It's not unusual to use direct light source / sun in addition with hdri map, since most of hdri's comes without fully captured sun's intensity (i'm not talking about hdri's where sun is rising/ setting or is occluded by thick layer of clouds). But i see no point to lock them together.
I see, maybe I'm wrong. I'd meant you didn't used the HDRI in environment slot. Just simple used for the background map, and then if you locked the Sun position for the background (HDRI) and rotating the Sun, than rotating the background too...
I seen this technic in the Evermotion Arcviz 2, and this is a really good stuff to changeing together the Sun direction and the background map...And than it's dosn't matter do you have or not the Sun on the map or maybe cloudy. No chance to make 2 Sun (light) directions...But if you have a cloudy map, than you have fixing the Sun's setup for the picture...
Do you understand me what I tried to writing here? :)
You know...my selfthought englissshhh... ;D
