void FFbxExporter::ExportAnimSequenceToFbx(const UAnimSequence* AnimSeq,
const USkeletalMesh* SkelMesh,
TArray<FbxNode*>& BoneNodes,
FbxAnimLayer* InAnimLayer,
float AnimStartOffset,
float AnimEndOffset,
float AnimPlayRate,
float StartTime)
{
USkeleton* Skeleton = AnimSeq->GetSkeleton();
if (AnimSeq->SequenceLength == 0.f)
{
// something is wrong
return;
}
const float FrameRate = AnimSeq->NumFrames / AnimSeq->SequenceLength;
// set time correctly
FbxTime ExportedStartTime, ExportedStopTime;
if ( FMath::IsNearlyEqual(FrameRate, DEFAULT_SAMPLERATE, 1.f) )
{
ExportedStartTime.SetGlobalTimeMode(FbxTime::eFrames30);
ExportedStopTime.SetGlobalTimeMode(FbxTime::eFrames30);
}
else
{
ExportedStartTime.SetGlobalTimeMode(FbxTime::eCustom, FrameRate);
ExportedStopTime.SetGlobalTimeMode(FbxTime::eCustom, FrameRate);
}
ExportedStartTime.SetSecondDouble(0.f);
ExportedStopTime.SetSecondDouble(AnimSeq->SequenceLength);
FbxTimeSpan ExportedTimeSpan;
ExportedTimeSpan.Set(ExportedStartTime, ExportedStopTime);
AnimStack->SetLocalTimeSpan(ExportedTimeSpan);
// Add the animation data to the bone nodes
for(int32 BoneIndex = 0; BoneIndex < BoneNodes.Num(); ++BoneIndex)
{
FbxNode* CurrentBoneNode = BoneNodes[BoneIndex];
// Create the AnimCurves
FbxAnimCurve* Curves[6];
Curves[0] = CurrentBoneNode->LclTranslation.GetCurve(InAnimLayer, FBXSDK_CURVENODE_COMPONENT_X, true);
Curves[1] = CurrentBoneNode->LclTranslation.GetCurve(InAnimLayer, FBXSDK_CURVENODE_COMPONENT_Y, true);
Curves[2] = CurrentBoneNode->LclTranslation.GetCurve(InAnimLayer, FBXSDK_CURVENODE_COMPONENT_Z, true);
Curves[3] = CurrentBoneNode->LclRotation.GetCurve(InAnimLayer, FBXSDK_CURVENODE_COMPONENT_X, true);
Curves[4] = CurrentBoneNode->LclRotation.GetCurve(InAnimLayer, FBXSDK_CURVENODE_COMPONENT_Y, true);
Curves[5] = CurrentBoneNode->LclRotation.GetCurve(InAnimLayer, FBXSDK_CURVENODE_COMPONENT_Z, true);
float AnimTime = AnimStartOffset;
float AnimEndTime = (AnimSeq->SequenceLength - AnimEndOffset);
// Subtracts 1 because NumFrames includes an initial pose for 0.0 second
double TimePerKey = (AnimSeq->SequenceLength / (AnimSeq->NumFrames-1));
const float AnimTimeIncrement = TimePerKey * AnimPlayRate;
FbxTime ExportTime;
ExportTime.SetSecondDouble(StartTime);
FbxTime ExportTimeIncrement;
ExportTimeIncrement.SetSecondDouble( TimePerKey );
int32 BoneTreeIndex = Skeleton->GetSkeletonBoneIndexFromMeshBoneIndex(SkelMesh, BoneIndex);
int32 BoneTrackIndex = Skeleton->GetAnimationTrackIndex(BoneTreeIndex, AnimSeq);
if(BoneTrackIndex == INDEX_NONE)
{
// If this sequence does not have a track for the current bone, then skip it
continue;
}
for(int32 i = 0; i < 6; ++i)
{
Curves[i]->KeyModifyBegin();
}
bool bLastKey = false;
// Step through each frame and add the bone's transformation data
while (!bLastKey)
{
FTransform BoneAtom;
AnimSeq->GetBoneTransform(BoneAtom, BoneTrackIndex, AnimTime, true);
FbxVector4 Translation = Converter.ConvertToFbxPos(BoneAtom.GetTranslation());
FbxVector4 Rotation = Converter.ConvertToFbxRot(BoneAtom.GetRotation().Euler());
int32 lKeyIndex;
bLastKey = AnimTime >= AnimEndTime;
for(int32 i = 0, j=3; i < 3; ++i, ++j)
{
lKeyIndex = Curves[i]->KeyAdd(ExportTime);
Curves[i]->KeySetValue(lKeyIndex, Translation[i]);
Curves[i]->KeySetInterpolation(lKeyIndex, bLastKey ? FbxAnimCurveDef::eInterpolationConstant : FbxAnimCurveDef::eInterpolationCubic);
if( bLastKey )
{
Curves[i]->KeySetConstantMode( lKeyIndex, FbxAnimCurveDef::eConstantStandard );
}
lKeyIndex = Curves[j]->KeyAdd(ExportTime);
Curves[j]->KeySetValue(lKeyIndex, Rotation[i]);
Curves[j]->KeySetInterpolation(lKeyIndex, bLastKey ? FbxAnimCurveDef::eInterpolationConstant : FbxAnimCurveDef::eInterpolationCubic);
if( bLastKey )
{
Curves[j]->KeySetConstantMode( lKeyIndex, FbxAnimCurveDef::eConstantStandard );
}
}
ExportTime += ExportTimeIncrement;
AnimTime += AnimTimeIncrement;
}
for(int32 i = 0; i < 6; ++i)
{
Curves[i]->KeyModifyEnd();
}
}
}
