Hello,

I dont really know how to ask the correct questions since i dont know the necessary steps that it takes to convert the given Euler angles from my 3D software to the needed Euler angles in Unreal Engine 4.

I made a plugin for UE4 to spawn instances of Static Mesh Actors into the UE4 level based on a text file which holds the Scale/Rotate/Transform information from the objects in my 3D software scene.

Basically the plugin mirrors the 3D apps objects into UE4.

Everything works but NOT the rotations.

So my question is:

Euler->??->Euler

Thanks!

@Zakwayda

Hello and thanks for your answer.

My 3D software uses XYZ rotation order and Unreal Engine 4 uses XZY rotation order (As far as i could find out so far.)

When i import a 3D model into UE4 then i just set the scaling to 100. Everything else gets corrected already on Import.

Hello, thanks for trying to help me. Much appreciated.

I indeed tryd to negate the rotation angles. In all possible combinations. But it seems to just make the values positive or negative.

I honestly think that it is a Matrix problem of some kind.

Here is the function that gets fed with the 3D-app( Softimage XSI) data.

void SpawnSMActor(const TCHAR *path,float sX,float sY,float sZ,float rX,float rY,float rZ,float pX,float pY,float pZ)
{
    // Load Static Mesh from given Reference Path from UE4 Explorer
    UStaticMesh* StaMesh = LoadObject<UStaticMesh>(nullptr, path);

    // Transform
    FVector objectScale(sX, sY, sZ);        // Scale

    // ************************************************************************************
    // Conversion XSI Coordinate System to UE4 Coordinate System

    FVector NewPosition;
    FRotator NewRotation;

    // We just simply swap the Z and Y Coordinates

    NewPosition.X = pX * 100; //    TX
    NewPosition.Y = pZ * 100; //    TZ
    NewPosition.Z = pY * 100; //    TY

    // We just simply swap the Pitch(Y) and Yaw(Z) angles

    NewRotation.Roll =  rX;     //    RX
    NewRotation.Pitch = -rZ;    //    RZ
    NewRotation.Yaw =   rY;     //    RY

    FRotator NewobjectRotation(NewRotation.Quaternion());

    FTransform objectTransform(NewobjectRotation, NewPosition, objectScale);

    // ************************************************************************************

    // Creating the Actor and Positioning it in the World based on the Static Mesh
    UWorld* currentWorld = GEditor->GetEditorWorldContext().World();
    ULevel* currentLevel = currentWorld->GetCurrentLevel();
    UClass* StaticMeshClass = AStaticMeshActor::StaticClass();
    AActor* NewActorCreated = GEditor->AddActor(currentLevel, StaticMeshClass, objectTransform, true, RF_Public | RF_Standalone | RF_Transactional);
    AStaticMeshActor* smActor = Cast<AStaticMeshActor>(NewActorCreated);

    smActor->GetStaticMeshComponent()->SetStaticMesh(StaMesh);
    smActor->SetActorScale3D(objectScale);

    // ID Name & Visible Name
    //smActor->Rename(TEXT("MyStaticMeshInTheWorld"));
    //smActor->SetActorLabel("MyStaticMeshInTheWorld");

    GEditor->EditorUpdateComponents();
    smActor->GetStaticMeshComponent()->RegisterComponentWithWorld(currentWorld);
    currentWorld->UpdateWorldComponents(true, false);
    smActor->RerunConstructionScripts();
    GLevelEditorModeTools().MapChangeNotify();
}

Hello, thanks for this link!

That gives some interesting insights.

I have tested the rotation order in Softimage, only possible in Local Space.

But that does not matter since in my test scene the object lies anyway in global space. So local and global is the same.

So if i switch the order from XYZ to XZW then i get the "same" values like in UE4.

Here is a new video to proof my point:

Also here is a link that i have found that says (scroll down to the bottom, last post) Maya to UE4 --> XZY.

Maya has the same coordinate system as XSI:

XSI        (Right Handed , Y axis up )
Maya    (Right Handed , Y axis up )

https://answers.unrealengine.com/questions/62077/what-is-the-rotation-order-for-components-or-bones.html

Quaternions are for game engines mostly. Every3D software that i know stores animations in Euler angles and so does XSI.

@JohnnyCode

UE4       (Left Handed    , Z axis up )      
XSI        (Right Handed , Y axis up )
Maya    (Right Handed , Y axis up )