Realistic Skin Shader C&C


#1

Okay I’ve been working on tweaking this shader for a while and I would like some critiques on the Shader and eyes only. I did not model this head, Lyr modeled it. He provided it to the Maya Shader Discussion Site for our use in developing a shader.

Software used:
Maya 6.0.1
mental ray Misss_Fast_Skin_Maya shader (Found in this thread)
mental ray 3.3

Requested Critique:
I would like honest critiques of the shaders only. Please do not C&C the modeling. I am not concerned with it at this point.

  • Does this shader look like real human skin? If not, why.
  • Would it fool the average person if the model was given proper hair?
  • Do the eyes have “life” to them, do they look like real eyes. If not, why.

Latest update:

************ 1st post images - left here for reference ***********

Wireframe:

Renderings:


#2

I’m not really qualified to critique (the last time I gave my opinion that a drawing looked somewhat awkward someone dug up one of my sketches :frowning: ) , but I will seeing that I observe the human race every day. :wink:

First of all, the eyes look a little strange to me. I think the white part of the eye is too white.

Also, it appears you have left out the cornea (see the side picture. I think you actually need to eye surfaces…one kind of glassy (this would be the reflection bit, and then the iris part. Technically, the iris almost lays flat inside the eye while the cornea provides the arch around it. I’ve found this easier to see with an animal like a cat since they tend to have large corneas.

These might help:

Eye Color/Shading/Skin
Little Bit of Cornea/Skin
Cornea

Her skin looks a bit dry to me. The ears also need a bit of translucence.

I hope that helped. It’s like I said, I can’t model, draw, or texture very well so take what I say with a grain of salt. Cheers.


#3


#4

The overall oclor is too plane. I think it needs specular and diffuse maps and more specific bump map (does it has those maps?). Anyway, the color texture look good to me.


#5

You need better sss - looks too plasticky right now. You have too much white in the eyes - i don’t know the proper names of the parts of the eye, but there is that red bit on each side, and the inside has a lumpier red bit :stuck_out_tongue: talk about scientific lingo. You also need some small veins in there. I’m with virum about you needing a cornea. The nostrils also should have more shadow in them. Since you gave her lipstick, I’m assuming thats a “painted face.” If she’s wearing makeup her cheeks would have more pink in them. Looks like you were aiming for an unmakeupped face though… but that would look odd, and her eyebrows and eyelashes are done nice, and the lipstick… so, look at closeups of diff types of makeup, and aim for shaders that look like makeup. You definitely need better translucency, especially in the ears.

(Look up how prosthetic/glass eyes to have a better understanding of how the eye’s structure influences how it looks [pun unavoidable] and how people perceive that it’s real.)

Good start! I’d like to see updates.


#6

Updates:


#7

Right side its still too plane. The perspective view its better now with the specular. About the lips, its true that you can see a tonal color difference, like she has the lips painted with the color of the skin, i think its better to paint it more red (or other color), or try to eliminate the tonal diference that she has now.
Anyway, i think she looks good now. I like.
Sorry about my english.


#8

You did that with the fast_misss_skin_maya?Wish I could get such a result, I like it! Keep up the work.


#9

Personally I think it’s a little too plastic looking. I don’t think it looks too plain though, as some people are suggesting - skin can be plain in real life.

What you really need to incorporate is that peach fuzz look that skin has from the tiny hairs on it. It’s similar to a velvet look and you can fake it in Maya with ramp shaders (using the camera view as the input).

Colour-wise the skin looks quite orange to me… but it could just be my monitor :slight_smile:


#10

Nice indeed.

The ears on the model are unfortunatly too simplistic (geometrically) to make the “see through” bit of the sss look realistic. But that ain’t your fault, just making the observation.

Are you using the edge enhancement of the specular component(s)? That gives you a wee bit of the “peach fuzz” feel.

Another thing you can try: Throw in an environment (even a solid color can work, such as the gray bg you have now) and turn the reflection_weight to 0.1 and reflection_edge_weight to 1.0, and if you want fast test renderings set reflect_environment_only to “on” (but for finals this should probably be off)

/Z


#11

@Leigh:
Hi Leigh. :slight_smile: I agree with ya about it being too orange. It’s something I’ve been struggling with lately. I think one of my SSS settings is wrong, I’m planning on working on fixing that this morning.

Is it too plastic looking overall or just in spots? I’m stil tweaking my spec map, I think it falls apart on the side view.

Thanks for the tip on the peach fuzz, I had almost forgot that. I’ll work on it after I tweak the color and spec.

@Zap:
Yea, the ears are kinda messed up, but in my final model the ears will be hidden behind hair so I’m not too worried about them for now. Later on, if I have another model where the ears are going to be seen I’ll definately tweak the shader to look spot on.

yep, I’m using the edge enhancement, but I’m still tweaking it. Gonna try to get that peach fuzz look after I get the color and spec balanced.

I have a IBL added to the scene, is that what you mean by “environment”?


#12

You can change the colour easily in post though, so it’s not a major concern. Nothing like a quick Adjustment Layer in Photoshop to fix things up :wink:

The spec thing appears to be an overall problem. What I tend to do is avoid specularity altogether with organic surfaces, and stick to low level reflection mapping instead. It yields far more realistic results when used correctly. I only use specularity on plastic surfaces.

As for your SSS settings - I think they also may be causing the head to look… hollow. I don’t quite know how else to describe it. It looks like a hollow ball for some reason. I honestly don’t know how to fix that though.

It’s looking good though - I think all it needs are some minor tweaks here and there so don’t panic too much!


#13

Tocpe, can you post your texture maps for this model? I want to start contributing some tests for the shader discussion site, but haven’t the time to paint any maps.


#14

It looks better… but still not 100%. If you are trying to fool people who don’t know it’s CG, they will know its CG.

check out this link, it’s fromKodak’s website, a sample photo from their 14 megapixel camera. You can see lots of detail, peach-fuzz, pores, etc on the face, color, sss, etc…

click here

This might help. (And yea, it seems too orange to me, too.)


#15

Thanks for the feedback guys. I’m still working on it, I think I may have managed to get a good bit if not all of the orange out of it. I’ll post a new update when I have a few of these other issues worked out. :slight_smile:


#16

i think you should losen the edge of the lips a bit. The lip’s outline is looking unaturally crisp-sharp


#17

Update:


#18

I was finally able to get the reflections to work properly in the Mi_SSS shader.

C&C’s?


#19

Holy crap!

If it weren’t for that mangled ear geometry, I would say that’s damn near a photo!

So, what was the problem w. reflections? How did you fix it?

It looks fantastic!

/Z


#20

Thanks Zap! Couldn’t have done it without your cool shader and the help from my fellow Mac Maya users translating the shader over.

I found that turning all the specularity off for the shader was one part. The other part was tweaking the reflectance to the following values along with a very dark reflectance map was what did it:

Spec Overall Weight = 1
Spec Edge factor = 2

Reflect Weight = Relectance map goes in here
Reflect Edge Weight = 0.25
Refect Enviro Only = unchecked
Reflect Shininess = 2.75