(24-05-2021, 07:32 AM)pmike Wrote: Hello! Does anyone have any code or ideas for serializing/deserializing a rope over a network?

(24-05-2021, 07:41 AM)josemendez Wrote: You do this just like you'd do with any other object: send positions and velocities over. In Obi's case, particle positions and velocities.

If you're using UDP, passing a timestamp would be a good idea too. Client side you can implement dead reckoning by just letting the simulation run in-between snapshots.

You can get/set per-particle data (positions, velocities, etc) using the particles API:
http://obi.virtualmethodstudio.com/tutorials/scriptingparticles.html

(24-05-2021, 08:05 AM)pmike Wrote: Can you give a sample code for saving and loading the rope state using particles API?

(24-05-2021, 08:27 AM)josemendez Wrote: There's sample code for this in the link I just posted. To read:

Code:

for (int i = 0; i < actor.solverIndices.Length; ++i)
{
    int solverIndex = actor.solverIndices[i];
    var pos = actor.solver.positions[solverIndex];
    var vel =  actor.solver.velocities[solverIndex];
}

To write:

Code:

for (int i = 0; i < actor.solverIndices.Length; ++i)
{
    int solverIndex = actor.solverIndices[i];
    actor.solver.positions[solverIndex] = yourPos;
    actor.solver.velocities[solverIndex] = yourVel;
}

(24-05-2021, 12:16 PM)pmike Wrote: Another question: how to effectively serialize and deserialize object of type ObiNativeVector4List? 

Direct serialization via BinaryFormatter does not work:

SerializationException: Type 'Obi.ObiNativeList`1[[UnityEngine.Vector4, UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]]' in Assembly 'Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' is not marked as serializable.

But type


namespace Obi
{
    [Serializable]
    public class ObiNativeVector4List : ObiNativeList<Vector4>
    { ...

(24-05-2021, 12:26 PM)josemendez Wrote: ObiNativeList internally holds a raw pointer to unmanaged data, so BinaryFormatter won't work. Furthermore, serializing the entire list does not make much sense in this context, as you're interested in the data for each individual actor, not the entire solver. There's no guarantee data belonging to different actors will be laid out in memory in exactly the same way in different machines.

Internally we use Unity's ISerializationCallbackReceiver interface to manually serialize/deserialize this data using unsafe operations (Unity.Collections.LowLevel.Unsafe), however this is *unsafe* as the name implies and can easily crash if you're not 100% sure of what you're doing.

Easiest way is probably to just iterate trough the list manually and serialize each entry to a format of your choice.

(27-05-2021, 08:28 AM)pmike Wrote: Hello! 
One more question. How can I pause the rope after loading the state, i.e. turn it into a "static spline" for a while?