Briefly describe the model animation function of unity

Understanding and simple use unity Model animation function of , And plug-ins . With FBX And Generic Type of bone skin animation is the main narration .

The official link ：  Model - Unity manual

3D Resource file - Model and animation
Basic concepts

First , We need to know ,3d In the game , When we talk about a model animation , There are two parts , One is the model , One is animation , All come from .fbx Format file , Or other supported format files ： Model file format - Unity manual . This article is based on .fbx The format file is narration .

The basic composition of the model is the grid ： grid - Unity manual . A mesh is a triangle of vertices , Then, the data set of the whole visible appearance is composed of triangles . A model can contain multiple such sets . For example, people. , if necessary , We can put the body 、 Limbs 、 The heads are split into separate grids , And form a unified .fbx file . Of course , If not necessary , Try not to split so many meshes .

Reference , You can learn more about related concepts , You can skip directly when getting started , It is all possible to dissuade ：

Wikipedia ：https://en.wikipedia.org/wiki/FBX
Official website FBX Of SDK, There is a clear code data structure ：Help
Customize FBX Two level system reader ：FBX binary file format specification — Blender Developers Blog
There is a good parsing process ： Deep understanding of loading FBX Model file _ Ocean personal blog -CSDN Blog _fbx file
There is a good principle introduction ： Introduction to the principle of bone animation program _ Zhao's blog -CSDN Blog _ Skeletal animation
 

https://en.wikipedia.org/wiki/FBX

FBX binary file format specification — Blender Developers Blog

Introduction to the principle of bone animation program _ Zhao a 3D The blog of -CSDN Blog _ The principle of bone animation

Deep understanding of loading FBX Model file _ ocean _ The blog of -CSDN Blog _fbx File parsing

Common division and naming methods of resources

        Usually , We will export the model data file into a separate file .fbx, Other animation files are also exported as independent .fbx. According to model_name.fbx and [email protected]_name.fbx The form of naming , Then the animation .fbx The file will automatically generate a built-in animation_name.anim Animation clip components , For follow-up Animator Components use . These concepts will be mentioned later .
 

Model and animation types

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Unity Model type
  Basic concepts and usage scenarios

 

        from Unity In terms of , There are three types of model animation, namely Legacy、Generic、Humanoid.Legacy Basically abandoned , What we use more is Generic and Humanoid. From the perspective of program, model animation is ： Vertex animation 、 Skin, bone, animation, etc .

Unity Generic And Humanoid Some basic points of de blindness ：

Humanoid The use scope of the type is the same as Generic The scope of type use is equivalent , But the internal implementation is different , That is to say, use Generic What can be achieved ,Humanoid Can basically achieve . however Unity Yes Humanoid Do more encapsulation of upper layer applications .
Generic Meet the general animation needs , and Humanoid Type combination Unity Of Avartar have access to Unity Built in IK、AvartarMask、 Redirection and other functions （ This is because many colleagues started learning based on business engines , Mistakenly Avartar Such definitions are conceptually related to 3D The model animation is bound together , Remove the blindness here ）.
Humanoid Performance consumption of >Generic. General model animation playback , Use Generic It can also meet the requirements , Even human form model animation .
Several common programs and animation types in the sense of art ：

Skinned Mesh （SkinnedMesh）： Analogy to ： Like human movement, bones drive the skin . An overview is , Driven by the world matrix , The root bone matrix drives the child bones , Drive the whole body bones layer by layer , Then determine the weight influence of each bone on each vertex on the object model mesh through the skin information , Finally determine the actual operation position of each vertex on the object . This article blog It's clear , Want to continue to understand , You can find someone special 3D Knowledge learning ： Introduction to the principle of bone animation program _ Zhao a 3D The blog of -CSDN Blog _ The principle of bone animation

Blend shape animation （BlendShape）： This is different from bone animation , It consists of the same mesh at most , Predefine different mesh shapes , Perform interpolation , Instead of passing it in through the bones , Reference resources ：Unity Project face pinching solution BlendShape_ Tianfu'er's blog -CSDN Blog _unity Pinch your face
Vertex animation ： stay Unity There is little direct contact with vertex animation in , Vertex animation is similar to blend animation , However, it records all vertex data of each frame , Frame by frame to play . This model for large vertex numbers , Will occupy a considerable amount of memory , But there's no computational pressure . In some animation solutions , There will be bake Functions of baking animation , In fact, it is to convert the calculation results of each frame of bone animation into vertex animation , recorded . Due to less use , I'll just mention .

https://blog.csdn.net/zhousanxi123/article/details/122959094