Network transform prediction

Hi... here's a translated version of the Network Tutorials "NetworkInterpolatedTransform.cs" into JavaScript. It helps with the network transform predictions. I couldn't get the C# version of the script to work with my CharacterControllers, and perhaps someone else might need this script.

Code (csharp):

1.  
2. var interpolationBackTime = 0.1;
3.  
4. private var m_BufferedState : Array = new State[20]; // where we store the State of our controller
5. private var m_TimestampCount : int; // keeps track of what slots are used
6.  
7.  
8. // Holds information about the controllers movements and last sent information from the network
9. class State
10. {
11.     var timeStamp : float;
12.     var pos : Vector3;
13.     var rot : Quaternion;
14. }
15.  
16. function OnSerializeNetworkView(stream : BitStream, info : NetworkMessageInfo)
17. {
18.     if (stream.isWriting)
19.     {
20.         var pos = transform.position;
21.         var rot = transform.rotation;
22.        
23.         stream.Serialize(pos);
24.         stream.Serialize(rot);
25.     }
26.     else
27.     {
28.         pos = Vector3.zero;
29.         rot = Quaternion.identity;
30.         stream.Serialize(pos);
31.         stream.Serialize(rot);
32.        
33.        
34.         for (var i = m_BufferedState.length - 1; i >= 1; i --)
35.         {
36.             m_BufferedState[i] = m_BufferedState[i-1];
37.         }
38.        
39.         var state = new State();
40.         state.timeStamp = info.timestamp;
41.         state.pos = pos;
42.         state.rot = rot;
43.         m_BufferedState[0] = state;
44.        
45.         m_TimestampCount = Mathf.Min(m_TimestampCount + 1, m_BufferedState.length);
46.        
47.         for (i = 0; i < m_TimestampCount-1; i++)
48.         {
49.             if (m_BufferedState[i].timeStamp < m_BufferedState[i+1].timeStamp)
50.             {
51.                 Debug.Log("State inconsistent");
52.             }
53.         }
54.     }
55. }
56.  
57. function Update ()
58. {
59.     if (!networkView.isMine)
60.     {      
61.         var currentTime = Network.time;
62.         var interpolationTime = currentTime - interpolationBackTime;
63.    
64.         if (m_BufferedState[0] != null  m_BufferedState[0].timeStamp > interpolationTime)
65.         {
66.             for (var i = 0; i < m_TimestampCount; i++)
67.             {
68.                 if (m_BufferedState[i].timeStamp <= interpolationTime || i == m_TimestampCount - 1)
69.                 {
70.                     // The state one slot newer (<100ms) than the best playback state
71.                     var rhs : State = m_BufferedState[Mathf.Max(i-1, 0)];
72.                     // The best playback state (closest to 100 ms old (default time))
73.                     var lhs : State = m_BufferedState[i];
74.                    
75.                     // Use the time between the two slots to determine if interpolation is necessary
76.                     var length = rhs.timeStamp - lhs.timeStamp;
77.                     var t : float = 0.0;
78.                    
79.                     if (length > 0.0001)
80.                     {
81.                         t = ((interpolationTime - lhs.timeStamp) / length);
82.                     }
83.                    
84.                     // if t=0 => lhs is used directly
85.                     transform.position = Vector3.Lerp(lhs.pos, rhs.pos, t);
86.                     transform.rotation = Quaternion.Slerp(lhs.rot, rhs.rot, t);
87.                     return;
88.                    
89.                 }
90.             }
91.         }
92.         else
93.         {
94.             if (m_BufferedState[0] != null)
95.             {
96.                 var latest = m_BufferedState[0];
97.                 transform.position = latest.pos;
98.                 transform.rotation = latest.rot;
99.             }
100.         }
101.     }
102. }
103.  
104.  

To use it, just drop the script onto your CharacterController, attach a NetworkView, and set the NetworkView to observe the script. Good luck...

 

I owe you a thank you. Since I am using this.

Thanks for sharing.