SSS shaders

1235»

Comments

  • SzarkSzark Posts: 8,762
    edited December 1969

    mark128 said:
    megagearx said:
    Thanks again for the help!
    I guess it doesn't work too well with V5...I see white streaks showing up on the model.

    The V5 Bree skin material is setup to use the UberSurface shader. Applying UberSurface to the Bree skin should not do anything.

    that's it I am off the bed,,,good call mark.....


    kicks myself serverly.

  • mark128mark128 Posts: 880
    edited December 1969

    Szark said:
    mark128 said:
    megagearx said:
    Thanks again for the help!
    I guess it doesn't work too well with V5...I see white streaks showing up on the model.

    The V5 Bree skin material is setup to use the UberSurface shader. Applying UberSurface to the Bree skin should not do anything.

    that's it I am off the bed,,,good call mark.....


    kicks myself serverly.

    Gedd is right though that it might still change some settings.

    I recently discovered that applying UberSurface to a skin using the standard shader changed the UVs from V5 to V4. That caused some banding that took me a long time to notice because I was concentrating on the face.

  • mark128mark128 Posts: 880
    edited December 1969

    I decided to try to apply UberSurface to Tori for V5 (http://www.daz3d.com/tori-for-v5 ). She has pale skin and freckles. The skin is setup using the DAZ Default Shader. The problem I have with this skin is it has a very high level of ambient. Ambient color is 198,165,154 and strength is 20%. This is a glow in dark kind of setting. It makes it hard to cast shadows on her face. You also need to turn down your lights to prevent blowing out the highlights on her skin. This makes it difficult to render a scene with Tori and other characters in it.

    For lighting in the images I am only using 4 UberArea light planes. The key light is camera right and above. The fill is camera left and at camera level. There are two back lights camera left and right that are high. I am not using UberEnviroment2. Why am I doing the lighting this way? The main reason is with this lighting setup on my computer a render at 1200x900 takes about 12 min. I have tried to use UberEnviroment2 and after an hour it was still rendering the eyebrows. So I can try a lot more settings with this light setup.

    The first picture below illustrates the problem with the brightness of the Tori skin. The two images were rendered with exactly the same lighting. On the left I applied the V5 Bree skin to the Tori character and on the right is the Tori skin with all default settings.

    You can of course deal with this by reducing the lighting. In the second image on the left is Tori with default skin rendered with lights reduced to about 80% of the previous renders.

    The first thing I did was to try to fix the settings with the default shader more to my taste. I took all the ambient out, and adjusted the specular a little. In the second image on the right is Tori after these adjustments with the default shader and lights back to 100%. I have taken the pink out of her face by removing the ambient. I could put some pink back into her face with diffusion color, but I planned to do that with SSS, so this was my starting point.

    tori02.jpg
    2000 x 1250 - 322K
    tori01.jpg
    2000 x 1250 - 333K
  • mark128mark128 Posts: 880
    edited December 1969

    Here is where I have gotten so far using UberSurface shader on Tori. I have only applied it to the skin surfaces. The nails and eyes are still being done with the default shader. Settings at the moment are listed blow.

    One thing I notice is the freckles do not stand out as much as in the original render before my adjustments. Taking the pink ambient out even with the default shader seems to make the freckles less obvious.

    I'm not completely happy with the specular yet and I still need to try to setup the Velvet, but this is where I have gotten so far.

    Diffuse Color: 250, 255, 255 – take just a bit of red out
    Diffuse Strength: 95%
    Diffuse Roughness: 1.00

    Specular Color: 222,255,247 – brought over from default material
    Specular strength: 100% with a dark strength texture. Strongest on lips.
    Glossiness: 35%
    Specular Sharpness: 0.0%

    Specular 2 Color: 222,255,247 – brought over from default material
    Specular 2 Strength: 8%
    Specular 2 Roughness: 30%
    Specular 2 Sharpness: 0%

    Ambient: Off
    Reflection: Off
    Fresnel: Off
    Velvet: Off – haven't had time to try

    Subsurface Color: 128,0,0
    Subsurface Strength: 20%
    Subsurface Refraction: 1.3
    Subsurface Scale: 0.10
    Subsurface Shading Rate: 32

    Translucency: Off

    tori_uss_big.jpg
    1600 x 2000 - 2M
  • SzarkSzark Posts: 8,762
    edited December 1969

    Sertorial said:
    Gedd said:
    Yes actually I had already come to that same conclusion (that it might actually be a shadow.) Someone else posted a picture with the same effect that made me think of it, don't remember exactly where I saw it now though. Try turning off cast shadows on the eyelashes.

    the eyelashes don't appear as an item in the scene tab so I can't turn off cast shadows. There's no shadows option in the shader tab either.

    ?

    As I thought Uber Surface 2 has a Cast Shadows toggle switch in the surfaces pane but US1 doesn't.

  • SzarkSzark Posts: 8,762
    edited December 1969

    mark dropping the diffuse down to 80% - 90% will help with blowing out the textures, consider this a rule of thumb when applying US.

    Velvet isn't really needed for skin but used right is can simulate back lighting. But if you intend to try it use a similar colour to the rendered skin but more saturated.

    True IOR of skin is between 1.39 and 1.41.

    Using Area lighting will make getting good specular harder so I pop in a spot set to specular light only at about 30% intensity with 100% soft shadows and deep shadow mapped shadows. Saves on render time using DSM's.

    Given the nature or area lights and how the light ray are projected (see my Area light tutorial) you MAY only need one back area light.

    Overall though not bad. :)

  • megagearxmegagearx Posts: 24
    edited December 1969

    Gedd said:
    Well you are correct in that it uses the UberSurface shader and therefore there is no reason to apply it, simply adjust any settings one wants. However, sometimes adding shaders on top of an object that already has that shader will override settings that are currently applied, blowing out or resetting those settings. I thought I remembered this actually happening in the case of Bree but I could be wrong. I would have to test it and comb through the settings to be sure.

    Thanks for this post! This was what was possibly happening to me.

  • SzarkSzark Posts: 8,762
    edited December 1969

    OK folks my two tests have proved to me that either my machine is really borked or US2 is, either way SSS is not working as it should on those two images and in my many tests it works one minute and not the next. Yes I am getting error messgae when it doesn't work and no messgae when it does. But as soon as I change one channel's setting I get the error and SSS isn't working. So I am abandoning it until I get a new PC. When that will be is anyones guess.

  • mark128mark128 Posts: 880
    edited December 1969

    Szark said:
    OK folks my two tests have proved to me that either my machine is really borked or US2 is, either way SSS is not working as it should on those two images and in my many tests it works one minute and not the next. Yes I am getting error messgae when it doesn't work and no messgae when it does. But as soon as I change one channel's setting I get the error and SSS isn't working. So I am abandoning it until I get a new PC. When that will be is anyones guess.

    What error message are you getting?

  • SzarkSzark Posts: 8,762
    edited December 1969

    3Delight message #46 (Severity 2): R2086: incomplete (or invalid) parameters set for subsurface scattering (in shader 'omnifreaker/surface/omUberSurface2' on object '')

    In DS3A US2 work as it should, I just tested with not one warning message.

  • SzarkSzark Posts: 8,762
    edited December 1969

    I should add I have the latest US2 1.3 for DS4 and uninstalled it and reinstalled it in a new location, but no change. I even deleted lights and used other lights, same issue. Built a new scene from scratch and still this with SSS on and off issue is occuring. Very weird. :)

  • mark128mark128 Posts: 880
    edited December 1969

    Szark said:
    I should add I have the latest US2 1.3 for DS4 and uninstalled it and reinstalled it in a new location, but no change. I even deleted lights and used other lights, same issue. Built a new scene from scratch and still this with SSS on and off issue is occuring. Very weird. :)

    Perhaps you can explain how you tell if SSS is working from the image. I can clearly tell that SSS is injecting color in the skin, but are there other things you can look at to "tell if it is working?"

    I have tried things like varying the scale and I can't see much difference, but maybe I have to light the scene correctly and know what I am looking for.

  • SzarkSzark Posts: 8,762
    edited December 1969

    becasue when it works the image is so much different with the exact same setting as my last render. Shown below is a render when I get no warnings you can clearly see the SSS working and yes I have tried all sorts of setting variations. Besides it shouldn't happen when I just change a diffuse colour. When it does work it takes longer to render as expected and I get no warnings.

    nt9a1.jpg
    702 x 777 - 39K
  • mark128mark128 Posts: 880
    edited December 1969

    As I've posted I've been experiementing with the Tori skin in UberSurface (not UberSurface2 yet). I have been trying to decide If I can see any effects from changing the subsurface scatter scale parameter. The image below shows a finger on Tori which is side illuminated from below and slightly behind by a spot light. I set up the SS section like this:

    Diffusion strength: 80%
    Subsurface color: Diffusion texture with color 128,0,0
    Subsurface strength: 100%
    Subsurface refraction: 1.4
    Subsurface shading rate: 1

    The subsurface scale was varied between 0.1 and 4. I was using the SSS strength at 100% to try to maximize the effect so I could see it better.

    You can clearly see that the skin tone is paler when SSS is turned off. The SSS is adding a lot of pink to the skin. To my eye it looks like the SSS effects are stronger when the scale is smaller.

    Other than the skin tone, the other effects off SSS here seem much more subtle.

    Should I be able to see more effect with this kind of lighting or is this pretty much what is expected?

    scale_compare2.jpg
    884 x 300 - 19K
    scale_compare.jpg
    1339 x 917 - 74K
Sign In or Register to comment.
Rocket Fuel