去掉obi，使用自写绳索

Assets/Obi/Scripts/Common/DataStructures/VInt4.cs

@@ -1,41 +0,0 @@
-using System;
-using System.Runtime.InteropServices;
-
-#if (OBI_MATHEMATICS)
-using Unity.Mathematics;
-#endif
-
-
-namespace Obi
-{
-    [Serializable]
-    [StructLayout(LayoutKind.Sequential)]
-    public struct VInt4
-    {
-        public int x;
-        public int y;
-        public int z;
-        public int w;
-
-        public VInt4(int x, int y, int z, int w)
-        {
-            this.x = x;
-            this.y = y;
-            this.z = z;
-            this.w = w;
-        }
-
-        public VInt4(int x)
-        {
-            this.x = x;
-            this.y = x;
-            this.z = x;
-            this.w = x;
-        }
-
-#if (OBI_MATHEMATICS)
-        public static implicit operator VInt4(int4 i) => new VInt4(i.x, i.y, i.z, i.w);
-        public static implicit operator int4(VInt4 i) => new int4(i.x, i.y, i.z, i.w);
-#endif
-    }
-}