请教有关UE4导入BVH文件的问题

Question

我最近在研究有关BVH文件导入UE4并且还原动作数据的功能，BVH文件是从MotionBuilder中导出的，我在UE4动画蓝图中利用C++自定义了一个动画节点，并每帧对将BVH数据赋值到骨骼点上，但是胳膊、腿总是还原的不正确。MotionBuilder是右手坐标系，Y轴朝上，Z轴朝外，我经过如下空间转换。请教各位请问是哪个环节出了问题？万分感谢！

```c++
void FAnimNode_PlayBVH::EvaluateComponentSpace_AnyThread(FComponentSpacePoseContext& Output)
{
    BasePose.EvaluateComponentSpace(Output);

    Output.ResetToRefPose();
    check(Output.AnimInstanceProxy->GetSkeleton() != nullptr);

    const FBoneContainer& BoneContainer = Output.Pose.GetPose().GetBoneContainer();
    FTransform ComponentTransform = Output.AnimInstanceProxy->GetComponentTransform();
    for (int32 i = 0; i < FrameData.Num(); i++)
    {
        GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, FString::Printf(TEXT("BoneName: %s"), *FrameData[i].BoneName.ToString()));
        int32 index = BoneContainer.GetPoseBoneIndexForBoneName(FrameData[i].BoneName);

        if (index != -1)
        {

            FCompactPoseBoneIndex CompactPoseBoneToModify(index);
            FTransform NewBoneTM = Output.Pose.GetComponentSpaceTransform(CompactPoseBoneToModify);

            //Convert to Bone Space.
            if (FrameData[i].TranslationMode == VF_Additive)
            {
                //Convert to Bone Space.
                FAnimationRuntime::ConvertCSTransformToBoneSpace(ComponentTransform, Output.Pose, NewBoneTM, CompactPoseBoneToModify, BCS_ComponentSpace);
                NewBoneTM.SetTranslation(FrameData[i].bvhPos);
                //Convert back to Component Space.
                FAnimationRuntime::ConvertBoneSpaceTransformToCS(ComponentTransform, Output.Pose, NewBoneTM, CompactPoseBoneToModify, BCS_ComponentSpace);

            }

            FAnimationRuntime::ConvertCSTransformToBoneSpace(ComponentTransform, Output.Pose, NewBoneTM, CompactPoseBoneToModify, BCS_ComponentSpace);
            
            FQuat qx(FVector(1, 0, 0), -FMath::DegreesToRadians(FrameData[i].Xrotation));
            FQuat qz(FVector(0, 0, 1), -FMath::DegreesToRadians(FrameData[i].Yrotation));
            FQuat qy(FVector(0, 1, 0), -FMath::DegreesToRadians(FrameData[i].Zrotation));
            
            FQuat qu = qy * qz * qx;    
            
            NewBoneTM.SetRotation(qu * NewBoneTM.GetRotation());    
            
            //Convert back to Component Space.
            FAnimationRuntime::ConvertBoneSpaceTransformToCS(ComponentTransform, Output.Pose, NewBoneTM, CompactPoseBoneToModify, BCS_ComponentSpace);
            
            Output.Pose.SetComponentSpaceTransform(CompactPoseBoneToModify, NewBoneTM);
        }
    }
}