去掉obi，使用自写绳索

Assets/Obi/Scripts/Common/Utils/ObiParticleAttachment.cs

@@ -1,70 +0,0 @@
-using System;
-using UnityEngine;
-
-namespace Obi
-{
-    [AddComponentMenu("Physics/Obi/Obi Particle Attachment", 820)]
-    [RequireComponent(typeof(ObiActor))]
-    [ExecuteInEditMode]
-    public class ObiParticleAttachment : MonoBehaviour
-    {
-        public enum AttachmentType
-        {
-            Static,
-            Dynamic
-        }
-
-        [SerializeField] [HideInInspector] private ObiActor m_Actor;
-        [SerializeField] [HideInInspector] private Transform m_Target;
-
-        [SerializeField] [HideInInspector] private ObiParticleGroup m_ParticleGroup;
-        [SerializeField] [HideInInspector] private AttachmentType m_AttachmentType = AttachmentType.Static;
-        [SerializeField] [HideInInspector] private bool m_ConstrainOrientation = false;
-        [SerializeField] [HideInInspector] private bool m_Projection = false;
-        [SerializeField] [HideInInspector] private float m_Compliance = 0;
-
-        // private variables are serialized during script reloading, to keep their value. Must mark them explicitly as non-serialized.
-        [NonSerialized] private ObiPinConstraintsBatch pinBatch;
-        [NonSerialized] private ObiColliderBase attachedCollider;
-        [NonSerialized] private int attachedColliderHandleIndex;
-
-        [NonSerialized] private int[] m_SolverIndices;
-        [NonSerialized] private Vector3[] m_PositionOffsets = null;
-        [NonSerialized] private Quaternion[] m_OrientationOffsets = null;
-
-        /// <summary>  
-        /// The actor this attachment is added to.
-        /// </summary> 
-        public ObiActor actor
-        {
-            get { return m_Actor; }
-        }
-
-        /// <summary>  
-        /// The target transform that the <see cref="particleGroup"/> should be attached to.
-        /// </summary> 
-        public Transform target
-        {
-            get { return m_Target; }
-            set
-            {
-                if (value != m_Target)
-                {
-                    m_Target = value;
-                    Bind();
-                }
-            }
-        }
-
-        /// <summary>  
-        /// The particle group that should be attached to the <see cref="target"/>.
-        /// </summary> 
-        public ObiParticleGroup particleGroup
-        {
-            get
-            {
-                return m_ParticleGroup;
-            }
-
-            set
-            {