Hi Guys
Havent been around here for a lonnggg while…no excuses really.
The reason Im back is the vain hope that someone may have gone down this route, and can offer some advice. The mental images forum is useless…dont think the max part sees anything more comlpicated than ‘help my FG is blotchy’
Im basically trying to unwrap Fast SSS, and get render layers out for all those elements:
Deep Scatter
Subdermal
Epidermal
Specular
Reflection.
This is the route I have gone…
Build a MR shader with a composite map, and a Fast SSS in each, screened to achieve the desired result. From here I realised that MR lable material element doesnt do squat…so I started to use Mega_TK. This works well, but…SSS doesnt work in shellac or composite. SO I unlocked the lightmap write, and got this working…
After making all my composite inputs, Mega_TK materials, then a shader to material, then the Fast SSS elements it is working well. The final RGB beauty pass looks just like full material.
See material:
So far so good. Now the main issue is that Mega_TK doesnt seem to like the composite map. I have all the nodes placed into the special channels, and it only spits out the top most layer, ignoring the layers below. So from outputting the 8 special TK layers, 7 are black, and the epidermal is correct----ish.
I have then swapped this for an unhidden MR mix8 layer, which is a cool shader, but the same thing happens…
This is what I want it to look like, and was achived by rendering using normal MR buffer, and each layer visable at a time, and comped in Fusion. This method is slow, so this is why I want to spit all the channels together…
**So lets re-cap…Mega_TK works sort of, but isnt seeing the composite map layers, only the top one of the stack…Mix8 has the same problem, only the top one comes out.
**Second issue is the layer that Mega_TK exports looks a bit odd, and I suspect is something to do with 32bit float gamma or what not…has anyone else come accoss this…so even if I could get this to work the final layers take extra CC in fusion before I can combine them…
Apologies for the long post, hopefully this makes sense.
I know Blur Studios are using MR for Max for their productions, so Im guessing they must split up skin passes, its so useful to have that control, someone somewhere must have done this…this is why Im here…! 
edit im now finally using Max2010, coz of so called MR upgrades