The animation is correct (have even reset the rotation of the bottom bone of the upper arm where the distortion is and in blender it looks smooth, but on import into UE there are distortions.
I’ve limited the bone influences to 8, set smoothing to face in blender and even without showing any warnings the mesh does look worse in UE than in blender.
Is it possible that UE is truncating some bone influences on import in the background without even giving a warning about it or is it some rounding issue? I’ve got a high resolution mesh and need precise bone weight values for most realistic look of my character.
And if it is a problem with some shader calculations / rounding of values, where in the source code can I find that part and hopefully correct it?