koobas.hobune.stream
Sending texture updates from client to server
I'm working on a multiplayer sample wherein player's can see each other while playing. Currently, I just want to send the updated webcam video as png images over the network (will worry about compression/encoding later). I'm unsure how to accomplish this.
Initially, I thought I'd have a component attached to my player prefab, say PlayerVideo that overrides the OnSerialize and OnDeserialize methods -- however, these functions seem to be for the server to send specific updates to the clients (i.e., your own SyncVar functionality)
It seemed like Commands and ClientRPC calls are what I needed. The flow being:
PlayerVideo.Update() --> GetWebCamFeed() --> SendToServer --> CmdVideoTextureUpdate --> RpcUpdateVideoTexture
How do I send these texture data to the server and from the server to the clients though? I don't understand how exactly to use NetworkWriter and NetworkReader to accomplish this.
Here's some code:
void Update()
{
// Send server the updated video texture data as a NetworkWriter object
if (isLocalPlayer)
{
byte[] textureData = m_playerVideoTexture.EncodeToPNG();
NetworkWriter writer = new NetworkWriter();
writer.WriteBytesFull(textureData);
CmdVideoTextureUpdate(writer);
}
}
[Command]
void CmdVideoTextureUpdate(NetworkWriter writer)
{
// argument should be NetworkReader, instead it's writer.. how to fix?
RpcUpdateVideoTexture(textureData);
}
[ClientRpc]
void RpcUpdateVideoTexture(NetworkReader reader)
{
if (isLocalPlayer)
return;
byte[] textureData = reader.ReadBytesAndSize();
m_playerVideoTexture.LoadImage(textureData);
m_playerVideoTexture.Apply();
}
How do I convert the NetworkWriter object to a NetworkReader object for the clientrpc to use? Or is this just the wrong way to do this in the first place?
you could use NetworkWriter.ToArray() and send the array of bytes, then construct a NetworkReader from the array of bytes.
Thanks for helping out Sean! I didn't quite get what you meant. Can a command/clientrpc have a byte[] argument (and Unity takes care of serializing it and sending it down as a message)? i.e.
[Command]
void CmdVideoTextureUpdate(byte[] data) {
RpcUpdateVideoTexture(data);
}
[ClientRpc]
void RpcUpdateVideoTexture(byte[] data)
{
if (isLocalPlayer)
return;
m_playerVideoTexture.LoadImage(data);
m_playerVideoTexture.Apply();
}
If I send a network message with the data, I'd have to route the data to the right network object. Is that correct?
Thanks @seanr, so I tried it and it seems like the PNG encoded texture byte data (haven't added video encoding yet) is too large.
UnityException: NetworkWriter used buffer is too big!
UnityEngine.Networking.NetworkServer.SendWriterToReady (UnityEngine.GameObject contextObj, UnityEngine.Networking.NetworkWriter writer, Int32 channelId) (at C:/buildslave/unity/build/Extensions/Networking/Runtime/NetworkServer.cs:333)
Is there something I can do to work around it? Or would message passing be the alternative (with messages, it seems like i'd have to have a global client message handler and have to do a per-player-texture-data-sync manually)
there is a limit of (about) 1400 bytes on regular messages. If you use a fragmented channel, the limit is 32$$anonymous$$. You would add a fragmented channel to the QoS channels in the Network$$anonymous$$anager settings, then use [Command(channel=3)] where 3 is the new channel index.
