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free data -> human skin example

AndyGrimmAndyGrimm Posts: 910
edited December 1969 in The Commons

This project may be of interest for some of you...

http://gl.ict.usc.edu/Research/DigitalEmily2/

I did not have the time yet to download and play with the datas - but it is on my to do list... maybe we can implement one or two things

for DAZ iray shaders...

So i am starting this thread in the hope to get some together and post and improve skin settings.....

Maybe we set a ligth standard scene and tone mapping/camera setting )using a reference chart?)....so that we are able to compare our serttings under the same conditions? Suggestions ?


Well i am new here - still learning DAZ (but did my first renderman image using a DOS prompt :-).... I will learn DAZ while doing my tests and taking part here in the forum. Struggling with the mdl shader mixer right now :-)

happy rendering

Andy

Comments

  • algovincianalgovincian Posts: 2,581
    edited December 1969

    AndyGrimm said:
    This project may be of interest for some of you...

    http://gl.ict.usc.edu/Research/DigitalEmily2/

    I did not have the time yet to download and play with the datas - but it is on my to do list... maybe we can implement one or two things

    for DAZ iray shaders...

    So i am starting this thread in the hope to get some together and post and improve skin settings.....

    Maybe we set a ligth standard scene and tone mapping/camera setting )using a reference chart?)....so that we are able to compare our serttings under the same conditions? Suggestions ?


    Well i am new here - still learning DAZ (but did my first renderman image using a DOS prompt :-).... I will learn DAZ while doing my tests and taking part here in the forum. Struggling with the mdl shader mixer right now :-)

    happy rendering

    Andy

    Thanks for posting the link, Andy! Downloading now . . .

    - Greg

  • MattymanxMattymanx Posts: 6,881
    edited December 1969

    AndyGrimm said:
    Maybe we set a ligth standard scene and tone mapping/camera setting )using a reference chart?)....so that we are able to compare our serttings under the same conditions? Suggestions ?


    I did a night scene once and struggled with how to make the skin look good in a darker environment. I came to this conclusion, if you can make the skin look good under daylight settings then it should look good under any lighting condition. So I set the scene up as a day time shot first and then replaced all the lights with a night set.

  • jpb06tjpb06t Posts: 272
    edited December 1969

    Does anybody know how to convert the Alembic mesh to OBJ or something like that?

  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    I did a night scene once and struggled with how to make the skin look good in a darker environment. I came to this conclusion, if you can make the skin look good under daylight settings then it should look good under any lighting condition. So I set the scene up as a day time shot first and then replaced all the lights with a night set.
    ..


    Yes - same here in my case. I am not sure yet that daz iray or nvidia iray in general really reproduce real world physik in low ligth situations... i am a ambitious photographer myself, using nikon fullframe and 1.8 lenses.... i can do a great skintone just with a candle and some low ambient ligth... while the same settings in daz iray.. change skin tones very non natural....

    I also noted extrem differences using just the sun sky.. what looks great 8pm (standard daz).... is way to bright and over exposured 12pm even with changed standard camera settings (just the skintone, eyes working - which proves me that we are far away from a "real" skin simulation)...


    So to get a real comparision of different skin shaders and how they react in harsh, warm and photometric light... we need minimum 3 "standard" ligth settings and matching camera settings...

  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    Does anybody know how to convert the Alembic mesh to OBJ or something like that?

    Copy paste (wiki)

    Tools which support Alembic[edit]
    Tools with native support[edit]
    Application As of version Vendor
    Maya 2012 Autodesk[6]
    3ds Max Yes, as of 2015 Extension 1 Autodesk[7]
    KATANA 1.1 The Foundry[8]
    Houdini 11.1 Side Effects Software[9]
    RenderMan ? Pixar[10]
    Arnold ? Solid Angle[11]
    MODO 601 The Foundry[12]
    NUKE 7.0 The Foundry[13]
    Cinema 4D R14 Maxon[14]
    V-Ray 2012 Chaos Group[15]
    Guerilla Render 0.15.2 Mercenaries Engineering[16]
    RealFlow 2013 Next Limit[17]
    Maxwell Render 3 Next Limit
    Clarisse iFX 2012 Isotropix
    LightWave 3D 11.6 NewTek[18]
    Keyshot Pro 4 Luxion
    Octane Render 1.5 Otoy

  • AndyGrimmAndyGrimm Posts: 910
    edited June 2015

    what i clearly missed while doing my tests with daz skins: Control over diffuse reflection... Specularity reflection is one thing (that's why most renders looks ether flat or like glossy plastik)... but the change to liveless skin in other ligth situation happens mostly because of wrong or missing diffuse reflection...

    Also a WET skin is nearly not possible with the standard shaders... same reason here.

    But i am sure i just overlooked something :-)


    Also the terminilogy is not clear to me? Glossines? Reflection ? that's one and the same or not? Glossines depends on specular reflection or not?

    Well - if someone can guide me to a clear explanation of what the terms used in daz iray really mean - i could not find a guide or a technical specification myself.

    Post edited by AndyGrimm on
  • WendyLuvsCatzWendyLuvsCatz Posts: 37,944
    edited December 1969

    Gueriila Render is the only free thing in that list, I have downloaded not tried it, whether it will export is more the question.
    Octane only imports alembic and only exports renders and Octane scenes.

  • AndyGrimmAndyGrimm Posts: 910
    edited June 2015

    I am sure somebody here has one of the big apps installed - we need the mesh and the texture to render a reference skin in daz - so it would be very nice when the first person which is able to extract the datas could share them to us here. The files are open source and free for study-- everything legal...

    Such a reference texture skin is a big advantage to develop daz model skins for iray and test different shader channels and values. All tests which i saw yet did use a not optimized texture.... a to much saturated diffuse texture while missing the real datas in specular, diffuse reflection and so on. Using this texture set - we have a real reference model to test iray skin shaders against each other.

    Post edited by AndyGrimm on
  • WendyLuvsCatzWendyLuvsCatz Posts: 37,944
    edited December 1969

    I read a red disclaimer saying otherwise
    the best option would be to contact them and request an obj or other DAZ compatible format be added
    DS is a new player in the iray arena so they probably only think of the big name apps.

  • WendyLuvsCatzWendyLuvsCatz Posts: 37,944
    edited June 2015

    Meanwhile DAZ could use an alembic importer, this could be useful for so many things, something the Devs can think about as rigging from other apps does not import, I have resorted to morphed animation myself from other apps but tedious hand doing it.

    Post edited by WendyLuvsCatz on
  • WendyLuvsCatzWendyLuvsCatz Posts: 37,944
    edited December 1969

    Zbrush opens the Maya file

    emily.JPG
    1924 x 1080 - 181K
  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    I read a red disclaimer saying otherwise
    the best option would be to contact them and request an obj or other DAZ compatible format be added
    DS is a new player in the iray arena so they probably only think of the big name apps.
    ...

    rights of use: the red disclaimer is about the"IMAGE" of emily (she is also a real person :-)

    http://www.wikihuman.org/#/digital-emily-2-data-now-available

    NOTE: This data is NOT for resale and for NON-Commercial use only.....

    Also a update with OBJ is promised:


    12 June
    Copy paste from their blog...

    Digital Human League members have been working hard with the Digital Emily 2 data for the last several weeks. In doing so several adjustments were made based on our finding. We will be documenting those changes and posting and update to the data. Besides the updated data, we will also be posting more data based on requests such as OBJ formats, and lighting that matches the reference.

    The Mission:

    The Digital Human League was formed with both an artistic and scientific motivation in mind. Together, as a group, the DHL will embark on a large scale project called Wikihuman. The goal of the project is to study, understand, challenge, and most importantly share our knowledge of Digital Humans..

    http://www.wikihuman.org/index.php/about-us/

  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    heck? how did you open alembic in zbrush? you must use a magic trick.. i get a error.

  • jpb06tjpb06t Posts: 272
    edited December 1969

    I love certain "free" things... this muscle car is free but, if you pretend to drive it, you have to buy a 200,000$ engine...

    Apparently the OBJ version is coming.

  • Richard HaseltineRichard Haseltine Posts: 97,731
    edited December 1969

    AndyGrimm said:
    heck? how did you open alembic in zbrush? you must use a magic trick.. i get a error.

    She opened a Maya file, I think, not the Alembic file.

  • AndyGrimmAndyGrimm Posts: 910
    edited June 2015

    I love certain “free” things… this muscle car is free but, if you pretend to drive it, you have to buy a 200,000$ engine…

    Apparently the OBJ version is coming.

    Maya has a 30 day free trial... i will also have to install it to figure out their shader set up.


    Zbrush opens the Maya file

    She opened a Maya file, I think, not the Alembic file. Yes.. thank you @Wendy & Richard... late nigth and i completly overlooked the Maya file :-)... Works like a charm - mesh and textures are in DAZ. Now the difficult part begins :-)
    Post edited by AndyGrimm on
  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    i think it is ok when i share the obj mesh - if someone like to join just send me a PM.

    The goal is testing own skin shaders using the same reference model and textures and light and compear with others.

    emily-daz.jpg
    1366 x 768 - 505K
  • ncampncamp Posts: 345
    edited December 1969

    I opened the Alembic file in Modo no problem. Waiting on downloading the maps to see if they can be used.

    EmilyHead.png
    1920 x 1032 - 523K
  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    Here is a very informative document which i once bookmarked.... it explains understandable:

    A Physically-based Human Skin Reflection Model

    http://www.wseas.us/e-library/conferences/2009/prague/ICAI/ICAI01.pdf...


    If you have links to similar ressources and datas dont hesitate to post them right here.

    skin_layers.jpg
    772 x 603 - 196K
  • ncampncamp Posts: 345
    edited December 1969

    OK, so the Alembic file opens with no UV mapping. If there is a way to import the UV mapping in Modo, I don't know how to do it.

    ncamp

  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    Hello ncamp :-)


    Great to see others joining in the round.

    Over the last weeks i followed every thread about skin in this forum - and despite that i saw some great renders - the provided values just did not make any sense (with some exceptions such as the infos from MEC4d)

    so i welcome everybody which can feed my hunger for learning more about :-)

  • jpb06tjpb06t Posts: 272
    edited December 1969

    AndyGrimm said:
    to figure out their shader set up.

    No need to install anything get the OSL file for the shader.

  • AndyGrimmAndyGrimm Posts: 910
    edited June 2015

    No need to install anything get the OSL file for the shader.

    I should have said "shader AND lighting" setup.... they use Maya and will publish the whole scene in their next update. That's how i understood it... So if i want to compare their setup and results with mine .. i dont see a other way then to take a look in Maya with their datas. Or do you have another idea? :-)

    Post edited by AndyGrimm on
  • AndyGrimmAndyGrimm Posts: 910
    edited June 2015

    the first test render - displacment to less - micro dissplacment (bump) is ok.... translucency color (red) is to dark, But everything else looks very promising - specularity map is amazing real.

    This render is just to get a feeling for the maps.... used my old skin shader settings on the PBR Spec/Gloss for this one....

    A shader similar to the orginal OSL will take me some days. my entry 1gb nvidia is to weak for fast tweaking.

    Seeing the skin rendered with daz, i think it is definitly a reference and a great study object.

    emily1.png
    1080 x 1080 - 760K
    Post edited by AndyGrimm on
  • jag11jag11 Posts: 885
    edited December 1969

    The folks at The Wikihuman Project have made available a Wavefront OBJ version HERE.

  • AndyGrimmAndyGrimm Posts: 910
    edited December 1969

    Thank you - did you or someone else a render with her skin in DAZ allready...? i should have time next week to continue.

  • jag11jag11 Posts: 885
    edited December 1969

    AndyGrimm said:
    Thank you - did you or someone else a render with her skin in DAZ allready...? i should have time next week to continue.

    A quick Iray render, still long way to go. I didn't follow the instructions to build the suggested shader.

    Emily.png
    720 x 960 - 759K
  • Arnold CArnold C Posts: 740
    edited April 2016

     

    AndyGrimm said:


    If you have links to similar ressources and datas dont hesitate to post them right here.

     

    Nice Project! :)

    That's some of the stuff I found during my web-research about the human skin topic:

    Chapter 14 of NVIDIA's "GPU Gems 3" and some interesting further references:

    https://developer.nvidia.com/gpugems/GPUGems3/gpugems3_ch14.html

    http://developer.download.nvidia.com/presentations/2007/gdc/Advanced_Skin.pdf

    http://etd.uwaterloo.ca/etd/akrishna2005.pdf

    http://seer.ufrgs.br/rita/article/viewFile/rita_v11_n1_p33-62/3553

    http://www.npsg.uwaterloo.ca/resources/docs/eg04.pdf

    http://graphics.ucsd.edu/papers/egsr2006skin/egsr2006skin.pdf

    http://www.cs.columbia.edu/techreports/cucs-024-05.pdf

    http://www.researchgate.net/publication/269514946_Optical_properties_of_the_human_skin__Optike_osobine_ljudske_koe (can be downloaded from the link "Download full-text" on the top right of the document window).

    The goal is testing own skin shaders using the same reference model and textures and light and compear with others.

     

    One thing that's wrong at first glance on your current shader model is that your "Glossy Color" is at 0.54 grey.
    Section 14.3 "Specular Surface Reflectance" of GPU Gems 3 describes, of what color specular reflection of human skin (and other dielectric materials) is and why:
    "Specular Reflectance from Skin Is White".
    Also, the "Glossy Specular" is way out of range, it's range is from 0.0289420 to 0.0387250 for human skin, and related to the Refraction Index.

    Post edited by Arnold C on
  • davidtriunedavidtriune Posts: 452

    I rendered her and shared her in this thread https://www.daz3d.com/forums/discussion/313401/iray-photorealism/p13

     

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