The basic understanding of the unity3d of the game world

1. Write in front

Unity3d is a fully integrated, professional game engine developed by Unity Technologies, a multi-platform, integrated game development tool that lets you easily create interactive content such as three-dimensional video games, architectural visualizations, real-time three-dimensional animations, and more. Unity is similar to Director,blender game engine, virtools or Torque game builder, and other software whose editor runs under Windows and Mac OS x with interactive, graphical development environments as the primary means. You can publish games to Windows, Mac, Wii, IPhone, Windows Phone 8, and Android platforms. You can also use the Unity Web Player plugin to publish Web games that support Web browsing for Mac and Windows. Its web player is also supported by Mac widgets.

Unity3d, abbreviated as U3D, is a mid-end game engine developed by the German unitytechnologies company.
U3d compared to Unreal 3 engine, can only be a small-brother game engine, but its high efficiency in game production, as well as the corresponding multi-platform game development, making it in foreign independent game production team has a high popularity.

U3d's free version and professional version of the difference is mainly in the screen filter and the use of the underlying class library permissions, u3d free version is able to make a full game, and can publish Pc,mac and web platform games, mobile platform (ios,android) and the next Generation Game console platform (ps3,xbox360 , the WII) requires additional authorization.
*unity3d's development company, in collaboration with Adobe, has increased the release capabilities of Flash from the 3.5 release (additional authorization required).

U3d from the Unreal engine and some large three-dimensional animation software operating concepts, it is easy to get started, and it and other software collaboration will be very convenient. U3D's software interface layout is perfect, the user can quickly choose a suitable for their own development habits of the window sorting.

* If you want to compare with the three-dimensional animation software, I think u3d is like Maya software operation, 3dsMax function execution, c4d menu management. when creating a new project catalog, U3D does not load the resource bundle by default in order to increase the loading speed of the scene. Therefore, the user can choose the corresponding function package according to their own engineering needs. Examples include built-in character control systems, terrain components, sky boxes, screen filters, script sets, and more. U3d's Engineering directory, as a system folder for resource storage, can be updated and invoked at any time, and the u3d is more user-friendly than the UDK must be imported into the engine package in advance. We can create folders directly in U3d's Project Catalog Management window to store and classify resources such as scripts (script), materials (material), meshes (grid), scenes (scene), textures (map), etc. u3d files are automatically arranged, in order to maintain our established directory order, we can add an underscore before the file name, such as: _ Script,_material. U3d can build some basic geometry, but you can't perform modeling operations, only make some simple overall transformations on them, so most of the graphical elements we need to import from outside. Although the terrain can be created and plotted in u3d, it would be more desirable to use Maya to create a terrain that is not very flat, as it relates to the problem of map stretching.
* U3D Currently cannot change the pivot point of the model, so it needs to be set up in the three-dimensional software beforehand. U3d's scene units are meters, and Maya is centimeters, so the software's value on Maya needs to be set to 100 times times to match the scene proportions in the engine. For example, a 1.7M high role in an engine, the height in Maya should be 170 units (cm)--you can also set the unit when you export the Fbx file, or adjust the Scalefactor property of the Fbx file in U3d. Of course, users can also change the default Maya units themselves, but it is not recommended by individuals, because in addition to the dynamics, some of the default values for modeling will become huge (for example, bevel chamfer).
*u3d Although the unit is meters, but its default scalefactor parameter is 0.01, that is, the corresponding is Maya in centimeters, if you are using meters in Maya, when you import u3d, you also need to manually set the Scalefactor to 1. Although u3d supports importing Maya-specific ma,mb or 3dsMax max format files, reads are slow, so the external import 3D file format that is best suited for u3d is FBX. When the fbx file is placed in the U3D project directory, U3d automatically reads the model material contained in the FBX and is attributed to a separate folder materials. Note that dragging the map to the material ball in the u3d and clicking the Select button in the Material sphere map box is not the same, the former will constantly generate independent textures to increase the amount of files, while the latter is a common texture.
*u3d3. X is also not able to give the same material to multiple objects at the same time, so before importing u3d, we should classify the material in Maya, and also pay attention to the normal orientation of the model face and try not to show the opposite side. tip: After the unity4.x version, you can assign materials to multiple objects at once. when the prefabs is placed in the scene, it will automatically form a Maya rendering agent-like geometry, modify the properties of this geometry, click Revert can return to the initial state, if you click Apply, will be applied directly to the project catalog prefabs, Prefabs in all scenarios will change at the same time, so use caution.

Skybox The creation of the sky box. The sky in the game is the geometric thoughtfulness of a parcel scene. For the game engine, there are six seamless sky textures that cover six facets of a cube. The U3d Sky box needs to be associated with the camera or in the render settings.
* Add sky material to the rendering settings, you can see the effect directly in the scene, the camera is connected to the Sky box, only when the game rendering is performed, it will be seen in the specific camera.

There are four types of lights in U3d: Pointlight,spotlight,directionallight,arealight,ambientlight. The ambientlight is not an independent light element, but is located in the render settings, which can be used to color-adjust the backlight in the scene (usually a cold color) to simulate ambient reflection light (mostly skylight). Directional light is often used to simulate sunlight, where the light does not affect the lighting effect because it is based on orientation.

Currently, the u3d lighting system and scene building elements are not as rich as the UDK (Unreal Engine Development kit), so the graphics rendering is naturally not as good as the UDK, but it is enough to develop a powerful next-generation game, with mobile platforms and online games.

Renderpass Render channel. There are three important rendering channels in the U3d, which are based on the light material. Currently, U3D has not implemented a texture-animated connection like Maya or UDK, so users need to write their own materials, which limits their creativity to a certain extent.

Lightmass Quality setting directly determines the quality of the game. The lights and shadows in the scene are calculated in real time, which is not applied to the game, and the game uses light maps and shadow maps to improve the efficiency of the screen. For stationary objects in the scene, we can use a variety of global illumination to bake the light effect to the map corresponding to the model, there are two ways: one is to paint the model map, through the three-dimensional software of the global light system (such as FG final aggregation, GI global illumination), the lighting effect baked In addition, it is baked directly in the game engine (depending on the function of the engine). U3D's lighting system is not as powerful as the UDK, especially in the global lighting.

Occlusionculling is a feature used in u3d to optimize the efficiency of scene display, which can greatly reduce the consumption of the system resources of the game. The principle is not to draw obscured objects that are not visible in the camera range.
*u3d can do a lot of resource optimization for web and mobile platforms, which is not a good thing for UDK.

U3D supports scripting in multiple languages: C#,javascript,boo. JavaScript scripts are easy to use, often as the first choice for beginners or JavaScript programmers, but in the long run, C # is the user's best choice. Of course, you can also combine scripts in several languages during a game design process, because u3d eventually converts these languages into its built-in compilation language.
*javascript is not java.

"Summary"

Unity3d has broad prospects for development: Universal software operating standards, efficient development speed, multi-platform support, and compatibility with a wide range of programming languages.

The basic understanding of the unity3d of the game world