I did not understand what blend meant in this context and what adding a irradian cube within anotherone with a value of 2, 2, 2 was accomplishing?
edit: I dont understand of the advantage of baking numberouce radiance cubes with different values on top of each other and why you would not just use one box with a higher number of probes then bake and not need to add more cubes.
Why not just use one irradiance cube with more probes and get the same amount of probes you would from stacking multiple irradiance volumes? What is teh advantage of using multiple volumes on top of each other instead of using one volume with just more probes in it?
The last lesson in this chapter, Lighting a Bedroom with Eevee, will help you understand the use of multiple irradiance cubes. Using them to illuminate areas of the scene.
Because of the difference of how light behaviour, in particular bounce light, is calculated between Cycles and Eevee, we can use irradiance cubes to help create more realistic lighting with Eevee.
Think of each probe as taking a reading of available light at each probe location. By adding one big cube, as Spikey said, you will have probes inside objects. This can effect the light, and shadow, around the object. Depending on how close the probes are, and you definitely don't want probes intersecting the surface of objects.
