Quote - Hm, popped back into this thread and notice BB talking about Diffuse Value properly being 75-80%, which is something I didn't know. I'm sure Bagginsbill has posted at length on this somewhere... can someone point me to a good discussion of the principles involved?

i can't seem to find it now, but there's a thread on CGTalk about the basic principles of textures and materials.  i could have sworn it was a sticky.  anyway, it gets into how nothing is purely diffuse or purely reflective.  there's a range.  basically, if i understand it right, your total should be about 1 when combining your lighting effects.  because your object isn't creating light unless it's glowing.

i remember the CGTalk thread saying skin was between .7 something and .8 something diffuse value.  personally, one of the first things i discovered with shaders (before VSS and before GC discussions) was that they became much more realistic when you let your diffuse and specular values have a sum with in a decent range of 1.  i suppose this also means that if you have a specular map controlling your specular amount, you should probably use an inverted version controlling your diffuse amount.

iirc, default materials have 1.0 diffuse value and 1.0 specular value.  one reason that looks so fake is that relationship is way off.  and the closer your lighting gets to reality, the more realistic you need to be about conservation of energy with your materials.