[UE4]FBX Export and Import Related

Keywords: Multiple roots found

Attentions

Skinning Method

UE4 doesn’t support Dual Quaternion of Maya, Skinning Method must be set as Classic Linear.

Import SkeletalMesh using existed Skeleton

Check Skeletal Mesh and select existed Skeleton.

When pop a tip window ask if regenerate Skeleton, click Yes.

Issues

Duplicate bone name found (‘XXX’). Each bone must have a unique name

Issue:
When Import FBX into UE4, there’s error log:

Multiple roots found 
Error, Could not import MinigunPlaceholderSkel.
Duplicate bone name found ('MinigunPlaceholderSkel'). Each bone must have a unique name. 

Possible Causes:

• The Group name is the same as the Mesh name or Bone name.

  

• There’s no Group out of Mesh and Bones.

Solution:

• Change Group name that isn’t the same as Mesh name or Bone name.
• Create a Group and put Mesh and Bone under it.

  

Mesh contains XXXX bone as root but animation doesn’t contain the root track

Error on importing animation asset (FBX):

FBXImport: Error: Mesh contains XXXX bone as root but animation doesn't contain the root track.
Import failed.
FBXImport: Error: Import failed.

Caused by:
The name of top node in Outliner (the top node can be a Joint, or a Group) wasn’t the same between skeletal mesh and animation sequence.

Solution:
Make sure the name of top node in both skeletal mesh and animation sequence are the same.
Group name in skeletal mesh:

When names of top node are the same, then you can name the chind node as what you want. e.g. you can name the child node which under root node as AAAA

Seams on mesh (small piece deleted)

Uncheck Remove Degenerates:

这世上所有事都不能感同身受，只能报以温柔。