vrm spring bone

[Ander456]

Describe the bug
spring bone data chain only add first child chain; so the other will not be effect

Screenshots, log

UnrealEngine Version:
[UE5.3]

Additional context
for some reason i try to fix the bug use this code replace origin
// // 使用堆栈代替递归处理所有子骨骼
// struct BoneStackItem {
// int32 BoneIndex;
// int32 Depth;
// };
//
// TArray BoneStack;
// for (int32 ChildIndex : Children) {
// BoneStack.Add({ChildIndex, 1});
// }
//
// while (BoneStack.Num() > 0) {
// BoneStackItem CurrentItem = BoneStack.Pop();
// if (CurrentItem.Depth >= 100) {
// continue;
// }
//
// TArray CurrentChildren;
// VRMUtil::GetDirectChildBones(VRMGetRefSkeleton(skeletalMesh), CurrentItem.BoneIndex, CurrentChildren);
// if (CurrentChildren.Num() <= 0)
// {
// continue;
// }
//
// auto& CurrentSData = chain.AddDefaulted_GetRef();
// CurrentSData.boneIndex = CurrentItem.BoneIndex;
// CurrentSData.boneName = *RefSkeleton.GetBoneName(CurrentSData.boneIndex).ToString();
//
// if (CurrentChildren.Num() > 0) {
// CurrentSData.m_boneAxis = RefSkeletonTransform[CurrentChildren[0]].GetLocation();
// } else {
// CurrentSData.m_boneAxis = RefSkeletonTransform[CurrentSData.boneIndex].GetLocation() * 0.7f;
// }
//
// for (int32 ChildIndex : CurrentChildren) {
// BoneStack.Add({ChildIndex, CurrentItem.Depth + 1});
// }
// }
// }
// }

result the strap bone 012 chain is work. but others sway strongly suddenly.

[ruyo]

Hi.
The current VRM4U does not support the branching sway bone.
If you really want to use UE, please change the setting of the sway bone.