I have several rooms in the scene. How best to use LightmassImportanceVolume and PostProcessVolume? I mean one in every room or one common to all?
And is this really necessary to Lights (Direction Light, Skylight, etc.) are within those boxes?
In most cases you need only one lightmass importance volume covering all of the lights and meshes, and yes, all the lights must be inside the volume. Post process volume depends on the project. If you need more than one you set the main post process volume as Unbound and the others scaled enough to cover the room it will affect.
Do I understand correctly? I can create one big LightmassImportanceVolume box, after that creare some PostProcessVolume boxes, and these last boxes will cross LightmassImportanceVolume box in some areas.
For example if I wand different effect in separate rooms.
Not quite. Lightmass importance volume and post process volume are two different things used for different purposes. Lightmass importance volume is used to define the area to build the lights for with the highest quality in the shortest time. Post process volume is used to adjust post effects like lens flare, bloom, ambient occlusion. So, you need one lightmass importance volume covering the level, and one post process volume set to unbound(unbound makes it global so its size doesn’t matter) unless you want different effects for each room.
Оk… i create one little the main post process volume as Unbound, and another one for one room to do different effects?
I would test it.
Sorry for my english.