Introduction to UE gameplay 44 (animation import FBX and production standard)

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#1. UE Animation resources that can be created in

Aim Offset： Aim Offset , be used for FPS Game guns
Aim Offset 1D： Aim Offset , be used for 2d Game FPS Game firearms
Animation Blueprint： Animation blueprint , Control the execution logic of animation , The animation blueprint acts on the skeleton mesh body , In operation, the general process is Character->Animation BP->Montage->Animation Clip
Animation Composite： Combination animation , Used to group multiple animations , Like multiple Idle Animation
Animation Layer Interface： Animation level interface , Separate complex animation to all levels , The interface can be implemented in the animation blueprint , Link multiple animation blueprints
Animation Montage： Montage animation ,UE Very easy to use animation function in , Can be integrated into events 、 Sound effect 、 Special effects
Animation Sharing Setup： Sharing animation can reduce the number of people Actor The amount of animation work required , Use in some settings , For example, cluster AI, When making videos , You don't need to animate it alone
Blend Space： Animation blending space ,UE Animation blending in , After mixing, it is also an animation （ Animation with parameters ）
Blend Space 1D：2d The animation mixing space of the game
Bone Compression Settings： Animate bone compression settings ,UE An animation optimization function of
Curve Compression Settings： Animation bone compression curve settings
Camera Animation Sequence： Camera animation sequence , Specially control the camera's animation
Level Sequence： Level crossing animation sequence
Template Sequence： Temporary cut animation sequence , Embedded animation sequence
Paper Flipbook：UE Medium 2d Animation
Pose Asset： Animation T-Pose or A-Pose assets , Generally used as animation redirection

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#2. FBX Import and related resources
When importing , If it is pure Mesh Resources are also bound with a skeleton ,UE Will be identified as a skeleton grid asset

stay 3d In the process of making the software ,Mesh It is pulled out by modeling , A skeleton is a resource that is bound after modeling , Recorded Mesh Associated motion information , This information will be accompanied by FBX Together , Import to UE Will be separated automatically ,Unity It's called in Chinese Avator（ double ）

#. Import options

A total of 6 Large type
#1. Mesh（ As Skeletal Mesh)

Skeletal Mesh： Whether it is a skeleton mesh body
Import Mesh： Whether to import mesh body , Or just import the skeleton ,UE Really subdivide
Import Content Type： Import type , Mesh geometry and skin weights 、 Mesh geometry 、 Skin Weights
Skeleton： Skeleton resources , Select existing or auto generated （FBX extract ）
Vertex Color Import Option： Mesh vertex color import options , Use Mesh Vertex color or UE Default vertex color
Vertex Override Color： The vertex color of the overlay
Update Skeleton Reference Pose： Update the reference posture of the skeleton , The general skeleton is T-Pose or A-Pose, If the selected skeleton has Retarget too ,
When importing animation again , No need to... Again Retarget, You can update the posture directly
Use T0 As Ref Pose： Use the first frame of the animation track （ frame 0） Of Retarget The posture of resources
Preserve Smoothing Groups： If enabled , Triangles with mismatched smoothing groups will be physically split , Copy shared vertices
Import Meshes in Bone Hierarchy： If enabled , Mesh bodies embedded in the bone level will be imported , Instead of converting to bones
Import Morph Targets： Import deformation animation
Import Mesh LODs： Import custom mesh LOD
Normal Import Method： Normal import method ,UE Calculating normals , Import normals or import normals and tangents
Normal Generation Method： Normal generation method ,Mikk TSpace Or built-in
Compute Weighted Normal： Calculate normal weights
Thresholds： Calculation error , Including the position of the net body 、 Normal tangent 、UV、 Deformation animation
Create Physics Asset： Whether to create physical assets , Or select an existing physical asset
Physics Asset： Select an existing physical asset

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#1. Mesh（ As Static Mesh)

When put Skeletal Mesh After removal , By default, only... Will be imported Static Mesh;Static Mesh and Skeletal Mesh The options vary a lot
Static Mesh： Static mesh bodies for building scenes , Statically related world objects
Skeletal Mesh： Skeleton mesh bodies are used for animated models , Use the skeleton to drive

Generate Missing Collision： Generate default collisions for mesh bodies , What is generated is a simple collision
Static Mesh LODGroup： Import the default of static mesh LOD Group
Vertex Color Import Option： Model default vertex color import options , Same as Skeletal Mesh
Vertex Override Color： Vertex color overlay
Remove Degenerates： Remove degradation , Remove degenerated triangles when importing
Build Adjacency Buffer： Build adjacency buffer , Whether to use PN Surface optimization
Build Reversed Index Buffer： Build a reverse index buffer , Reduce the... Between drawing calls GPU Number of status changes
Generate Lightmap UVs： Whether to generate lightmaps , Static lighting
One Convex Hull Per UCX： Every UCX A convex hull , Force all UCX The mesh body receives a convex hull
Combine Meshes： Will import all Mesh To form a Mesh
Transform Vertex to Absolute：FBX The file will use transformations for the world scene origin 、 Offset and pivot or use Mesh The center of
Bake Pivot in Vertex： Pivot rotation is applied to the mesh body
Import Mesh LODs： Whether to import Mesh Of LOD Set up
Normal Import Method： How to import normals , Same as Skeletal Mesh
Normal Generation Method： How normals are generated , Same as SkeletalMesh
Compute Weighted Normal： Calculate normal weights , Same as Skeletal Mesh

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#1. Mesh（ As slice animation ）

When importing slice animation, you need to specify a skeleton

Mesh、Skeletal、Animation yes 3d Resources exported during software production , this 3 Resources are just packaged in one fbx in , Various functions and operations are independent

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#2. Animation（Skeletal Mesh Or slice animation import ）

Animation Length： Import animation duration , Export time 、 Animation time 、 Range time （ A range can be set ）
Frame Import Range： Import the range of animation
Import Meshes in Bone Hierarchy： If checked, , Mesh bodies embedded in the bone level will be imported , Instead of converting to bones
Use Default Sample Rate： Use the default 30 Frame animation or use the frame rate of the animation itself
Custom Sample Rate： Custom animation frame rate ,0 when , The optimal sampling rate will be determined automatically
Import Custom Attribute： Import animation curves
Delete Existing Custom Attribute Curve： Delete existing animation curves , When re importing
Delete Existing Non Curve Custom： Delete existing non custom curves , When re importing
Import Bone Tracks： Import bone tracks , For curve animation
Set Material Curve Type： Whether to set the material curve animation type , Animation controls material changes
Material Curve Suffixes： Material curve prefix name
Remove Redundant Keys： When importing custom attributes as curves , Redundant keys will be removed
Delete Existing Morph Target Curve： Delete the existing deformation target （ expression ）, When re importing
Do not import curves with only 0 values： Do not import 0 Value curve
Preserve Local Transform： Whether to maintain the local transformation of the animation ,UE Calculate the global transformation , Then back to the local transformation

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#3. Transform Import model transformations

Import Translation： Import transform position
Import Rotation： Import transform rotation
Import Uniform Scale： Import uniform zoom

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#4. Miscellaneous（ miscellaneous ）

Convert Scene： Change the scene from FBX Coordinate system conversion to use UE4 The coordinate system of
Force Front XAxis： Change the scene from FBX Coordinate system conversion to before use X Axis instead of Y The shaft UE4 Coordinate system
Convert Scene Unit： Change the scene from FBX The UOM is converted to UE4 Unit of measurement , Cm
Override Full Name： Use string " name （Name）" Field as the full name of the grid body

I am using Unity Model import UE When , Find that the model becomes very small , because UE The use of cm, and Unity It uses m, When importing
Need to transform m To cm, Then the model will display the normal size
then Force Front XAxis It's also very easy to use , same Mesh Space coordinate system to UE World order of the world , It is convenient to calculate and use in the future

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#5. Material（ Only when importing animation, there is no material option ）

Search Location： Material find location , Don't find 、 Current directory 、 Parent directory 、 Follow directory 、 All resources 5 An option
Material Import Method： Material import method , Do not create materials , Create materials and create material instances
Import Texture： Whether to import texture
Invert Normal Maps： Reverse normal mapping
Reorder Material to Fbx Order： according to FBX Order readjust the material order

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#6. fbx file information

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#6. The official recommendation is to set

fbx Import FAQ
#1. Smooth group alarm , You can ignore ,FBX scene=FBX,scene Express Mesh Local space

No smoothing group information was found in this FBX scene. Please make sure to enable the ‘Export Smoothing Groups’ option in the FBX Exporter plug-in before exporting the file. Even for tools that don’t support smoothing groups, the FBX Exporter will generate appropriate smoothing data at export-time so that correct vertex normals can be inferred while importing.

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Reference material ：
https://docs.unrealengine.com/4.27/zh-CN/WorkingWithContent/Importing/FBX/ImportOptions/

https://docs.unrealengine.com/4.27/zh-CN/WorkingWithContent/Importing/FBX/HowTo/

https://docs.unrealengine.com/4.27/zh-CN/WorkingWithContent/Importing/FBX/ContentStandards/

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