I have been using Arnold for a long time.Recent ive been using UE Path Tracing to Render a shot Film,but when i set up AOVs for Nuke.I found out the render time increase by the num of layers.After all Arnold Multi-Layer export will not increas the render time.But UEs Path Tracing render time depend on the layers you separated! Could some one tell me why UE`s Path Tracing take so much time to render in Multi-Layers??