = 1.0f; // desired rope length

        public float uvYMult = 2.5f; // keep UVScale Y consistent across rope lengths

        

        public ObiCollider upperPinObject;

        public ObiCollider lowerPinObject;

        

        private Transform point1; // offset at top of object

        private Transform point2; // offset at bottom of object

        

        private ObiRope rope;

        private ObiCatmullRomCurve path;

        

        private ObiPinConstraints pinConstraints;

        private ObiPinConstraintBatch constraintsBatch;

        private ObiDistanceConstraints distanceConstraints;

    

        void Start () {

            

            actor.enabled = false;

            

            // move rope position to match upper pinned object

            transform.position = upperPinObject.transform.position;

            

            // Get all needed components and interconnect them:

            rope = GetComponent<ObiRope>();

            path = GetComponent<ObiCatmullRomCurve>();

            rope.Solver = solver;

            rope.ropePath = path;    

            rope.Section = section;

            GetComponent<MeshRenderer>().material = material;

            

            // use stretching scale to set approximate rope length & UVScale Y

            distanceConstraints = rope.GetComponent<ObiDistanceConstraints>();

            distanceConstraints.stretchingScale = (ropeLength * 0.14f) - 0.05f; // ad hoc formula

            rope.UVScale = new Vector2(1.0f, ropeLength * uvYMult);

            

            // register offsets

            point1 = upperPinObject.transform.Find("pinPointB").gameObject.transform;

            point2 = lowerPinObject.transform.Find("pinPointA").gameObject.transform;

            

            // Calculate rope start/end and direction in local space:

            Vector3 localStart = transform.InverseTransformPoint(upperPinObject.transform.position);

            Vector3 localEnd = transform.InverseTransformPoint(lowerPinObject.transform.position);

            Vector3 direction = (localEnd-localStart).normalized;

            // Add control points

            path.controlPoints.Add(localStart-direction);

            path.controlPoints.Add(localStart);

            path.controlPoints.Add(localEnd);

            path.controlPoints.Add(localEnd+direction);



            // Setup the simulation:

            StartCoroutine(Setup());

            

            // Wait for next FixedUpdate

            StartCoroutine(WaitOne());

            

            actor.enabled = true;

        }



        IEnumerator Setup(){

            

            // Generate particles and add them to solver:        

            yield return StartCoroutine(rope.GeneratePhysicRepresentationForMesh());

            

            rope.AddToSolver(null);

            

            // Generate tethers

            // Fix first particle:

            float tempMass = rope.invMasses[0];

            rope.invMasses[0] = 0;

            Oni.SetParticleInverseMasses(solver.OniSolver,new float[]{0},1,rope.particleIndices[0]);

            rope.GenerateTethers(ObiActor.TetherType.AnchorToFixed);

            // Unfix first particle:

            rope.invMasses[0] = tempMass;

            Oni.SetParticleInverseMasses(solver.OniSolver,new float[]{0},1,rope.particleIndices[0]);

            actor.PushDataToSolver(ParticleData.INV_MASSES); 

            

            // Set pin constraints    

            pinConstraints = rope.GetComponent<ObiPinConstraints> ();

            constraintsBatch = (ObiPinConstraintBatch)pinConstraints.GetBatches() [0];

            pinConstraints.RemoveFromSolver(null);    

            // Add top pin constraint

            constraintsBatch.AddConstraint(rope.particleIndices[rope.particleIndices[0]], upperPinObject.GetComponent<ObiCollider>(), point1.localPosition, 0f);

            // Add bottom pin constraint

            constraintsBatch.AddConstraint(rope.particleIndices[rope.UsedParticles-1], lowerPinObject.GetComponent<ObiCollider>(), point2.localPosition, 0f);



            pinConstraints.AddToSolver(null);

            

            pinConstraints.PushDataToSolver();

        }    

        

        IEnumerator WaitOne(){

            yield return new WaitForFixedUpdate();

        }    

    }

}