问题
这个Command 方法总是在服务器上执行......所以也使用属性在服务器上。
含义：
你永远不会在客户端设置playerGun，只在服务器上
playerGun = Instantiate ...
因此，由于您的客户端永远不会获得其playerGun 值集，因此CarryGun 永远不会在客户端上执行。
解决方案 1
为避免您应该使用ClientRpc 方法在所有客户端上设置该值。
[Command]
public void CmdGetGun()
{
Debug.Log("SPAWNING A GUN");
playerGun = (GameObject)Instantiate(gunPrefab, transform.position, transform.rotation);
NetworkServer.SpawnWithClientAuthority(playerGun, connectionToClient);
// Tell the clients to set the playerGun reference.
// You can pass it as GameObject since it has a NetworkIdentity
RpcSetGunOnClients(playerGun);
}
// Executed on ALL clients
// (which does not mean on all components but just the one of
// this synched GameObject, just to be clear)
[ClientRpc]
private void RpcSetGunOnClients (GameObject gun)
{
playerGun = gun;
}
解决方案 2
这是一个替代解决方案，它与上面的步骤基本相同但它不再需要CarryGun 方法和NetworkTransform，通过保存这两个方法使您的代码更高效通话和网络带宽：
而不是在层次结构的顶层生成枪到某个全局位置和旋转
playerGun = (GameObject)Instantiate(gunPrefab, transform.position, transform.rotation);
除了将它的位置和旋转一直更新到玩家的 tranfroms 并通过 NetworkTransforms 单独传输它们之外，您可以简单地使用例如使其成为 Player 对象本身的子对象。服务器上的Instantiate(Object original, Vector3 position, Quaternion rotation, Transform parent); ：
playerGun = (GameObject)Instantiate(gunPrefab, gunLocalPositionOffset, gunLocalRotationOffset, transform);
这应该始终将其保持在正确的位置，而无需 Update 并始终同步其位置和旋转，并且无需任何进一步的传输方法和值。
您所要做的就是再次拥有一个ClientRpc，以便告诉客户也让这把枪成为您的玩家的孩子，例如使用SetParent(Trasnform parent, bool worldPositionStays):
playerGun.transform.SetParent(transform, false);
并在必要时应用本地位置和旋转偏移。同样，您可以使用一个值，每个人都可以从服务器访问或将其传递给 ClientRpc - 您的选择；）
所以你的方法现在看起来像
// In order to spawn the gun with an offset later
// It is up to you where those values should come from / be passed arround
// If you crate your Prefab "correctly" you don't need them at all
//
// correctly means: the most top GameObject of the prefab has the
// default values position(0,0,0) and rotation (0,0,0) and the gun fits perfect
// when the prefab is a child of the Player => You don't need any offsets at all
Vector3 gunLocalPositionOffset= Vector3.zero;
Quaternion gunLocalRotationOffset= Quaternion.identity;
[Command]
public void CmdGetGun()
{
Debug.Log("SPAWNING A GUN");
// instantiates the prefab as child of this gameObject
// you still can spawn it with a local offset position
// This will make its position be already synched in the Players own
// NetworkTransform -> no need for a second one
playerGun = (GameObject)Instantiate(gunPrefab, gunLocalPositionOffset, gunLocalRotationOffset, gameobject);
// you wouldn't need this anymore since you won't change the spoition manually
// NetworkServer.SpawnWithClientAuthority(playerGun, connectionToClient);
NetworkServer.Spawn(playerGun);
// Tell the clients to set the playerGun reference.
// You can pass it as GameObject since it has a NetworkIdentity
RpcSetGunOnClients(playerGun);
}
// Executed on all clients
[ClientRpc]
private void RpcSetGunOnClients (GameObject gun)
{
// set the reference
playerGun = gun;
// NetworkServer.Spawn or NetworkServer.SpawnWithClientAuthority doesn't apply
// the hierachy so on the Client we also have to make the gun a child of the player manually
// use the flag worldPositionStays to avoid a localPosition offset
playerGun.transform.SetParent(transform, false);
// just to be very sure you also could (re)set the local position and rotation offset later
playerGun.transform.localPosition = gunLocalPositionOffset;
playerGun.transform.localrotation = gunLocalRotationOffset;
}
更新1
如需解决后来连接的客户端问题，请参阅this answer。
它建议使用[SyncVar] 并覆盖OnStartClient。采用的版本可能看起来像
// Will be synched to the clients
// In our case we know the parent but need the reference to the GunObject
[SyncVar] public NetworkInstanceId playerGunNetId;
[Command]
public void CmdGetGun()
{
Debug.Log("SPAWNING A GUN");
playerGun = (GameObject)Instantiate(gunPrefab, gunLocalPositionOffset, gunLocalRotationOffset, transform);
// Set the playerGunNetId on the Server
// SyncVar will set on all clients including
// newly connected clients
playerGunNetId = playerGun.GetComponent<NetworkIdentity>().netId;
NetworkServer.Spawn(playerGun);
RpcSetGunOnClients(playerGun);
}
public override void OnStartClient()
{
// When we are spawned on the client,
// find the gun object using its ID,
// and set it to be our child
GameObject gunObject = ClientScene.FindLocalObject(playerGunNetId);
gunObject.transform.SetParent(transform, false);
gunObject.transform.localPosition = gunLocalPositionOffset;
gunObject.transform.localrotation = gunLocalRotationOffset;
}
（注意对于已连接的客户端，您仍然需要ClientRpc。）
更新2
Update1 中的方法可能不起作用，因为在执行 OnStartPlayer 时可能尚未设置 playetGunNetId。
要克服这个问题，您可以将hook method 用于我们的SyncVar。类似的东西
// The null reference might somehow still come from
// ClientScene.FindLocalObject
[SyncVar(hook = "OnGunIdChanged"]
private NetworkInstanceId playerGunNetId;
// This method is executed on all clients when the playerGunNetId value changes.
// Works when clients are already connected and also for new connections
private void OnGunIdChanged (NetworkInstanceId newValue)
{
// Honestly I'm never sure if this is needed or not...
// but in worst case it's just redundant
playerGunNetId = newValue;
GameObject gunObject = ClientScene.FindLocalObject(playerGunNetId);
gunObject.transform.SetParent(transform, false);
gunObject.transform.localPosition = gunLocalPositionOffset;
gunObject.transform.localrotation = gunLocalRotationOffset;
}
现在您甚至不再需要 ClientRpc，因为对于已连接和新连接的客户端，一切都由 hook 处理。