Help Rope extension, vibration and collision

[0hsyn1]

No, "particleIndex" is as the comment in the code points out. "simplexStart" is the first entry in the simplices array, and "simplexSize" the size of the simplex. So when a simplex collides, you get a start and a size. The indices of the colliding particles are stored in solver.simplices[simplexStart] to solver.simplices[simplexStart+simplexSize].


If none of your ropes use surface-based collisions, all simplices in the solver have size 1 and it's not needed to iterate over all particles in each simplex. You can just do what you were doing before:

Code:

int particleIndex = solver.simplices[contact.bodyA];

I just tried the script and it works perfectly for me. I'm attaching the version of the script that I used to perform the test, maybe you can spot any difference with what you're doing?

Code:

using UnityEngine;
using Obi;

public class RopeContactNormalized : MonoBehaviour
{
    public ObiRope rope;

    // Start is called before the first frame update
    void Start()
    {
        rope.solver.OnCollision += OnRopeContactEnter;
    }

    public void OnRopeContactEnter(ObiSolver solver, ObiNativeContactList contacts)
    {
        var world = ObiColliderWorld.GetInstance();
        float normalizedCoordinate = -1;

        foreach (var contact in contacts)
        {
            if (contact.distance > 0.001f) continue;

            int particleIndex = solver.simplices[contact.bodyA];
            var col = world.colliderHandles[contact.bodyB].owner;

            if (rope != null)
            {
                var elements = rope.elements;

                int elementIndex = -1;

                for (int i = 0; i < elements.Count; ++i)
                {
                    var element = elements[i];
                    if (element.particle1 == particleIndex || element.particle2 == particleIndex)
                    {
                        elementIndex = i;
                        break;
                    }
                }

                if (elementIndex != -1)
                {
                    normalizedCoordinate = (float)elementIndex / elements.Count;
                    Debug.Log("Normalized rope position: " + normalizedCoordinate);
                    break;

                }
                else
                {
                    Debug.LogWarning("Element not found for particle " + particleIndex);
                }
            }
            else
            {
                Debug.LogWarning("Rope reference is missing!");
            }
        }

        if (normalizedCoordinate >= 0)
        {
            var section = rope.GetComponent<ObiPathSmoother>().GetSectionAt(normalizedCoordinate);
            Debug.DrawRay(section.position, section.normal, Color.red);
        }
    }
}

ObiNativeContactList  I don't have the definition, it gives a warning.
 I'm listening to the events of the script ObiContactEventDispatcher