Somethings to Consider when starting to learn CG

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  • SzarkSzark Posts: 10,539
    edited December 1969

    Are you using the Global Illumination setting for UE2 by any chance?

  • adaceyadacey Posts: 177
    edited December 1969

    No, indirect lighting with soft shadows. I had originally loaded in UE in GI mode, so no sphere was loaded, but switched modes after the crippling render times.

  • SzarkSzark Posts: 10,539
    edited December 1969

    Ok IDL and GI both need settings to be super sampling....so the shading rate of UE2 should start at 0.20 - 0.10 or even as low as 0.01. The Advanced Render Settings Shading rate drop down to 0.10 or lower.

  • adaceyadacey Posts: 177
    edited December 1969

    Okay, this is what I'm getting with a shading rate of 0.01 for UE. The banding is only in the arms, although there's some in her legs too, so I'm going to double check if I have anything odd going on with my skin materials on those mat zones. Also see that I still have some hair issues but it's pretty minor at this point.

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  • scorpioscorpio Posts: 6,207
    edited December 1969

    Are you using uber surface on the skin the banding can sumtimes be got rid of by increasing the subsurface scale.

  • SzarkSzark Posts: 10,539
    edited December 1969

    scorpio64dragon thx I keep forgeting that one.

  • SzarkSzark Posts: 10,539
    edited December 1969

    I should have asked...do you know what this Scale value represents?

    If not it is the thinkness of the surface that the SSS has to penatrate. When using pwSurface a value of 1 works well. I see DT uses 1.70 for Uber Surface in his Interjection products. I have also noticed some skin textures sets coming in loaded at a value of 4. IMHO I think this is way to thick for human skin.

  • adaceyadacey Posts: 177
    edited December 1969

    Uber Surface 2 has a SSS shading rate setting and I think that's the culprit. I stumbled across it while checking the SSS scale (was defaulted at 1) and in a bit of confusion between samples and shading rate, I cranked it up to 128 from its default of 32 and got this horrible result. I'd discarded the changes there and had left it as I was discouraged from the lack of progress.

    But, I just had the flash of realization that low is what you want for shading rate so I'm re-rendering now with all of the surfaces dialed down to 1 for SSS shading rate, will post the result when that's done. Given how much worse it got from cranking it up I'm hoping this is the correct slider and that dropping it from 32 to 1 will be a good improvement.

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  • SzarkSzark Posts: 10,539
    edited December 1969

    I have never needed to change the SSS Shading Rate before and I have used some fairly advanced shaders and lighting and never come across this issue personally before.

    Are both light sources set to 0.10 shadow Bias?

    As for the eyes this is Genesis isn't it? If it is I haven't done much works with Genesis but I do know it does have a Cornea surfaces like the Gen4 figure have and that would have been easy to advise.

    Since I can't even run DS4/4.5 I can't help further.

  • adaceyadacey Posts: 177
    edited December 1969

    Subsurface shading rate did the trick, dropped that down to 1 and this is what I got.

    I double checked my settings and both the area light and UE were set to 0.10 for shadow bias.

    For the eyes, yes as far as I can tell the Genesis surfaces are the same as Gen4 surfaces. I was applying the reflections on the cornea material. I was using 0% opacity, 100% reflection, raytraced reflections with fresnel active. I think that's the main pertinent settings. Might have to try one with fresnel turned off. I'd experimented quite a bit with just zoomed in on the eye and it seemed to improve things but zoomed out it looks bad so maybe that's the culprit.

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  • SzarkSzark Posts: 10,539
    edited December 1969

    Well I learned something myself today, thanks adacey.

    Well the last time I used Genesis it didn't have a Cornea surfaces at all.

    If that has changed then I will dig out the settings of the Cornea at least.

  • adaceyadacey Posts: 177
    edited December 1969

    Thanks Szark, that's a big part of why I've been trying to keep this thread alive, there's a lot of useful info in it already and I figure if I'm working through a problem then odds are good somebody else is hitting the same issue.

  • SzarkSzark Posts: 10,539
    edited December 1969

    and I really appreciate that adacey thank you.

  • SzarkSzark Posts: 10,539
    edited February 2013

    This is the problem with not having access to DS4.5 I had no idea they brought back the Cornea surface for Genesis...I just had it confirmed.

    For me this is good news but how to set it up better.

    The first thing to do is turn OFF the Specular "Multiply Through Opacity" setting, What does this do?

    With Multiply Through Opacity turned OFF lets the render engine know that there is a transparent object/surface in the scene the will need specular highlights and Reflections. This is also true for Glass. If you using low opacity and high reflections and specular highlights for any surface/s and not using opacity maps turning this OFF will help achieve those results. If you are using a Opacity map then this needs to be ON otherwise you will get reflections and/or highlights on parts that should be invisible. :)

    Opacity between 40 and 50% works quite well if you are using a reflection map.

    If using a reflection map then place the reflection map (usually a black and white map) in the Diffuse Colour and Opacity channels still turning OFF Multiply Through Opacity in the Specular channel

    If you are not using a reflection map and want crisper looking eyes try 0% opacity and as long as your light set up is good enough and you turn OFF Multiply Through Opacity you should get good reflections. I am doing an animal image at the moment and even at 0% Opacity I am getting nice reflections on the cornea.

    Reflection colour 255,255,255 white
    Reflection Strength (for real reflections we do need something in the scene to reflect) 100% or lower to taste. If using a reflection map then 0% will be best. :)

    Ok hope that helps with the Cornea surface.

    Oh yeah if you want help with the other parts like with SSS for the whites etc just yell. I am still here to help but with having to wait to get to use the laptop makes it hard to get online much these days.

    Post edited by Szark on
  • StormlyghtStormlyght Posts: 636
    edited December 1969

    adacey said:
    Thanks Szark, that's a big part of why I've been trying to keep this thread alive, there's a lot of useful info in it already and I figure if I'm working through a problem then odds are good somebody else is hitting the same issue.

    Thank you @adacey and @Szark for keeping this thread active! I've learned a great deal from it. I lurk for the most part but I wanted to chime in and let you know that I'm appreciative.

  • SzarkSzark Posts: 10,539
    edited December 1969

    stormlyght thank you. That is the best part for me, more than a pat on the back, is if you learn something from it. But it is sure nice to hear it from time to time. :)

  • adaceyadacey Posts: 177
    edited December 1969

    OKay, I'm now fairly confident in saying that it's fresnel that's causing my cornea issues. It seems like it doesn't work well with transparency, at least in Ubersurface 2, might have to try the default DAZ shader to test if it behaves differently.

    If you check Omnifreaker's site you'll see that the fresnel effect shows the sphere as black in a lot of spots, this appears to still happen when combined with 0% opacity where, in my mind, it should be completely transparent in those spots, not darkened.

    I tried without the fresnel effect and just got too strong of a reflection so I tried with some reduced reflection strength and fresnel on, I then got some transparency in the cornea but things were still too dark. Now trying a lower reflection with fresnel off.

  • SzarkSzark Posts: 10,539
    edited February 2013

    Why have Fresnel on in the first place. It isn't crystal glass. :)

    Seriously yes we could use Fresnel but unless you are going for serious realism then I wouldn't bother. I haven't played much with Fresnel to be honest but I do know it can be fiddly to get the right settings. This is one of those aspects that needs understanding of how Fresnel works in the real world and then finding the right settings in the CG world.

    Seriously I wouldn't complicate things at this stage keep it simple. I have no idea why some people even use Fresnel on the skin.

    Post edited by Szark on
  • adaceyadacey Posts: 177
    edited December 1969

    It was mostly from mucking about with settings when I was zoomed right in on the eye, turing it on helped tone down some of the room reflections while keeping a nice catch light. But, while zoomed out it just made everything too dark (downside of tweaking materials with everything but the eye turned invisible.

    100% reflectivity looked a little too intense with fresnel turned off but fixed the brightness issue at least so I'm thinking just keeping it off but dialing back the reflectivity is the way to go.

  • SzarkSzark Posts: 10,539
    edited December 1969

    I agree, lower the reflection and leave fresnel out of the equation.

  • SzarkSzark Posts: 10,539
    edited December 1969

    Now that I borrowed a machine that can run DS4.51.56 I can finally get around to a few things.

    Firstly HSS (Human Skin Shader), Uber Surface and Uber Surface 2 but before I wade in a sharing with what I think I know I want to ask you (blanket you) if you think I am ready to part with my hard earned knowledge. This is a WIP but I wanted to see if I am worthy of the task I put before me. If you think the image below is good, skin and eyes wise then I will progress and get everything down on virtual paper. But I warn you this is going to take time so please be patient.


    I have used Uber Surface on nearly every surface and use SSS on all the skin and eye whites and teeth. Also added fresnel and refraction on the Corneas etc..

    .

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  • scorpioscorpio Posts: 6,207
    edited March 2013

    Pretty good.

    The only thing I don't like completly is the Tshirt, it seems to have a sheen to it that that sort of cotton doesn't usually have.

    Can't seem to get the pic to enlarge - ok got it to work, internets a bit glitchy at the moment.

    Post edited by scorpio on
  • SzarkSzark Posts: 10,539
    edited December 1969

    LOL WIP Yeah haven't got around to dealing with other mats yet just the figure. I will deal with that later.

  • scorpioscorpio Posts: 6,207
    edited December 1969

    Sorry.
    The skin does look very good

  • SzarkSzark Posts: 10,539
    edited March 2013

    oh don't be sorry please. You spurred me on to set up Uber Surface on the shirt and getting some nice results. :) I even went and imported the gun into Blender and applied a subD and smoothing mod to it and applied Uber Surface to that once back in Daz Studio. Oh man it really come up well if I don't mind saying myself.

    Just tinkering with the lightings now. I have to confuess that image had its Levels adjusted in PS, only a bit. ;) I am trying to get close inside Daz Studio, but with this rig any really advanced lighting will have to wait. I am just using Area lights, Uber spots and UE2 for ambient fill only. I am just tweaking to get a better contrast and balance.

    Post edited by Szark on
  • scorpioscorpio Posts: 6,207
    edited December 1969

    I wondered about what lighting you were using, I don't know if I've ever used UE2 with Area lights, I will have to give it a try.

  • SzarkSzark Posts: 10,539
    edited December 1969

    yeah but UE2 is set to Ambient Only meaning no Ambient Occlusion set to a mid to light blue at 5% Intensity and no map in the colour channel. It just filsl out the shadows a little more. Plus with using all Uber lighting (area dn spots)I can control the strength of the shadows and the colour.

  • SzarkSzark Posts: 10,539
    edited December 1969

    Pretty good.

    The only thing I don't like completly is the Tshirt, it seems to have a sheen to it that that sort of cotton doesn't usually have.

    Can't seem to get the pic to enlarge - ok got it to work, internets a bit glitchy at the moment.

    Plain render out of Daz Studio no postwork. How does the shirt look now?
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  • adaceyadacey Posts: 177
    edited December 1969

    Looking good so far! Now you knew I was just going to have to ask about the cornea settings right?

  • SzarkSzark Posts: 10,539
    edited March 2013

    LOL Yeah I did think that might be coming

    This is for UberSurface2

    Diffuse Strength 0%

    Opacity 0%

    Refraction ON
    IOR 1.38

    Spec
    Colur White
    Strength 82%
    Glossiness 84%
    Spec Sharpness 67%

    Spec 2 Colur White
    Strength 60%
    Spec 2 Roughness 89%
    Spec 2 Sharpness 97%


    Reflection
    Raytraced
    Colour White
    Strength 85%
    Blur 1%


    Multiply Refection Through Opacity OFF

    Fresnal
    Strength 50%
    Falloff 1.00
    Sharpness 1%

    I also used the Eye morphs that I have for Genesis (not sure which pack they come with or come as standard) and used the Cornea Bulge Morph at 40%. Saves using a bump map. :)

    Post edited by Szark on
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