View Full Version : SSS_fast_skin + PSD using mix8layers/js_multilayers??

01-25-06, 11:24 AM
Can someone please help me fill in the blanks?

I'm reading that you can use mix8layers to make layers, masks, etc.
on top of a SSS_fast_skin shader which will inherit the effects
of the SSS_fast_skin shader.


My goal is to create realistic skin, but add details to the skin in
photoshop that can mix with the effects of the SSS_skin_shader.

(Note that I'm unable to select a UV set when creating a PSD node.
Sometimeswhen I am able to select a UV set, the attributes are gone.)

So when I create a PSD layered node/file, the uv set is unlisted.

I saw a forum post that talked about layering UV sets:

It looks like the guy who started this thread is having the same
questions about layering that I am. The thread mentions
using UV sets. So I tried using the relationship editor
to connect shaders with different UV sets.

Quote from another forum:
The way the UV sets work is like lets say you have a brick wall
like you said.. or a skin texture.. since this is going to tile and
repeat.. you wouldn't need to go far and have a grand UV map
for it.... just a unified projection would be enough. But Lets say
you want to put a poster/Grafitti on your wall... and this time you
have to have the whole wall projected onto a planar mapping.
You simply create a new UVset and and give it a distinctive name.
In the UV connection editor, you could later on assighn the
poster texture onto the second set.. and the brick texture onto
the UV original Set. (I usually use this for displacement maps..
since unified and spread out UV coords give me a better result I
prepare that one seperately)

Does this mean you can overlap UV sets like layers?

Anyway, when I tried openning the relationship editor,
I wasn't able to figure out how to connect the UV's
to the shaders. I went to Relationship editor > UV linking >
texture-centric. I'm able to see the shaders and UV
sets, but no matter what I try, I can't seem to connect them.
Isn't it as simple as highlighting the UV set from one
column and highlighting the shader in the shader column?

So are there two methods?

1. Overlapping UV sets (i.e. applying the SSS to one UV set,
and applying the PSD layer node to a copy of the first UV set).

2. Using mix8layers (i.e. placing PSD node on layer one, and placing
SSS on layer two).

The person on the other thread that I mention says he has figured it out:

The standard Layered Shader in Maya doesn't support Mental Ray
rendering that good, so I found the mix8layer Shader on
www.Highend3D.com which works pretty much like layers in
Photoshop (you can select a whole load of mixing techniques).
I connected my SSS_fast_skin Shader to color.layer0 (base color)
and my blinn to color.layer1. Important though is to connect the
lmap (lightmap) file for the SSS material to the Shading Group of
mix8layer (instead of the old SSS SG). And finally, connect a file
node (the alpha map) to o.factor in layer1 (also, I went with
normal.mix in blending mode).

Can someone tell me what is meant by "connected SSS_fast_skin to
color.layer() andmy blinn to color.layer1" ?

And "And finally, connect a file node (the alpha map) to o.factor in
layer1 (also, I went with normal.mix in blending mode" ?

Even when I open up the UV relationship editor, I don't see anything listed as
"color.layer()" or "color.layer1".

If using UV sets as layers is not the answer, and using mix8layers
or js_multilayers to mix layers is the better solution, is there anyone
gracious enough to write a visual tutorial to help us clearly understand the steps?

It's possible indeed to separate the sss contribution. Internally the misss
does screen-compose the sss over a diffuse contribution. So all you need
to do is switch the diffuse weight (not the diffuse color!) to 0, or switch
ON Subsurface Contribution Only in the shader itself respectively.
This way you might screen-layer the misss over/under any other
contribution (scar etc.), using any of the available mix-shaders like
Pixero's, Francesca's mix8layer, etc.pp. If you want to go the marlboro
man's way: You dont need a single custom shader. Take the misss, the
other (diffuse?) contribution, invert them both using Reverse node,
multiply the inverted result together using a Multiply/Divide node, and
invert the multiplied result again using another Reverse node. Et voil?.

Could someone perhaps put together a quick visual tutorial to explain this?
Sorry, but it's hard for this novice to understand.