diff --git a/src/BallanceStalker.csproj b/src/BallanceStalker.csproj
index 8bb664b..4df8686 100644
--- a/src/BallanceStalker.csproj
+++ b/src/BallanceStalker.csproj
@@ -3,6 +3,8 @@
     <TargetFramework>net472</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="Brigadier.NET" Version="1.2.13" />
     <PackageReference Include="Google.Protobuf" Version="3.21.1" />
+    <PackageReference Include="zlib.net" Version="1.0.4" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/scripts/cores/managers/RecManager.cs b/src/scripts/cores/managers/RecManager.cs
index b55ba48..d973540 100644
--- a/src/scripts/cores/managers/RecManager.cs
+++ b/src/scripts/cores/managers/RecManager.cs
@@ -1,4 +1,5 @@
-using System;
+using BallanceStalker.Cores.Utils;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -6,5 +7,23 @@ using System.Threading.Tasks;
 
 namespace BallanceStalker.Cores.Managers {
     public class RecManager {
+
+        public event Action<Guid, IRec> RecAdded;
+        public event Action<Guid, IRec> RecRemoved;
+
+        private Dictionary<Guid, IRec> mRecDict = new Dictionary<Guid, IRec>();
+
+        public Guid AddSpiritTrailRec(string rec_folder) {
+
+        }
+
+        public void RemoveRec(Guid uuid) {
+
+        }
+
+        public void Tick(float delta) {
+
+        }
+
     }
 }
diff --git a/src/scripts/cores/rec/SpiritTrailRec.cs b/src/scripts/cores/rec/SpiritTrailRec.cs
index c8026a8..34d3d07 100644
--- a/src/scripts/cores/rec/SpiritTrailRec.cs
+++ b/src/scripts/cores/rec/SpiritTrailRec.cs
@@ -5,51 +5,217 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Threading;
+using System.IO;
+using System.IO.Compression;
+using zlib;
+using System.Runtime.InteropServices;
+using System.Numerics;
 
 namespace BallanceStalker.Cores.Rec {
+
+    public struct SpiritTrailTrafo {
+        public int Frame;
+        public VxBallType TrafoType;
+    }
+
+    public enum SpiritTrailRecType {
+        HS,
+        SR
+    }
+
     public class SpiritTrailRec : Utils.IRec {
-        public SpiritTrailRec(string rec_folder) {
+
+        static readonly float REC_DELTA = 1f / 8f;
+
+        public SpiritTrailRec(string rec_folder, SpiritTrailRecType t) {
             mIsReady = mIsPlaying = false;
-            Task.Run(() => {
-                // load data
 
+            mFileFolder = rec_folder;
+            mFileType = t;
+            mFileCursor = 1;
 
-                lock (mStatusLock) {
-                    mIsReady = true;
-                }
-            });
+            mRecStateCursor = mRecTrafoCursor = 0;
+            mRecRemainDelta = 0f;
         }
 
         public event Action<long, string> RecRegisterBall;
-        public event Action RecPlaying;
-        public event Action RecPaused;
         public event Action<long> RecUnregisterBall;
+        public event Action<RecBallStateReport> RecNewBallState;
+        public event Action<List<RecBallStateReport>> RecNewBallStates;
 
         object mStatusLock;
         bool mIsReady, mIsPlaying;
 
+        string mFileFolder;
+        SpiritTrailRecType mFileType;
+        int mFileCursor;
+
+        int mRecHSScore;
+        float mRecSRScore;
+        VxBallState[] mRecStates;
+        SpiritTrailTrafo[] mRecTrafos;
+
+        int mRecStateCursor, mRecTrafoCursor;
+        float mRecRemainDelta;
+
+        private void LoadData() {
+            // load data
+            bool success = true;
+            try {
+                // check exist
+                var filename = System.IO.Path.Combine(mFileFolder, mFileType == SpiritTrailRecType.HS ? $"hs{mFileCursor}.rec" : $"sr{mFileCursor}.rec");
+                if (!System.IO.File.Exists(filename))
+                    throw new ArgumentOutOfRangeException("spirit trail index overflow.");
+
+                // analyse file
+                using (var ms = new MemoryStream()) {
+                    // decompress
+                    int decomp;
+                    using (var zo = new zlib.ZOutputStream(ms, 9)) {
+                        using (var fs = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read)) {
+                            // read header
+                            var data = new byte[4];
+                            fs.Read(data, 0, 4);
+                            decomp = BitConverter.ToInt32(data, 0);
+
+                            fs.CopyTo(zo);
+                        }
+                        zo.finish();
+                    }
+
+                    // check size
+                    if (ms.Length != decomp)
+                        throw new ArgumentOutOfRangeException("expected stream size if not matched real size in zlib decompression.");
+
+                    // read data
+                    using (var br = new BinaryReader(ms, Encoding.ASCII, true)) {
+                        // read basic data
+                        mRecHSScore = br.ReadInt32();
+                        mRecSRScore = br.ReadSingle();
+                        int states_count = br.ReadInt32();
+                        int trafo_count = br.ReadInt32();
+
+                        // read states data
+                        mRecStates = new VxBallState[states_count];
+                        byte[] buffer = br.ReadBytes(states_count * 4 * (3 + 4));
+                        Buffer.BlockCopy(buffer, 0, mRecStates, 0, states_count);
+                        //for (int i = 0; i < states_count; ++i) {
+                        //    mRecStates[i].Pos.X = br.ReadSingle();
+                        //    mRecStates[i].Pos.Y = br.ReadSingle();
+                        //    mRecStates[i].Pos.Z = br.ReadSingle();
+                        //    mRecStates[i].Quat.X = br.ReadSingle();
+                        //    mRecStates[i].Quat.Y = br.ReadSingle();
+                        //    mRecStates[i].Quat.Z = br.ReadSingle();
+                        //    mRecStates[i].Quat.W = br.ReadSingle();
+                        //}
+
+                        // read trafo data
+                        mRecTrafos = new SpiritTrailTrafo[trafo_count];
+                        buffer = br.ReadBytes(states_count * 8);
+                        Buffer.BlockCopy(buffer, 0, mRecTrafos, 0, trafo_count);
+                        //for (int i = 0; i < trafo_count; ++i) {
+                        //    mRecTrafo[i].Frame = br.ReadInt32();
+                        //    mRecTrafo[i].TrafoType = (BallType)br.ReadInt32();
+                        //}
+                    }
+                }
+
+                // increase sector
+                mFileCursor++;
+            } catch {
+                success = false;
+            }
+
+            // feedback status
+            lock (mStatusLock) {
+                mIsReady = success;
+            }
+        }
+
+
+        public void Startup() {
+            RecRegisterBall?.Invoke(0, Path.GetFileName(mFileFolder));
+
+            Task.Run(() => {
+                LoadData();
+            });
+        }
+
+        public void Shutdown() {
+            RecUnregisterBall?.Invoke(0);
+        }
+
         public void Pause() {
             lock (mStatusLock) {
                 mIsPlaying = false;
             }
+            //RecPaused?.Invoke();
         }
 
         public void Play() {
             lock (mStatusLock) {
                 mIsPlaying = true;
             }
+            //RecPlaying?.Invoke();
         }
 
         public void Seek(float sec) {
             ;
         }
 
-        public void Tick(float delta_sec, List<RecBallStateReport> report) {
+        public void Tick(float delta_sec) {
             lock (mStatusLock) {
                 if (!mIsPlaying || !mIsReady) return;
             }
-            
 
+            // increase delta
+            mRecRemainDelta += delta_sec;
+            if (mRecRemainDelta > REC_DELTA) {
+                var inc = (int)(mRecRemainDelta / REC_DELTA);
+                mRecStateCursor += inc;
+                mRecRemainDelta -= inc * REC_DELTA;
+            }
+
+            // check cursor
+            if (mRecStateCursor >= mRecStates.Length - 1) {
+                // try to load next sector
+                var remain = mRecStates.Length - mRecStateCursor;
+
+                lock (mStatusLock) {
+                    mIsReady = false;
+                }
+                Task.Run(() => {
+                    LoadData();
+                    mRecStateCursor = remain;
+                    mRecTrafoCursor = 0;
+                });
+
+                // return directly until next sector load successfully
+                return;
+            }
+
+            // try shift trafo cursor
+            while ((mRecTrafoCursor < mRecTrafos.Length - 1) && mRecTrafos[mRecTrafoCursor + 1].Frame <= mRecStateCursor) {
+                mRecTrafoCursor++;
+            }
+
+            // otherwise, output data
+            RecNewBallState?.Invoke(new RecBallStateReport() {
+                BallState = mRecStates[mRecStateCursor].Slerp(mRecStates[mRecStateCursor + 1], mRecRemainDelta / REC_DELTA),
+                BallType = mRecTrafos[mRecTrafoCursor].TrafoType,
+                Identifier = 0
+            });
+        }
+
+        public string GetProfile() {
+            lock (mStatusLock) {
+                return $@"Rec folder: {mFileFolder}
+Rec folder cursor: {mFileCursor}
+Rec folder type: {mFileType}
+Rec ready/play status: {mIsReady}/{mIsPlaying}
+SubRec HS/SR: {mRecHSScore}/{mRecSRScore}
+SubRec state/trafo size: {mRecStates?.Length}/{mRecTrafos?.Length}";
+            }
         }
     }
 }
diff --git a/src/scripts/cores/utils/BallStates.cs b/src/scripts/cores/utils/BallStates.cs
index 69de133..0af3618 100644
--- a/src/scripts/cores/utils/BallStates.cs
+++ b/src/scripts/cores/utils/BallStates.cs
@@ -1,30 +1,144 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading.Tasks;
 
 namespace BallanceStalker.Cores.Utils {
-    public enum BallType : UInt32 {
+    public enum VxBallType : UInt32 {
         Stone,
         Wood,
         Paper
     }
 
-    public struct VxVector {
-        float X, Y, Z;
-    }
-    public struct VxQuaternion {
-        float X, Y, Z, W;
+    public static class QuaternionHelper {
+        public static float Dot(this System.Numerics.Quaternion f, System.Numerics.Quaternion p_to) {
+            return f.X * p_to.X + f.Y * p_to.Y + f.Z * p_to.Z + f.W * p_to.W;
+        }
+        public static System.Numerics.Quaternion Slerp(this System.Numerics.Quaternion f, System.Numerics.Quaternion p_to, float delta) {
+            float omega, cosom, sinom, scale0, scale1;
+
+            // calc cosine
+            cosom = f.Dot(p_to);
+
+            // adjust signs (if necessary)
+            bool is_minus = cosom < 0f;
+            if (is_minus) cosom = -cosom;
+
+            // calculate coefficients
+            if ((1f - cosom) >= 0.01f) {
+                // standard case (slerp)
+                omega = (float)Math.Acos(cosom);
+                sinom = (float)Math.Sin(omega);
+                scale0 = (float)Math.Sin((1.0 - delta) * omega) / sinom;
+                scale1 = (float)Math.Sin(delta * omega) / sinom;
+            } else {
+                // "from" and "to" quaternions are very close
+                //  ... so we can do a linear interpolation
+                scale0 = 1.0f - delta;
+                scale1 = delta;
+            }
+
+            // adjust signs (if necessary)
+            if (is_minus) scale1 = -scale1;
+
+            return f * scale0 + p_to * scale1;
+        }
     }
+
+    //public struct VxVector {
+    //    public VxVector(float x, float y, float z) {
+    //        X = x;
+    //        Y = y;
+    //        Z = z;
+    //    }
+    //    public float X;
+    //    public float Y;
+    //    public float Z;
+
+    //    public static VxVector operator+(VxVector a, VxVector b) {
+    //        return new VxVector(a.X + b.X, a.Y + b.Y, a.Z + b.Z);
+    //    }
+    //    public static VxVector operator -(VxVector a, VxVector b) {
+    //        return new VxVector(a.X - b.X, a.Y - b.Y, a.Z - b.Z);
+    //    }
+    //    public static VxVector operator *(float m, VxVector a) {
+    //        return new VxVector(m * a.X, m * a.Y, m * a.Z);
+    //    }
+    //    public static VxVector operator *(VxVector a, float m) {
+    //        return new VxVector(m * a.X, m * a.Y, m * a.Z);
+    //    }
+    //    public static VxVector operator /(VxVector a, float m) {
+    //        return new VxVector(a.X / m, a.Y / m, a.Z / m);
+    //    }
+    //}
+    //public struct VxQuaternion {
+    //    public VxQuaternion(float x, float y, float z, float w) {
+    //        X = x;
+    //        Y = y;
+    //        Z = z;
+    //        W = w;
+    //    }
+    //    public float X;
+    //    public float Y;
+    //    public float Z;
+    //    public float W;
+    //    public float Dot(VxQuaternion p_to) {
+    //        return X * p_to.X + Y * p_to.Y + Z * p_to.Z + W * p_to.W;
+    //    }
+    //    // Reference: https://github.com/godotengine/godot/blob/master/core/math/quaternion.cpp
+    //    public VxQuaternion Slerp(VxQuaternion p_to, float delta) {
+    //        float omega, cosom, sinom, scale0, scale1;
+
+    //        // calc cosine
+    //        cosom = Dot(p_to);
+
+    //        // adjust signs (if necessary)
+    //        bool is_minus = cosom < 0f;
+    //        if (is_minus) cosom = -cosom;
+
+    //        // calculate coefficients
+    //        if ((1f - cosom) >= 0.01f) {
+    //            // standard case (slerp)
+    //            omega = (float)Math.Acos(cosom);
+    //            sinom = (float)Math.Sin(omega);
+    //            scale0 = (float)Math.Sin((1.0 - delta) * omega) / sinom;
+    //            scale1 = (float)Math.Sin(delta * omega) / sinom;
+    //        } else {
+    //            // "from" and "to" quaternions are very close
+    //            //  ... so we can do a linear interpolation
+    //            scale0 = 1.0f - delta;
+    //            scale1 = delta;
+    //        }
+
+    //        // adjust signs (if necessary)
+    //        if (is_minus) scale1 = -scale1;
+
+    //        return new VxQuaternion(
+    //            scale0 * X + scale1 * p_to.X,
+    //            scale0 * Y + scale1 * p_to.Y,
+    //            scale0 * Z + scale1 * p_to.Z,
+    //            scale0 * W + scale1 * p_to.W
+    //        );
+    //    }
+
+    //}
     public struct VxBallState {
-        VxVector Pos;
-        VxQuaternion Quat;
+        public System.Numerics.Vector3 Pos;
+        public System.Numerics.Quaternion Quat;
+        public VxBallState Slerp(VxBallState to, float delta) {
+            return new VxBallState() {
+                Pos = (to.Pos - this.Pos) * delta + this.Pos,
+                Quat = this.Quat.Slerp(to.Quat, delta)
+            };
+        }
     }
 
     public struct RecBallStateReport {
-        long Identifier;
-        VxBallState BallState;
+        public long Identifier;
+        public VxBallType BallType;
+        public VxBallState BallState;
     }
 
 }
diff --git a/src/scripts/cores/utils/IRec.cs b/src/scripts/cores/utils/IRec.cs
index 167007a..5113f4d 100644
--- a/src/scripts/cores/utils/IRec.cs
+++ b/src/scripts/cores/utils/IRec.cs
@@ -6,18 +6,23 @@ using System.Threading.Tasks;
 
 namespace BallanceStalker.Cores.Utils {
     public interface IRec {
+        void Startup();
+        void Shutdown();
         void Play();
         void Pause();
         void Seek(float sec);
-        void Tick(float delta_sec, List<RecBallStateReport> report);
+        void Tick(float delta_sec);
+        string GetProfile();
 
         /// <summary>
         /// register a ball
         /// long is identifier, string is name
         /// </summary>
         event Action<long, string> RecRegisterBall;
-        event Action RecPlaying;
-        event Action RecPaused;
+        event Action<RecBallStateReport> RecNewBallState;
+        event Action<List<RecBallStateReport>> RecNewBallStates;
+        //event Action RecPlaying;
+        //event Action RecPaused;
         /// <summary>
         /// unregister a ball
         /// long is identifier