bool FInstancedStaticMeshSCSEditorCustomization::HandleViewportDrag(class USceneComponent* InSceneComponent, class USceneComponent* InComponentTemplate, const FVector& InDeltaTranslation, const FRotator& InDeltaRotation, const FVector& InDeltaScale, const FVector& InPivot)
{
check(InSceneComponent->IsA(UInstancedStaticMeshComponent::StaticClass()));
UInstancedStaticMeshComponent* InstancedStaticMeshComponentScene = CastChecked<UInstancedStaticMeshComponent>(InSceneComponent);
UInstancedStaticMeshComponent* InstancedStaticMeshComponentTemplate = CastChecked<UInstancedStaticMeshComponent>(InComponentTemplate);
// transform pivot into component's space
const FVector LocalPivot = InstancedStaticMeshComponentScene->GetComponentToWorld().InverseTransformPosition(InPivot);
// Ensure that selected instances are up-to-date
ValidateSelectedInstances(InstancedStaticMeshComponentScene);
bool bMovedInstance = false;
check(InstancedStaticMeshComponentScene->SelectedInstances.Num() == InstancedStaticMeshComponentScene->PerInstanceSMData.Num());
for(int32 InstanceIndex = 0; InstanceIndex < InstancedStaticMeshComponentScene->SelectedInstances.Num(); InstanceIndex++)
{
if (InstancedStaticMeshComponentScene->SelectedInstances[InstanceIndex] && InstancedStaticMeshComponentTemplate->PerInstanceSMData.IsValidIndex(InstanceIndex))
{
const FMatrix& MatrixScene = InstancedStaticMeshComponentScene->PerInstanceSMData[InstanceIndex].Transform;
FVector Translation = MatrixScene.GetOrigin();
FRotator Rotation = MatrixScene.Rotator();
FVector Scale = MatrixScene.GetScaleVector();
FVector NewTranslation = Translation;
FRotator NewRotation = Rotation;
FVector NewScale = Scale;
if( !InDeltaRotation.IsZero() )
{
NewRotation = FRotator( InDeltaRotation.Quaternion() * Rotation.Quaternion() );
NewTranslation -= LocalPivot;
NewTranslation = FRotationMatrix( InDeltaRotation ).TransformPosition( NewTranslation );
NewTranslation += LocalPivot;
}
NewTranslation += InDeltaTranslation;
if( !InDeltaScale.IsNearlyZero() )
{
const FScaleMatrix ScaleMatrix( InDeltaScale );
FVector DeltaScale3D = ScaleMatrix.TransformPosition( Scale );
NewScale = Scale + DeltaScale3D;
NewTranslation -= LocalPivot;
NewTranslation += ScaleMatrix.TransformPosition( NewTranslation );
NewTranslation += LocalPivot;
}
InstancedStaticMeshComponentScene->UpdateInstanceTransform(InstanceIndex, FTransform(NewRotation, NewTranslation, NewScale));
InstancedStaticMeshComponentTemplate->UpdateInstanceTransform(InstanceIndex, FTransform(NewRotation, NewTranslation, NewScale));
bMovedInstance = true;
}
}
return bMovedInstance;
}
