绳子优化

Assets/Scenes/SampleScene.unity

@@ -404,7 +404,7 @@ BoxCollider:
   m_ProvidesContacts: 0
   m_Enabled: 1
   serializedVersion: 3
-  m_Size: {x: 10, y: 2, z: 10}
+  m_Size: {x: 10, y: 1, z: 10}
   m_Center: {x: 0, y: 0, z: 0}
 --- !u!23 &306060541
 MeshRenderer:
@@ -468,8 +468,8 @@ Transform:
   m_GameObject: {fileID: 306060539}
   serializedVersion: 2
   m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
-  m_LocalPosition: {x: 0, y: -100, z: 10}
+  m_LocalPosition: {x: 0, y: -3, z: 10}
-  m_LocalScale: {x: 10, y: 2, z: 10}
+  m_LocalScale: {x: 14.43, y: 2, z: 16.04}
   m_ConstrainProportionsScale: 0
   m_Children: []
   m_Father: {fileID: 0}
@@ -934,9 +934,9 @@ MonoBehaviour:
   m_EditorClassIdentifier: 
   mouseOffset: 10
   nodeDistance: 0.1
-  nodeColliderRadius: 0.2
+  nodeColliderRadius: 0.3
   gravityStrength: 1.962
-  totalLength: 10
+  totalLength: 6
   velocityDampen: 0.95
   stiffness: 0.99
   iterateCollisionsEvery: 1

Assets/Scripts/Rope.cs

@@ -11,7 +11,7 @@ public class Rope : MonoBehaviour
 
     [SerializeField] float nodeColliderRadius = 0.2f;
     [SerializeField] float gravityStrength = 2;
-    [SerializeField] float totalLength = 10f; // 新增总长度参数
+    [SerializeField] float totalLength = 10f;
     [SerializeField, Range(0, 1)] float velocityDampen = 0.95f;
     [SerializeField, Range(0, 0.99f)] float stiffness = 0.8f;
     [SerializeField, Range(1, 10)] int iterateCollisionsEvery = 1;
@@ -36,25 +36,11 @@ public class Rope : MonoBehaviour
     LineRenderer lineRenderer;
     GameObject nodeTester;
     SphereCollider nodeCollider;
-    int totalNodes; // 现在由代码计算
+    int totalNodes;
+    float lastTotalLength; // 用于检测长度变化
 
     void Awake()
     {
-        // 计算节点数量
-        totalNodes = Mathf.FloorToInt(totalLength / nodeDistance) + 1;
-        float remainingLength = totalLength % nodeDistance;
-
-        // 如果剩余长度大于0，增加一个节点
-        if (remainingLength > 0 && totalLength > nodeDistance)
-        {
-            totalNodes++;
-        }
-
-        // 初始化数组
-        currentNodePositions = new Vector3[totalNodes];
-        previousNodePositions = new Vector3[totalNodes];
-        colliderHitBuffer = new Collider[colliderBufferSize];
-
         // 获取组件引用
         lineRenderer = GetComponent<LineRenderer>();
         cam = Camera.main;
@@ -66,25 +52,59 @@ public class Rope : MonoBehaviour
         nodeCollider = nodeTester.AddComponent<SphereCollider>();
         nodeCollider.radius = nodeColliderRadius;
 
+        // 初始化长度跟踪
+        lastTotalLength = totalLength;
+        InitializeRope();
+    }
+
+    void InitializeRope()
+    {
+        // 计算节点数量
+        totalNodes = Mathf.FloorToInt(totalLength / nodeDistance) + 1;
+        float remainingLength = totalLength % nodeDistance;
+        
+        // 如果剩余长度大于0，增加一个节点
+        if (remainingLength > 0 && totalLength > nodeDistance)
+        {
+            totalNodes++;
+        }
+
+        // 初始化或调整数组大小
+        System.Array.Resize(ref currentNodePositions, totalNodes);
+        System.Array.Resize(ref previousNodePositions, totalNodes);
+        colliderHitBuffer = new Collider[colliderBufferSize];
+
         // 初始化节点位置
         Vector3 startPos = transform.position;
         for (int i = 0; i < totalNodes; i++)
         {
             // 如果是最后一个节点且有剩余长度，使用剩余长度
             float distance = (i == totalNodes - 1 && remainingLength > 0) ? remainingLength : nodeDistance;
-
+            
-            currentNodePositions[i] = startPos;
+            // 如果数组已有数据，保持现有位置，否则初始化新位置
-            previousNodePositions[i] = startPos;
+            if (currentNodePositions[i] == null)
+            {
+                currentNodePositions[i] = startPos;
+                previousNodePositions[i] = startPos;
+            }
             startPos.y -= distance;
         }
 
         // 设置线渲染器
         lineRenderer.startWidth = ropeWidth;
         lineRenderer.endWidth = ropeWidth;
+        lineRenderer.positionCount = totalNodes;
     }
 
     void Update()
     {
+        // 检查长度是否变化
+        if (!Mathf.Approximately(totalLength, lastTotalLength))
+        {
+            AdjustRopeLength();
+            lastTotalLength = totalLength;
+        }
+
         // 处理鼠标输入
         if (Input.GetMouseButtonDown(0))
         {
@@ -111,6 +131,36 @@ public class Rope : MonoBehaviour
         DrawRope();
     }
 
+    void AdjustRopeLength()
+    {
+        // 保存旧位置
+        Vector3[] oldPositions = (Vector3[])currentNodePositions.Clone();
+        Vector3[] oldPrevPositions = (Vector3[])previousNodePositions.Clone();
+
+        // 重新初始化绳索
+        InitializeRope();
+
+        // 尽可能保留旧位置数据
+        int copyLength = Mathf.Min(oldPositions.Length, currentNodePositions.Length);
+        System.Array.Copy(oldPositions, currentNodePositions, copyLength);
+        System.Array.Copy(oldPrevPositions, previousNodePositions, copyLength);
+
+        // 如果长度增加，初始化新增节点的位置
+        if (currentNodePositions.Length > oldPositions.Length)
+        {
+            Vector3 lastPos = oldPositions[oldPositions.Length - 1];
+            for (int i = oldPositions.Length; i < currentNodePositions.Length; i++)
+            {
+                float distance = (i == currentNodePositions.Length - 1 && (totalLength % nodeDistance) > 0) ? 
+                                (totalLength % nodeDistance) : nodeDistance;
+                
+                lastPos.y -= distance;
+                currentNodePositions[i] = lastPos;
+                previousNodePositions[i] = lastPos;
+            }
+        }
+    }
+
     void FixedUpdate()
     {
         Simulate();
@@ -164,10 +214,9 @@ public class Rope : MonoBehaviour
             Vector3 diff = node1 - node2;
 
             // 计算期望的距离 - 如果是最后一个段且有剩余长度，使用剩余长度
-            float desiredDistance = (i == nodeCountMinusOne - 1 && (totalLength % nodeDistance) > 0)
+            float desiredDistance = (i == nodeCountMinusOne - 1 && (totalLength % nodeDistance) > 0) ? 
-                ? (totalLength % nodeDistance)
+                                   (totalLength % nodeDistance) : nodeDistance;
-                : nodeDistance;
+            
-
             float sqrDesiredDistance = desiredDistance * desiredDistance;
             float sqrDistance = diff.x * diff.x + diff.y * diff.y + diff.z * diff.z;
 
@@ -176,7 +225,7 @@ public class Rope : MonoBehaviour
             {
                 float distance = Mathf.Sqrt(sqrDistance);
                 float difference = desiredDistance - distance;
-                Vector3 direction = diff / distance; // 比 normalized 更快
+                Vector3 direction = diff / distance;
 
                 Vector3 adjustment = direction * (difference * halfStiffness);
 
@@ -188,13 +237,13 @@ public class Rope : MonoBehaviour
 
     void AdjustCollisions()
     {
-        for (int i = 1; i < totalNodes; i += 2) // 跳过更多节点减少计算
+        for (int i = 1; i < totalNodes; i += 2)
         {
             int hits = Physics.OverlapSphereNonAlloc(
                 currentNodePositions[i],
                 nodeColliderRadius,
                 colliderHitBuffer,
-                ~(1 << 8)); // 忽略特定层
+                ~(1 << 8));
 
             for (int n = 0; n < hits; n++)
             {
@@ -216,7 +265,6 @@ public class Rope : MonoBehaviour
 
     void DrawRope()
     {
-        // 直接使用currentNodePositions数组避免额外拷贝
         lineRenderer.positionCount = totalNodes;
         lineRenderer.SetPositions(currentNodePositions);
     }