Approaching Realism in DAZ Studio and Gamma Correction Demystified

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Comments

  • dakkuuandakkuuan Posts: 295
    edited December 1969

    Here is my attempt at using the principles talked about on this thread. It's using the V6 HD Anna skin. It's rendered in Daz Studio 4.8 Beta 3Delight. Thoughts?

    Cristy_Anna_Skin_Complete_Gama.png
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  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited April 2015

    dakkuuan said:
    Here is my attempt at using the principles talked about on this thread. It's using the V6 HD Anna skin. It's rendered in Daz Studio 4.8 Beta 3Delight. Thoughts?
    I know I'm going to be handed my back-side for saying it, tho, my thoughts.

    Looks allot better then my attempts.. Some of the minor things that take "Post Processing" to fix. The skin has a hint of lack of color to it, and some shadows are not dark enough (Like the inside of the elbow on her left arm).
    (EDIT)
    Oh, the "velvet" probably could be turned down just a pinch. Also it almost looks like some one turned off "cast shadows" on the hair and shirt, or a light is not set to cast shadows.

    Post edited by ZarconDeeGrissom on
  • jpb06tjpb06t Posts: 272
    edited December 1969

    I downloaded the image and gave a look at the histogram. The darkest color luminosity was about 35 and the whitest about 248 so I rescaled the range and got this picture. I think that the thing works pretty well.

    Cristy_Anna_Skin_Complete_Gama.png
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  • evilded777evilded777 Posts: 2,283
    edited December 1969

    I like it quite a bit.

    What shader did you use on the skin?

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited April 2015

    latego said:
    I downloaded the image and gave a look at the histogram. The darkest color luminosity was about 35 and the whitest about 248 so I rescaled the range and got this picture. I think that the thing works pretty well.
    Much much, much better.

    There you have it. The only other thing I notice, would require looking at the shirt bump/displacement, and possibly bumping it up a smidgen (just a Little, not removing zeros), to get some of that cloth texture back from all the soft-lights. On the red part, if that is a separate zone.

    Post edited by ZarconDeeGrissom on
  • Oso3DOso3D Posts: 14,019
    edited December 1969

    Is there an easy way to tell if a map was set at gc 1 or 2.2?

    Trying to absorb the thread's info...

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited April 2015

    Is there an easy way to tell if a map was set at gc 1 or 2.2?

    Trying to absorb the thread's info...

    In Studio, as for the setting that tells 'TDLmake' what gamma to apply to a map, well, it's in the surface settings.

    Left-click a map, and select, "Image editor", then look at the Setting.
    This will let you see what the setting is at. '0' (zero) tells TDLmake to just guess if it is not in the image file header.

    Most files in a computer, after a camera, or made by MS Paint, are at gamma 1.0, so the Gamma 2.2 output of the display, shows the image properly. (That's 0 for black, 127.5 for mid gray, and 255 max white, in an 8bit scale, AKA 24bit image file)

    As for the setting in an image file header??? IrfanView v3.98 dose not show it, that I can find.
    (there are newer versions of Irfanview, that I don't use, as they have strange image viewing resize issues)

    WhatIsGammaAt_IrfanView_v3d98_001.png
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    WhatIsTheGamma3_001.png
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    WhatIsTheGamma2_001.png
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    WhatIsTheGamma1_001.png
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    Post edited by ZarconDeeGrissom on
  • plopsplops Posts: 29
    edited December 1969

    As an engineer, does this mean that a surface is a surface and a light is a light? therefore, using raytraycing (surely this is how light behaves?) if the programme works and the lights are the right colour to suit the situation and the shadows are set to your preference, (Over simplification I know) then the result will look right?
    I have just spent a long time reading this thread, trying to learn about "Macro skin" ie: is it an effect that can be applied to any Gs character or is it a "character preset". I believe the latter.
    I have learned quite a bit, mainly that when it comes to computers, Geeks rule, but need guidance from simpletons (like me) to include a few basic presets that will allow an acceptable result in several situations, IE: press this, this or this. As well as the Massive amount of variations that are available for "Artists" as discussed in this thread.
    As artists, I find it strange that you have to work so hard to get the results you want from a programme that is so difficult to use, and doesn't listen to much that its users (Customers) say.
    You, (The artists) shouldn't have to be involved in the technecalities of the software, that should be down to the geeks and DAZ.

  • prixatprixat Posts: 1,172
    edited December 1969

    Most files in a computer, after a camera, or made by MS Paint, are at gamma 1.0, so the Gamma 2.2 output of the display, shows the image properly.

    That's not quite correct. (What I mean is... that's completely wrong :-P )

    Gamma 2.2 is slapped on to every image almost immediately, we never get the chance to see the 'Linear' version.
    For example in a digital camera where the sensor is linear, a gamma curve is applied immediately so that even the RAW file is 'corrected'.

  • dakkuuandakkuuan Posts: 295
    edited April 2015

    Anna uses AoA subsurface by default. I'll have to tinker with some of the settings. The great thing about getting this right is the of the 3 characters I render most often, two use the same skin, except one doesn't wear make up. So after I perfect Anna, Lilith is next. Changing the diffuse texture on the skin does wonders. I wasn't very fond of Anna until I toned down the diffuse. I didn't spend much time on the clothes and your right, they aren't producing shadows at least by the look of the pic. I'll have to play around a bit more. I'll turn down the velvet too and see what happens.

    EDIT: Latego that looks great. As for shadows, most of the lights have shadows on a few didn't so I turned them on and I'm going to try re-renderering. As for the hair and top, they did have shadows on.

    Post edited by dakkuuan on
  • evilded777evilded777 Posts: 2,283
    edited December 1969

    plops said:
    As an engineer, does this mean that a surface is a surface and a light is a light? therefore, using raytraycing (surely this is how light behaves?) if the programme works and the lights are the right colour to suit the situation and the shadows are set to your preference, (Over simplification I know) then the result will look right?
    I have just spent a long time reading this thread, trying to learn about "Macro skin" ie: is it an effect that can be applied to any Gs character or is it a "character preset". I believe the latter.
    I have learned quite a bit, mainly that when it comes to computers, Geeks rule, but need guidance from simpletons (like me) to include a few basic presets that will allow an acceptable result in several situations, IE: press this, this or this. As well as the Massive amount of variations that are available for "Artists" as discussed in this thread.
    As artists, I find it strange that you have to work so hard to get the results you want from a programme that is so difficult to use, and doesn't listen to much that its users (Customers) say.
    You, (The artists) shouldn't have to be involved in the technecalities of the software, that should be down to the geeks and DAZ.

    Sorry, but I disagree with you.

    There is no "Click Here to Make Art" button.

    What you are talking about is paint by numbers; sometimes you are gonna get something great, mostly you are not.

    A tiny bit of knowledge goes a long way and can allow one to make a huge leap. A large part of the problem is the huge variety of vendors who interpret things on their own or based on the work of others and perpetuate hacks and outright mistakes. Not that I don't appreciate the work of those vendors... they ought to know I do, they have enough of my money. Compound this variety with a lack of rational, equal standards, and you get the soup we have today.

    Studio is not difficult to use, its one of the easiest software packages I have ever learned. Its far easier than the other leader in this realm, in my opinion.

  • dakkuuandakkuuan Posts: 295
    edited December 1969

    Another attempt, I used a more white values for the diffuse. I might have gone a bit too far, I don't know. I turned down the velvet and made the bump adjustments to the shirt. I'm mostly interested in perfecting the mat for the character, so any other possible suggestions would be awesome.

    Cristy_Anna_Skin_Complete_Gama_2.png
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  • Mustakettu85Mustakettu85 Posts: 2,693
    edited December 1969

    plops said:

    I have learned quite a bit, mainly that when it comes to computers, Geeks rule, but need guidance from simpletons (like me) to include a few basic presets that will allow an acceptable result in several situations, IE: press this, this or this. As well as the Massive amount of variations that are available for "Artists" as discussed in this thread.
    As artists, I find it strange that you have to work so hard to get the results you want from a programme that is so difficult to use, and doesn't listen to much that its users (Customers) say.
    You, (The artists) shouldn't have to be involved in the technecalities of the software, that should be down to the geeks and DAZ.

    I'm sorry I could not understand the first paragraph of your post at all. Do you mean that using GC will ensure the renderer gets the correct inputs? Then yes, it is what it does.

    Now, apart from what Evilded777 said, I would like to emphasise one simple fact:

    3D artists _should_ be involved in the technicalities. It is in the job description. Think of VFX/CG studios. Even purely lighting artists - who do not have to write shaders but will only use models and shaders made up the pipeline - even they are required to understand the basics of how everything works. And not just the software, but the real world.

    Traditional artists will study optics and physical technique of applying paint or some other coloured medium onto paper/canvas/garage walls. It takes years.

    3D artists will study optics and mathematical technique of applying and setting up shaders (light/surface/volume...). It takes years, as well.

    Just like getting good in any other field.

    What makes Studio "difficult to use" is not Studio itself. Again, DS is a well laid-out application. It's the lack of a unifying methodological approach.

    If there is anything extra DAZ the company should have done, it was to have enforced a proper nomenclature, for starters. Not even every PA here at the flagship store will know the difference between a shader proper and a shader preset (just take a look at the marketplace for proof).

  • Mustakettu85Mustakettu85 Posts: 2,693
    edited April 2015

    Is there an easy way to tell if a map was set at gc 1 or 2.2?


    Assuming your maps are 8 bit per colour (low dynamic range, like JPEG):

    If it is a diffuse map and on your screen it looks the way you expect that object to look in the real world - then it's 2.2.

    If it's a bump, displacement, transparency or normal map - then it is linear (because there are no real-world colours in it).

    Assuming your maps are 16 or 32 bit per colour (high dynamic range, like EXR, HDR or a certain type of TIFF):

    They are always linear.


    An image viewer/editor will let you see the bit depth.

    ...someone mentioned PNG possibly having its "own gamma". For all intents and purposes, don't let it bother you. It used to be an issue for web designers back in the prehistoric world, so nobody really does it anymore.


    mjc1016 said:
    Computers are great at crunching numbers, but to get the expected results, they must have the correct input. Linear workflow IS that correct input. Everything else is pretty much like putting in random data and expecting a sensible result...

    Oh right, the less harsh description would be incorrect workflow.


    -----------

    Another attempt, I used a more white values for the diffuse. I might have gone a bit too far, I don't know. I turned down the velvet and made the bump adjustments to the shirt. I'm mostly interested in perfecting the mat for the character, so any other possible suggestions would be awesome.

    She looks excellent in this lighting. One thing I'd check is if there is any velvet on the lip material. It doesn't really belong there.

    You could try an opposite style of lighting to make sure the materials will work across most situations: something less diffuse, with a more pronounced key light with stronger shadows, coming from the side.

    Post edited by Mustakettu85 on
  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited April 2015

    prixat said:
    Most files in a computer, after a camera, or made by MS Paint, are at gamma 1.0, so the Gamma 2.2 output of the display, shows the image properly.

    That's not quite correct. (What I mean is... that's completely wrong :-P )

    Gamma 2.2 is slapped on to every image almost immediately, we never get the chance to see the 'Linear' version.
    For example in a digital camera where the sensor is linear, a gamma curve is applied immediately so that even the RAW file is 'corrected'.And thus the confusion.

    So if a camera dose NOT apply a Gamma of 0.45 to a file it makes from the light it's taking a Picture of.
    So If the monitor (Graphics card, or display driver) is NOT applying a Gamma of 2.2 to the image being displayed.
    Then a file in the computer is What then? What is Mid Gray in MS Paint, if it is not 127.5 (0.5 in some systems) ???
    (EDIT)
    Here is a simple graph, What is the curve???
    because, at the end of the day, when I'm making maps in MS Paint. That is all I care about, where is mid-gray?

    8x8_InToOut_003.png
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    FromCamera_toFile_ToDisplay_001.png
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    Post edited by ZarconDeeGrissom on
  • jpb06tjpb06t Posts: 272
    edited December 1969

    ...someone mentioned PNG possibly having its "own gamma". For all intents and purposes, don't let it bother you. It used to be an issue for web designers back in the prehistoric world, so nobody really does it anymore.

    The gAMA chunk is part of the PNG specification so, unless you have other information, it is at least sensible to check whether it is used and if so what value it contains.

  • jlorelljlorell Posts: 3
    edited December 1969

    She looks excellent in this lighting. One thing I’d check is if there is any velvet on the lip material. It doesn’t really belong there.

    You could try an opposite style of lighting to make sure the materials will work across most situations: something less diffuse, with a more pronounced key light with stronger shadows, coming from the side.

    Thanks Kettu. I will really try her out in a different lighting. Thanks for the suggestion with the lips too.

  • prixatprixat Posts: 1,172
    edited December 1969

    So If the monitor (Graphics card, or display driver) is NOT applying a Gamma of 2.2 to the image being displayed.
    Then a file in the computer is What then? What is Mid Gray in MS Paint, if it is not 127.5 (0.5 in some systems) ???

    Oooh, time for another car based analogy?!

    If your speedometer is properly calibrated then when it indicates 70mph there's a good chance you are pretty close to 70mph.

    Similarly if your monitor is properly calibrated there's a good chance you're seeing the image on screen pretty close to what is should be.

    In the same way that your speedo cannot change your actual speed, the monitor has no control over the actual of the image.
    (If you still want to think of the monitor gamma as correcting something, its correcting for the silicon lottery of its components and the choices of the designing engineers.)

    As for the actual value of mid-grey, we don't have to worry about it directly.
    Display a mid-grey on screen and the monitor knows 127 needs to be around 196 to look right, but to the program its still a value of 127 being sent to the graphics subsystem.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited April 2015

    prixat said:
    So If the monitor (Graphics card, or display driver) is NOT applying a Gamma of 2.2 to the image being displayed.
    Then a file in the computer is What then? What is Mid Gray in MS Paint, if it is not 127.5 (0.5 in some systems) ???

    Oooh, time for another car based analogy?!

    If your speedometer is properly calibrated then when it indicates 70mph there's a good chance you are pretty close to 70mph.

    Similarly if your monitor is properly calibrated there's a good chance you're seeing the image on screen pretty close to what is should be.

    In the same way that your speedo cannot change your actual speed, the monitor has no control over the actual of the image.
    (If you still want to think of the monitor gamma as correcting something, its correcting for the silicon lottery of its components and the choices of the designing engineers.)

    As for the actual value of mid-grey, we don't have to worry about it directly.
    Display a mid-grey on screen and the monitor knows 127 needs to be around 196 to look right, but to the program its still a value of 127 being sent to the graphics subsystem. So I don't have to fuss with making odd curves in MS Paint, :lol:

    Joking aside, So the Proper Gamma curve for maps made in MS Paint, should(?) look like this?
    This is where it gets confusing for me. That looks rather linear to me. It's a straight line, not a curve. :blank:
    (EDIT)
    Not trying to put you on the spot, it's just that every time I'm questioned about gamma, I tend to want to call sRGB files 'Linear', because of the attached non-curve. I'm tempted to call that Gamma 1.0, because there is no curve to it.

    8x8_InToOut_MsPaint_BMP_Gamma_Question_001.png
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    Post edited by ZarconDeeGrissom on
  • dakkuuandakkuuan Posts: 295
    edited December 1969

    Here is one using the Sci-Fi Warrior lights. I killed the velvet on the lips for this as well.

    Cristy_Anna_Skin_Test_Shadows.png
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  • dakkuuandakkuuan Posts: 295
    edited December 1969

    Oh on a side note, apparently V6's Belle's Diffuse Map's gamma is set to 1 by default. So if anyone wondered why she gets a cloudy eye look when rendered with GC on without any other alterations, that's why.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited December 1969

    dakkuuan said:
    Oh on a side note, apparently V6's Belle's Diffuse Map's gamma is set to 1 by default. So if anyone wondered why she gets a cloudy eye look when rendered with GC on without any other alterations, that's why.
    that is curious. not that it is set to one rather then any other number. That it is not treated by TDLmake in a proper way with GC on, and the image file gamma clearly set???
  • dakkuuandakkuuan Posts: 295
    edited December 1969

    Sorry I made a slight error in my last post. V6 belle's eyes diffuse map are set to one. everything else is either 1 where it should be and 0 for most other things. I find it rather odd myself.

  • ZarconDeeGrissomZarconDeeGrissom Posts: 5,361
    edited December 1969

    dakkuuan said:
    Sorry I made a slight error in my last post. V6 belle's eyes diffuse map are set to one. everything else is either 1 where it should be and 0 for most other things. I find it rather odd myself.
    An equally good question. If the setting in the surface tab is set to '0' (zero), and at that setting TDLmake uses the image file header for that info... Is the gamma setting even in the file?

    Going way back in time, it was never a concern. All files displayed on a computer, were either of substantial lack of color depth (sixteen colors), or they were all meant to be displayed by a CRT that did that Gamma 2.2 thing for the computer. So I can comprehend there being a time where image file formats did not bother to include such 'Gamma' properties.

    I've done a little digging thus far (been buisy with other stuff), and what I've managed to find is not all that informative about the behavior of TDLmake with gamma settings. In fact it raises more questions, lol.

    TDLmakeCommands_Gamma_001.png
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  • PUREDIGITAL101PUREDIGITAL101 Posts: 26
    edited December 1969

    this is what I came up with using your macro skin, (many thanks for the hard work) been using luxrender for ages
    but when I saw you have put this together I had to try it now if i can only get good
    looking hair using 3d delight

    lilly2.jpg
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  • PUREDIGITAL101PUREDIGITAL101 Posts: 26
    edited December 1969

    an another example of macro skin using 3D delight and point and shoot lighting

    http://www.daz3d.com/photo-studio-point-and-shoot-2

    studio_girl.jpg
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  • plopsplops Posts: 29
    edited December 1969

    plops said:
    As an engineer, does this mean that a surface is a surface and a light is a light? therefore, using raytraycing (surely this is how light behaves?) if the programme works and the lights are the right colour to suit the situation and the shadows are set to your preference, (Over simplification I know) then the result will look right?
    I have just spent a long time reading this thread, trying to learn about "Macro skin" ie: is it an effect that can be applied to any Gs character or is it a "character preset". I believe the latter.
    I have learned quite a bit, mainly that when it comes to computers, Geeks rule, but need guidance from simpletons (like me) to include a few basic presets that will allow an acceptable result in several situations, IE: press this, this or this. As well as the Massive amount of variations that are available for "Artists" as discussed in this thread.
    As artists, I find it strange that you have to work so hard to get the results you want from a programme that is so difficult to use, and doesn't listen to much that its users (Customers) say.
    You, (The artists) shouldn't have to be involved in the technecalities of the software, that should be down to the geeks and DAZ.

    Sorry, but I disagree with you.

    There is no "Click Here to Make Art" button.

    What you are talking about is paint by numbers; sometimes you are gonna get something great, mostly you are not.

    A tiny bit of knowledge goes a long way and can allow one to make a huge leap. A large part of the problem is the huge variety of vendors who interpret things on their own or based on the work of others and perpetuate hacks and outright mistakes. Not that I don't appreciate the work of those vendors... they ought to know I do, they have enough of my money. Compound this variety with a lack of rational, equal standards, and you get the soup we have today.

    Studio is not difficult to use, its one of the easiest software packages I have ever learned. Its far easier than the other leader in this realm, in my opinion.

    Hi!
    I'm replying mainly to show good manners, I was very drunk when I wrote that and i'm a bit drunk now, but thanks for noticing.
    I'm not trying to do painting by numbers, as a total amateur working with no restrictions or deadlines, I spend hours trying (touching and playing) with any and all of the knobs and switches provided, that is my enjoyment. I don't want a scientific approach to the creation of something so natural as a girl walking along a street for example, in the same way as I don,t read music, but I play rock/blues guitar that makes me smile.
    I am trying to learn more about Studio because I believe that a working knowledge of the tools you are using leads to better results, this I call common sense. However, I believe that in the real world, certain materials have specific properties, like the refraction index of specific transparent substances, so when using ray tracing, (if it is real ray traycing) then some basic guidance or presets could be indicated or included within the interface. I am pretty shure Jackson Pollock didn't worry about the material his brushes bristles were made of while he was throwing paint at a canvas.
    There is more than one approach to art in any medium, don't deny youreself, have fun, I do.

    ps: with a memory like mine, and the fact that some artists put their products under differing names in their respective directories, Studio is not that easy for all

    I should reply to Kettu also but it is stupidly late here and the merlot is still calling.

    No harm intended, non taken.

  • Mustakettu85Mustakettu85 Posts: 2,693
    edited December 1969

    latego said:

    The gAMA chunk is part of the PNG specification so, unless you have other information, it is at least sensible to check whether it is used and if so what value it contains.

    I'm so sorry to be saying this, but what you're doing by this, is confusing people (particularly newcomers) and not much more.

    First of all, not that many DS/Poser products out there actually _come_ with PNG maps.

    Next, no sensible person would be messing with gAMA in 2015. Not even a web designer.

    Some things are obsolete.

  • Mustakettu85Mustakettu85 Posts: 2,693
    edited December 1969

    dakkuuan said:
    Here is one using the Sci-Fi Warrior lights. I killed the velvet on the lips for this as well.

    This is lovely. The hair could use some adjusting, but I believe it's just a "placeholder" right now, correct?

    -----------

    If the setting in the surface tab is set to '0' (zero), and at that setting TDLmake uses the image file header for that info... Is the gamma setting even in the file?

    Tdlmake uses whatever DS tells it to use. And generally, DS tends to guess at 2.2 when the slider is at zero.

  • evilded777evilded777 Posts: 2,283
    edited December 1969

    Hypothetically, if one wanted to do their own gamma correction on images before passing them to the render engine, how would you do that?

    And correct me if I am wrong here, if I was to correct my textures by hand, I would then leave GC off in render settings and leave the gamma value at 1.

    Hit me.

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