引擎体系结构

There are different approaches to setting up game architecture, ranging from all-in-one solutions, where game logic is fused with an engine, to a heap of separate modules, each of which is responsible for one part of functionality. Unigine is somewhere in the middle of this scale, it incorporates everything one needs to implement a game or other 3D application, except for the application logic, networking, and AI. Unigine includes only typical game logic, common for applications of all types, and this is done intentionally.设置游戏架构的方法多种多样，从将游戏逻辑与引擎融合在一起的多合一解决方案，到一堆单独的模块，每个模块负责功能的一部分。 Unigine处于这种规模的中间位置，它融合了实现游戏或其他3D应用程序所需的一切，除了应用程序逻辑，网络和AI。 Unigine仅包含典型的游戏逻辑，适用于所有类型的应用程序，并且是有意完成的。

This may not seem an advantage, because in order to create a game, one needs to do a great deal of programming and by themselves implement common functionality widely used in games of the required genre. However, lack of the genre-specific game logic is not so bad, as it makes Unigine a general-purpose library, easily re-usable in different projects. Moreover, developers are not bound to some specific genre, they can experiment with several genres at once, which is extremely difficult if a special-purpose engine is used. For example, it's difficult to make a mix of a shooter and a racing game out of an engine created solely for first-person shooters. Also, Unigine allows plugging of external modules, which can contain genre-specific functionality and can be re-used, too. This all makes Unigine a rather flexible base for a wide range of 3D applications.这似乎不是一个优势，因为要创建一个游戏，一个人需要做大量的编程工作，并自己实现所需类型的游戏中广泛使用的通用功能。但是，缺乏特定类型的游戏逻辑并没有那么糟糕，因为它使Unigine成为通用库，可以在不同项目中轻松重用。而且，开发人员不受特定类型的束缚，他们可以一次尝试多种类型，如果使用专用引擎，这将非常困难。例如，很难使用仅为第一人称射击游戏创建的引擎来组合射击游戏和赛车游戏。此外，Unigine允许插入外部模块，这些模块可以包含特定于类型的功能，并且也可以重复使用。这一切使Unigine成为了广泛的3D应用程序的相当灵活的基础。

To understand the architecture of Unigine is very important both for developers and for content creators. The former will know what they are allowed to do, what they can achieve, and what to expect from Unigine. The latter will understand how their content is going to be processed. That is why this article provides a brief and high-level overview of the Unigine workflow.理解Unigine的体系结构对于开发人员和内容创建者都非常重要。前者将知道他们被允许做的事情，他们可以实现的事情以及对Unigine的期望。后者将了解如何处理其内容。因此，本文简要概述了Unigine工作流程。

注意

A more detailed and more programmer-oriented description of Unigine workflow can be found in the article Execution Sequence.有关Unigine工作流的更详细和面向程序员的描述，请参见文章执行序列。

The diagram below demonstrates interrelations between internal components of Unigine and different external entities.下图说明了Unigine内部组件与不同外部实体之间的相互关系。

Everything starts when the custom application logic calls Unigine API functions, These calls can be done using either UnigineScript or C/C++ directly. The former is a more preferable way, as in this case the programmer doesn't have to think about multi-threading and memory management. Also, if the application is written in UnigineScript, it will run on each platform supported by Unigine. The API component loads modules that extend the Unigine functionality, if that is required by the application logic. Such modules may contain, for example, third-party middleware.当自定义应用程序逻辑调用Unigine API函数时，一切开始。可以使用 UnigineScript 或直接使用C / C ++进行这些调用。前一种是更可取的方式，因为在这种情况下，程序员不必考虑多线程和内存管理。另外，如果应用程序是用UnigineScript编写的，它将在Unigine支持的每个平台上运行。如果应用程序逻辑要求，API组件会加载模块来扩展Unigine功能。此类模块可能包含例如第三方中间件。

API calls are passed to the interpreter, which initializes required resources: registers extensions, loads core data, configuration files, scripts, and user interface files. As all these resources are organized in a special data directory and, moreover, can be packed, they are loaded by means of the file system component. In addition, the file system component tracks the endianness of files. Note that if you add files to this directory after the initialization is completed, you need to reload the file system component. API调用传递给解释器，该解释器初始化所需的资源：注册扩展，加载核心数据，配置文件，脚本和用户界面文件。由于所有这些资源都组织在一个特殊的数据目录中，并且可以进行打包，因此它们通过文件系统组件进行加载。另外，文件系统组件跟踪文件的字节序。请注意，如果在初始化完成后将文件添加到该目录，则需要重新加载文件系统组件。

After initialization, the world manager comes into play. It loads files, which are required to build the current scene, and determines the set of visible nodes, which later will be sent to the render component. The world manager also tells the sound component, when and how to play environmental sounds, which sources are placed somewhere in the world and have spatial properties. Of course, the world manager cooperates with the physics component, which performs physical calculations (collision detection, joints solving, fluid buoyancy, and so on) and, possibly, updates the node hierarchy. To put it shortly, the world manager does not draw objects, play sounds, or perform physical calculations on its own. Instead, it delegates these tasks to designated components.初始化后，世界经理开始起作用。它加载构建当前场景所需的文件，并确定可见节点集，然后将其发送到 render 组件。世界经理还告诉声音组件，何时以及如何播放环境声音，哪些声音源放置在世界上某个地方并具有空间特性。当然，世界经理与 physics 组件合作，该组件执行物理计算（碰撞检测，关节解算，流体浮力等），并可能更新节点层次结构。简而言之，世界经理不会自己绘制物体，播放声音或执行物理计算。而是将这些任务委托给指定的组件。

注意

Though it is not typical behavior, the interpreter is also able to wedge in the work of all other components, for example, directly influence the render component.尽管这不是典型的行为，但解释器还可以加入所有其他组件的工作，例如，直接影响渲染组件。

The render and sound components need additional resources to complete their tasks: the render component needs textures, meshes, and animations, and the sound component needs sounds. So, they ask the resource manager to provide them what is required. It is the task of the resource manager to load required graphics and sounds, cache them, and unload if they are no longer required. The presence of the resource manager allows the game developer not to think about how and when the data should be loaded and unloaded.渲染和声音组件需要其他资源才能完成其任务：渲染组件需要纹理，网格和动画，声音组件需要声音。因此，他们要求资源管理器提供所需的信息。资源管理器的任务是加载所需的图形和声音，对其进行缓存，并在不再需要它们时将其卸载。资源管理器的存在使游戏开发人员不必考虑应该如何以及何时加载和卸载数据。

If required by the application logic, the interpreter may also call the GUI component and make it draw the user interface via the render component. In Unigine, GUI objects can be not only stand-alone, but also a part of the displayed virtual world. In the latter case, they are managed by the world manager just like other nodes.如果应用程序逻辑需要，解释器还可以调用 GUI 组件，并使其通过render组件绘制用户界面。在Unigine中，GUI对象不仅可以是独立的，而且可以是显示的虚拟世界的一部分。在后一种情况下，它们由世界经理像其他节点一样进行管理。

When the rendered image, possibly containing the GUI, is displayed, the user, of course, starts interacting with the world. The user can influence the world by means of various input devices. Input from these devices is sent to the GUI component and to the controls component. The GUI component processes the input, detects the clicked element, and executes the corresponding callback function. The controls component processes input that is not related to the GUI, for example the player's actions in the game. Note that the GUI component always gets the input data before the controls component and, therefore, has a higher priority.当显示可能包含GUI的渲染图像时，用户当然会开始与世界互动。用户可以通过各种输入设备来影响世界。这些设备的输入被发送到GUI组件和 controls 组件。 GUI组件处理输入，检测单击的元素并执行相应的回调函数。控件组件处理与GUI不相关的输入，例如游戏中玩家的动作。请注意，GUI组件始终在控件组件之前获取输入数据，因此具有更高的优先级。

The processed input is passed to the interpreter, which detects if the user actions influence render or physics settings, etc. If yes, the interpreter asks the corresponding components to update the image or calculations. If the user input changes something in the world, the world manager updates the set of visible nodes and sends new requests to designated components.处理后的输入传递到解释器，解释器检测用户动作是否影响渲染或物理设置等。如果是，则解释器要求相应的组件更新图像或计算。如果用户输入改变了世界，世界管理器将更新可见节点集并将新请求发送到指定的组件。

These actions are repeated in a cycle, until the user quits the application.循环重复执行这些操作，直到用户退出应用程序为止。