I've been experimenting with skin shader, face textures and SSS.

1. There is no description on the usage of SSS on the Hash support web site. Specifically, I could find no reference to it in the on-line reference manual. It's kind of like finding a flying saucer, lot's of fun filled promise, but ya can't read the alien language to get it going.

2. What is the difference between setting up a skin group in a model and turning on the skin shader, vs not turning on the skin shader? As long as I have skin shader enabled in the render settings, the skin has the shader applied. Only when I turn off the shader setting in the chor does the face come out pasty.

3. Does SSS work on skin that has a 100% color decal applied? So far I can see very little difference in using SSS and not using it. I know I am not using the right setting, but ya know about that durn alien language. There is a setting that has something to do with density. Are they talking about my head?

4. I put a light directly behind a character that has SSS applied, yet I see no translucent edges on him. MOF even if I turn up the intensity to 1000% I can't even tell there is a light behind him. I thought SSS was supposed to make the skin a wee bit translucent?

5. ....

Not an expert here, but the plugin "skin shader" and SSS are two separate things not meant to be used together.

The BEST place to find out about SSS is by asking here on the forum or running a forum search (recommended) Are you sure you have turned on SSS in the renderer? Are you up to date with V 15.0G? Any version previous to that is iffy.

Video Tutorial on SSS

http://www.hash.com/forums/index.php?showt...p;hl=Scattering

Thanks for the info so far. Just want to verify about the use of the skin shader not to be used with SSS?

You mean

Plugin Shaders>ON >Diffuse Render Shader>Skin

?

It's meant to somewhat imitate the way light shades skin in the absence of a real SSS feature. It's faster than SSS. Yves added it before SSS.

If you turn on any plugin diffuse shader it overrides what you have set in the regular surface settings so it's probably undoing whatever you are setting for SSS.

In any event, it's not a part of SSS since SSS is for many things besides skin.

Is multi-pass required for SSS?

Now that you mention it, I may not have turned on the SSS option in the render dialog box since AM now crashes immediately upon start of the render process - exception #10. Turning off the SSS option generates a trouble free render. I thought V.15g got rid of that crash upon render problem? I also made sure the SSS group is at the bottom of the groups list.

Narrowed it down to my model since a new chor with a basic box with SSS applied rendered fine.

After more experimenting, I am starting to believe SSS is very unstable. I shut down AM, then my computer. Restart of computer and AM should have gotten me a clean slate. Then I started a brand new blank project and made a simple cube by extrusion. All normals were facing out. I selected the cube, grouped it and enabled SSS in the group with 100% density, and values for RGB as 1, .75, .5. Dragged this cube into a new chor, opened the render dialog, left everything at default except for turning multi pass off and turning SSS on. Pressing the start to render button caused an immediate exception #10 error. Going through that again caused the windows error reporting window to pop up asking if I want to send an error report to MS because AM has encountered a problem and needs to shut down.

Anyone have any ideas? I upgraded to V15 mainly for SSS.

Use larger extinctions.

yeah, I never got a render to finish with the default numbers. Most examples I see people post here had double digit numbers.

Could someone who had positive results with SSS post their render and the associated values please? In the SSS video, Jason shows Zaryn's alien bust. What values did that take?

My latest results are less than stellar, although this time AM did not do an Amilia Earhart. Here is the render. Settings are 100%, 5, 1, 3. Time was about 8 minutes for a singles pass. I'd hate to think how long my complex model would take to render? Taking off the SSS decreases render time to 3 seconds. Below is the SSS render vs non SSS.

Eric I have been playing quite a bit with sss and to date I have had AM only crash twice. I found it quite stable. I run rgb on extinction 2 1.25 1 and relative density 150% This ranges on the extinction pretty close to this numbers depending on the ability to show light. This changes with each character and what look I am going for. I may go higher but it creates a waxier look and you can create a look like BOB in monsters vs aliens with higher numbers. Here is a shot with the settings I stated of the Cindy i am working on with sss only.

Steve

Thank you, thank you, thank you. I was starting to feel more than a little lost here. How long did it take to render your model?

Well, I started a render with those settings and so far so good, no immediate crash. Do I need multi pass with SSS?

could someone please expain this skin shader

It can take a long time with extinction low and percentage high. This shot took 13 minutes to render but the slow down was with the particles, I rendered the same shot without the hair and it was about 4:58 a frame. It has been mostly a trial and error.

Steve

Skin shader: Select the group you want to apply the skin shader to - for now leave the settings at default. Once you are ready to render, select shader/skin in the render option and render away. The skin shader gives your model a richer tone that tries to emulate human skin. I like it.

Easy enough to test but I'm glad you've asked anyway.
This topic is sure to help a lot of folks with SSS!

The answer of course: No, you don't need Multipass with SSS.

Shelton:

your hair really looks nice - ahem, I mean your model's hair. Do you use color maps for length, direction, etc, or is it just hard grooming work? Also, do you groom in the modeling window or in a pose or in an action? Obviously I am trying my hand at a character and have zero experience with it. Mechanical modeling is so much simpler

Eric

Also, multipass is not required. It creates a richer tone in my opinion, however. The picture I uploaded is with no multipass. (3:52 is what it took to render without the hair). Also keep in mind to group your entire skin object. If you copy and attached the model with group skin already created with sss make sure you delete the second group such as skin2 and group the entire skin as one object. What I have noticed even though I had grouped the skin under one object the object created when I copy attached was still in the heirachy. It rendered with lines in it. I deleted both the groups. Created a new group and applied sss to it after copy and attached. Also decals are applied after the sss created. I have the lips with a decal now and will have eye shadow and the rest with a transperency once the I get the hair done and rigged. It works really well.

Steve

Ok, the second render came out fine, but I still don't see the translucency I am hoping for. Below is a three pass render with the first sphere having no shader and no SSS, although the Planet glow applied to the second sphere also took on the first sphere - strange. The third sphere has SSS with 200% density, 5, 1.25, and 4. Which way do I have to skew the values to get a translucent look?

While I'm asking a lot of questions and getting some good responses, can anyone tell me why the first sphere took the Planet glow of the second sphere? I double checked and the first sphere's group properties definitely have no shaders, nor do they intersect with the second groups properties.

When doing your SSS tests here's a recommendation:

Make sure the object you are using has variation to its thickness.
While you can get some nice effects with solid objects with equal thickness you'll get see more of the effect by having thick and thin areas in your model.

IMO, The solid block (edit: or the sphere) with no variation in thickness isn't going to be the best test.

Edit: Added a quickly lathed example but more extreme variation would be better.

I do the hair in modeling window. Only because I am not going to use dynamics in the short. With everything else going on I thought it might be too much. I will revisit this later.

To groom the character's hair I created a skull cap, keep 4 point patches if possible and with reduced mesh (hair can do funny things with 3 and 5 point patches). Then I grouped the cap into different objects such as back, sides, top, and bangs. I created a the hair material and then applied to each new hair object. I hide and un hide those hair objects and groom the hair seperately. I use and move the control points rather the hair brush tool to groom. I then hide all but the hair cap and the groom the hair together by using the density of each object to help from moving some control points. I use both the control points to lengthen or shorten and to adjust and finally use the hair brush tool to finalize the look. It takes an evening to do the hair for her. The other characters I finished in an hour to two.

Steve

Eric

My last post dissapeared. Trying using the extinctions with higher numbers that will give the effect you are looking for.

Steve

Pulled out my first female head bust and applied SSS. It's rendering now with slightly higher values. Still nothing in the double digits. I guess I am using such low values because that's what I remember from the SSS video tutorial that Jason posted. I'll post my Kate bust as soon as it's rendered.

The pic below rendered in one minute and 11 seconds. Settings: 150, 15, 8, 12. There are no other groups in this model, no decals, and no shadows enabled during render. Wonder what the green cast is on the lips and eye lids?

Your green is the lowest setting and it will be the one that shows the most when patches are close to gether such as eyelids. Go ahead and apply a color to the surface and rerender

Steve

nice start on the model

I guess my optimism was misplaced - I just slightly changed the SSS values and now the render is taking forever. I stopped the render - it wasn't even going past 0% - deleted the only group in the model. I then made a new group and tried to render again. It's still going and still not even registering 1% done - still at 0% after 10 minutes. Wait, it just jumped to 58% at 11 minutes. That must have been the time it took to calculate the SSS. Finished at 14:59 - 12,1,8 This was rendered before I read your last post Steve.

Ok, cautiously singing Happy Days! This render is with a skin color applied, small spec values and SSS at 150, 10, 12, 10.5 Only took 34 seconds to render.

I used these settings on my original model, the one that crashed each time I used SSS and now it rendered fine. Ok, I'm officially stoked! Thank you Steve and Rodney for helping me out here.

Take the percentage up to 200 and that will help get rid of the lines

Steve

So SSS and the skin shader plugin do work in conjunction together?

Attached are a small collection of successful SSS settings with examples.
Click to view attachment

Gotta say I'm really happy with SSS, I kind of stumbled across it while I was looking at different shaders in preparation for texturing and am pleased with the effects I'm getting.

This model has zero textures or shaders atm; the skin is all SSS. Full 1080HD resolution, took 2:16 to render. 200% SSS sampling (SSSS?).