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View Full Version : Miss Fast Skin - Color Mixing - Anyone know the rule?


ghostlake114
04-05-2006, 11:16 AM
Okie...assum that I could use Miss fast SSS now and at this time, my problem is color mixing for a good skin color
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First, the color of my skin base on back,mid and front color of SSS, not overall.. diffuse value keep at default
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So, the skin color is the mixing of three color, back, mid and front
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This is the result of back SSS when the weight of mid and front SSS is 0 and the back is 0.5
http://i18.photobucket.com/albums/b132/maxxoros/backSSS.jpg
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Then, I changed the weight of back and front sss -> 0,change the weight of mid sss -> 0.4
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http://i18.photobucket.com/albums/b132/maxxoros/midSSS.jpg
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The last, mid and back is 0, front SSS is 1 now
http://i18.photobucket.com/albums/b132/maxxoros/frontSSS.jpg
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This is the result when I render with 3 color
back weight: 0.5
mid weight: 0.4
front weight: 1
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http://i18.photobucket.com/albums/b132/maxxoros/back_mid_frontSSS.jpg
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Ah ha, we see that the color of final pic is some kind of color mixing from 3 color above... I try with Photoshop CS2 but CAN NOT FIND a way to mix 3 layer of color to the final color above
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Anyone know how we could blend this three color outside Maya ... So that, we could make better material for front SSS and mid SSS
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Thanks a lot for any information and help
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PS: I also read the thread of master Zap about pass of Hulk, but It is only seperate each pass like I do above, not the way to make a composite outside Maya

Stahlberg
04-07-2006, 12:59 PM
You mean you're using the default settings for colors in those 3 layers? I don't understand how you can get green then, because they're all reddish by default... ? Unless you're using a version where someone has changed the setting to greenish colors.

anyway, the back color is not mixed with the others, not in this case. Shouldn't be at least. It's only used if the surface is thin enough and you have enough light coming in from the back. So forget about that for now.
If you can really see a difference on the main body when you change the back color settings, your radii are too large. Try raising the Algorithm > Scale Conversion value.

ghostlake114
04-08-2006, 01:53 AM
Ah...I changed the color for testing purpose, It s easier to see the kind of color mixing if I chaged to green.
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THe weight of front SSS is 1 so the effect of back SSS is not much... put more attention and you 'll see that the there is a little redish in the ear
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Could you tell me the kind of color mixing used by Misss fast skin? I think this is a kind of color mixing (like overlay, screen... etc) but I can not find a way to mix them outside Maya

Stahlberg
04-08-2006, 09:35 AM
pyou 'll see that the there is a little redish in the ear
Yeah ok (seems a bit too much, so can probably raise the Scale a bit).
Still, the back sss is calculated differently from the other two and since you see it so rarely in real life, and its red color isn't changing, you might as well turn it off for this test.

The blending between the 2 front sss layers is probably straight additive, that's not the tricky part.
The sss effect is calculated with complex math, I don't know the details, I probably wouldn't even understand if I was told. I think it takes into account different refractions of different wavelengths, so the final color of exiting lightrays will be slightly shifted towards the left of the spectrum. The 2 layers are calculated exactly the same, only one is thinner and one is thicker.
But you better go straight to the source and ask ZapMaster himself about all this, I'm just repeating what I think I remember him saying about it. :)

edit:
Anyway, unless you know something I don't, I'd strongly recommend against trying to get fancy with separate color maps for the dermal and epidermal layers. (And the back layer, only if you're doing something like huge bat-wings that need dark veins in them or something like that.) It's way too much work, for no perceptible gain. There's nothing you can do that way, that you can't put in the ordinary Color map (which I usually put in Overall Color).

ghostlake114
04-10-2006, 02:15 AM
Thanks a lot, Stahlberg ... I get the point
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I follow the way that learnt from www.lemiere.com/html/tutorials/tutorials.htm about human skin, that he use a epidemal map and forget about the overall color... Okie, plug the texture to overall color is easier and get the fast effect..
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But I ll try to get more information on how to get a epidemal and demal texture... This seem a rock

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