I am doing a product rendering for a client. Everything should be in real word measurements, or real world scale.
I know that I can set blender to units and accomplish the measurements.
But what about rendering in cycles, specially AO, SSS etc.
Does measurement matter in case of cycles?
f.e.: if the scene is very large in Octane render (or very small), you need to set AO to ensure that rendering is correct.
World scale is important when doing physics sims in either engine, where 1BU = 1m is the baseline scale iirc. Some sims have a scalling capability, but not all.
In Cycles, I would think that world scale can affect lighting results, if the coded parameters for lighting are based on a certain assumed world scale. For example, the inverse square law for light fall-off will depend on the scale of a scene, unless there is a way to compensate in the settings. The Scale factor in the SSS node is also dependent on model scale afaik. There may be other physics-dependent parameters and nodes that will be affected by a choice of world scale.