同步器插件

• The Running Syncker for a custom project article for more details on Syncker initialization and synchronization code.这为自定义项目运行 Syncker有关 Syncker 初始化和同步代码的更多详细信息，请参阅文章。
• The Syncker-specific options article for more details on Syncker command-line options and console commands.这Syncker 特定选项有关 Syncker 命令行选项和控制台命令的更多详细信息，请参阅文章。
• The article on SpiderVision Plugin for more details on the setup of multi-monitor Slave configurations.关于SpiderVision Plugin的文章详细介绍了多监视器Slave配置的设置。

Syncker API:

• The Manager interface article for more details on managing Syncker via code (C++, C#, UnigineScript).有关通过代码（C++、C#、UnigineScript）管理 Syncker 的更多详细信息，请参阅 Manager 接口文章。
• The Master interface article for more details on managing Syncker Master via code (C++, C#, UnigineScript).有关通过代码（C++、C#、UnigineScript）管理 Syncker Master 的更多详细信息，请参阅 Master 接口文章。
• The Slave interface article for more details on managing Syncker Slave via code (C++, C#, UnigineScript).有关通过代码（C++、C#、UnigineScript）管理 Syncker Slave 的更多详细信息，请参阅 Slave 接口文章。

The order of launching Master and Slave applications does not matter: you can launch several Slave apps, then Master, and then the remaining Slave apps — synchronization will start automatically. Master starts the session as soon as all Slave apps are connected.启动 Master 和 Slave 应用程序的顺序无关紧要：您可以启动多个 Slave 应用程序，然后是 Master 应用程序，然后是其余的 Slave 应用程序——同步将自动开始。一旦连接了所有 Slave 应用程序，Master 就会启动会话。

In case only Master is present (-sync_count 1) and connection of additional Slave applications on the fly is enabled (-sync_allow_extra_slaves 1), the session starts immediately and lasts forever (until Master is on).如果仅存在 Master (-sync_count 1) 并且启用了其他 Slave 应用程序的动态连接 (-sync_allow_extra_slaves 1)，则会话会立即开始并永远持续（直到 Master 开启）。

Syncker works in Asynchronous mode providing synchronization between the channels by means of reconstruction using the data of previous frames. In asynchronous mode all computers draw their own frames, each with its own frame rate. So, in this mode we synchronize time.Syncker 工作在 异步模式下，通过使用前一帧的数据重建，提供通道之间的同步。在异步模式下，所有计算机都绘制自己的帧，每个帧都有自己的帧速率。所以，在这种模式下，我们同步时间。

In case there are a lot of Slave applications used, resulting in significant growth of the network load, it is recommended to try and reduce load by enabling broadcast or multicast addressing modes. If changing the addressing mode does not solve the problem, you are recommended to adjust send rate, interpolation/extrapolation parameters.如果使用了很多 Slave 应用程序，导致网络负载显着增长，建议尝试通过启用 broadcast 或 multicast 寻址模式来减少负载。如果改变寻址方式不能解决问题，建议调整发送速率、插值/外插参数。

UNIGINE Syncker uses Interpolated Snapshots (IS) to tackle with the problem of lost packets between Master and Slave. It works by taking two old, but known positions and interpolating the object between them. It is accomplished by having a buffer of received positions and rotations, along with the time they represent. We usually take our current local time minus some predefined amount — interpolation period (40 ms by default), then go into our buffer, find the two indices that are just before and just after this time and interpolate.UNIGINE Syncker 使用内插快照(IS) 来解决 Master 和 Slave 之间丢失数据包的问题。它的工作原理是取两个旧的但已知的位置并在它们之间插入对象。它是通过接收位置和旋转以及它们代表的时间的缓冲区来实现的。我们通常将当前本地时间减去一些预定义的时间——插值周期（默认为 40 ms），然后进入我们的缓冲区，找到这个时间之前和之后的两个索引并进行插值。

If we don't have a received position and rotation for the time we're looking for, the extrapolation (guessing) is used. It also has a limited time — extrapolation period (200 ms by default). If the extrapolation period is over but there are still no packets received, all objects will freeze.如果我们在寻找的时间内没有收到位置和旋转，则使用外推法（猜测）。它还有一个有限的时间——外推周期（默认为 200 ms）。如果外推期结束但仍未收到数据包，则所有对象都将冻结。

In most cases, this method provides a very accurate representation of the world to each Slave, as in general only already known positions of remote objects are rendered and in rare cases the system will try to extrapolate (guess) where an object is. This, however, comes at a cost, as we always render 40 ms (interpolation period) behind current time, so that new packets have time to arrive with data.在大多数情况下，此方法为每个 Slave 提供了非常准确的世界表示，因为通常只渲染远程对象的已知位置，并且在极少数情况下，系统会尝试推断（猜测）对象的位置。然而，这是有代价的，因为我们总是在当前时间之后渲染 40 ms（插值周期），以便新数据包有时间与数据一起到达。

Basically, you can use the following delivery modes for sending/receiving messages:基本上，您可以使用以下交付模式来发送/接收消息：

• Reliable — Reliable and sequenced mode, enabled by default. All packets shall be delivered to the recipient in the exact order they were sent.Reliable — 可靠且有序的模式，默认启用。所有数据包都应按照它们被发送的确切顺序传送给接收者。

• Unreliable — Pure UDP. Packets may be lost, duplicated, or received in an order that differs from the one they were sent. Packets are not compressed, fragmented, or merged. Everything is sent "as is". This mode is the fastest one as it requires no additional time for processing. You can use this mode for sending timestamped auxiliary data (e.g., for interpolation) having the size close to MTU. Unreliable — 纯 UDP。数据包可能会丢失、复制或接收顺序与发送顺序不同。数据包不会被压缩、碎片化或合并。一切都按“原样”发送。这种模式是最快的，因为它不需要额外的处理时间。您可以使用此模式发送大小接近 MTU 的带时间戳的辅助数据（例如，用于插值）。

  Example: sending 10 times a second positions of 10 aircrafts with the information on the current time, status of flaps, slats, ailerons, landing gears, etc.示例：每秒 10 次发送 10 架飞机的位置信息，包括当前时间、襟翼、缝翼、副翼、起落架等的状态。

• 

  Sequenced — Packets may be lost, but never duplicated, they arrive in the exact order they were sent. This mode can be used for sending auxiliary data having the size close to MTU.Sequenced — Packets may be lost, but never duplicated, they arrive in the exact order they were sent. This mode can be used for sending auxiliary data having the size close to MTU.

  Example: sending each frame positions of 10 aircrafts with the information on the status of flaps, slats, ailerons, landing gears, etc.Example: sending each frame positions of 10 aircrafts with the information on the status of flaps, slats, ailerons, landing gears, etc.

  Sequenced — Packets may be lost, but never duplicated, they arrive in the exact order they were sent. This mode can be used for sending auxiliary data having the size close to MTU.Example: sending each frame positions of 10 aircrafts with the information on the status of flaps, slats, ailerons, landing gears, etc.

  Sequenced — Packets may be lost, but never duplicated, they arrive in the exact order they were sent. This mode can be used for sending auxiliary data having the size close to MTU.Sequenced — 数据包可能会丢失，但不会被复制，它们按照发送的确切顺序到达。此模式可用于发送大小接近 MTU的辅助数据。

  Example: sending each frame positions of 10 aircrafts with the information on the status of flaps, slats, ailerons, landing gears, etc.示例：每帧发送10架飞机的位置信息，包括襟翼、缝翼、副翼、起落架等状态信息。

Multiple systems may use the Syncker's network simultaneously (e.g. IG and a user's App application). For convenience, all messages are sent and received via named channels. If the specified channel does not exist, it shall be created.多个系统可以同时使用 Syncker 的网络（例如 IG 和用户的 App 应用程序）。为方便起见，所有消息都通过命名通道发送和接收。如果指定的通道不存在，则应创建它。

The following addressing modes for communication are available:可以使用以下通信寻址模式：

• Unicast
• Multicast
• Broadcast

Depending on your project's requirements, you can choose the one that fits best: ensures the lowest possible load, or provides additional features like easy testing on a single PC or communication between hosts from different subnets using different ports.根据您的项目要求，您可以选择最适合的一个：确保尽可能低的负载，或提供附加功能，例如在单台 PC 上轻松测试或使用不同端口的来自不同子网的主机之间的通信。

最佳实践

Unicast mode is recommended to be used during the development stage as the most flexible one, while Multicast and Broadcast are considered as options for production. Broadcast mode is the best option if the network consists of IG-hosts only.开发阶段推荐使用Unicast模式，作为最灵活的一种，而Multicast和Broadcast被认为是生产的选项。如果网络仅由 IG 主机组成，则 Broadcast 模式是最佳选择。

Broadcast
Master sends packets to all computers in the network. Messages are received by Slave computers as well as by all other computers which are irrelevant to the Synker.Master 向网络中的所有计算机发送数据包。消息由 Slave 计算机以及与 Synker 无关的所有其他计算机接收。 注意 All host computers must be in the same subnet and use the same port.所有主机计算机必须在同一个子网中并使用同一个端口。 Advantages:好处： Reduced load on the Master host (only one packet is to be sent instead of sending one separate copy of it to each Slave).减少 Master 主机上的负载（只发送一个数据包，而不是向每个 Slave 发送一个单独的副本）。 Simple setup (simply set the broadcasting mode for Master via -sync_method broadcast设置简单（只需通过 -sync_method broadcast 设置 Master 的广播模式 Disadvantages:缺点： Impossible to test on a single computer.无法在单台计算机上进行测试。 Messages are received to all computers in the network (even the ones irrelevant to the Synker) resulting in a significant load on a network, router, and computers themselves in case the network contains a lot of such computers.网络中的所有计算机（即使是与 Synker 无关的计算机）都会收到消息，这会导致网络、路由器和计算机本身的大量负载，以防网络包含大量此类计算机。
Unicast
Master sends messages only to its Slave apps: a separate copy of the message is sent to each Slave.Master 仅向其 Slave 应用程序发送消息：将单独的消息副本发送到每个 Slave。 注意 All host computers can be in different subnets and use any ports (except for Master).所有主机都可以位于不同的子网中并使用任何端口（Master 除外）。 Advantages:好处： Simple setup (works by default).简单的设置（默认工作）。 Computers can belong to different subnets (e.g. several computers from LAN plus several connected via WiFi).计算机可以属于不同的子网（例如，来自 LAN 的多台计算机以及通过 WiFi 连接的多台计算机）。 Messages from Master are received only by its Slave apps.来自 Master 的消息仅由其 Slave 应用程序接收。 Easy to test on a single computer.易于在单台计算机上进行测试。 No restrictions except for an exactly defined port for Master.除了为 Master 精确定义的端口外，没有任何限制。 Disadvantages:缺点： Significant number of Slave apps increases load on the network segment between Master and router, as a separate copy must be sent to each Slave.大量 Slave 应用程序增加了 Master 和路由器之间网段的负载，因为必须向每个 Slave 发送单独的副本。 注意 Switching to Multicast/Broadcast modes helps reducing the network load in case of a growing number of Slaves. As in these modes the load is almost unaffected, unlike Unicast, where the load is proportional to the number os Slaves.在 Slave 数量增加的情况下，切换到 Multicast/Broadcast 模式有助于减少网络负载。在这些模式中，负载几乎不受影响，这与 Unicast 不同，其中负载与 os Slaves 的数量成正比。
Multicast
Master sends a message to a unique multicast address, and the router redirects this message only to the computers that "listen" to this address (have joined the multicast group).Master 向唯一的多播地址发送消息，路由器仅将此消息重定向到“侦听”此地址的计算机（已加入 multicast 组）。 注意 All computers must use the same port. Master should know the multicast address, while Slave apps should be connected to the same multicast group.所有计算机必须使用相同的端口。 Master 应该知道多播地址，而 Slave 应用程序应该连接到同一个 multicast 组。 Advantages:好处： Lowest possible load on Master and network.Master 和网络上的最低负载。 Master sends the message only once, Slave apps receive the copies of the same message.Master 只发送一次消息，Slave 应用程序接收同一消息的副本。 Copies of the message are received by Slave PCs only, other PCs in the network don't receive them.消息的副本仅由 Slave PC 接收，网络中的其他 PC 不会收到它们。 Disadvantages:缺点： More settings to be configured.更多设置需要配置。 Router's default settings may result in blocking Syncker packets. You might need to change these settings to avoid it.路由器的默认设置可能会导致阻塞 Syncker 数据包。您可能需要更改这些设置以避免它。 Impossible to test on a single computer.无法在单台计算机上进行测试。

Summarizing the information from the table above as related to the network traffic load:总结上表中与网络流量负载相关的信息：

• The Multicast mode generates the minimum network traffic, as compared to other modes, thus creating the least load on the router and wi-fi.与其他模式相比，Multicast 模式产生的网络流量最小，从而在路由器和 wi-fi 上产生最少的负载。
• The Broadcast mode can be more consuming, because the packets are sent to all network PCs, including those that are not Slave (if any). If you don't have any other PCs in your network except for Slave ones, then the traffic amount will be the same as in the Multicast mode.Broadcast 模式可能更消耗，因为数据包被发送到所有网络 PC，包括那些不是 Slave（如果有）。如果您的网络中除了 Slave 之外没有任何其他 PC，那么流量将与 Multicast 模式相同。
• The Unicast mode generates amount of network traffic that can be calculated as Multicast * number of Slave PCs.Unicast 模式产生的网络流量可以计算为Multicast * Slave PC 的数量。

To further optimize the traffic load, you can increase the time intervals for packets sending:为了进一步优化流量负载，您可以增加发送数据包的时间间隔：

//On the Master
	master->setSendRate(15.0f); // send packets 15 times per second

	//Both on the Master and all Slaves
	syncker->setInterpolationPeriod(0.1f); // 100 ms delay

In this example, packets will be sent only 15 times per second, thus the lag will make 100 ms.在此示例中，数据包每秒仅发送 15 次，因此延迟将达到 100 毫秒。

Consequently, reducing the lag (interpolation period) requires increasing the send rate, which will affect the network load:因此，减少滞后（插值周期）需要增加发送速率，这会影响网络负载：

//On the Master
	master->setSendRate(30.0f); // send packets 30 times per second

	//Both on the Master and all Slaves
	syncker->setInterpolationPeriod(0.05f); // 50 ms delay