Step-by-Step: Using the new PBR Skin on Genesis 8



  • cgidesigncgidesign Posts: 396
    edited February 2022

    PBR in general:

    It means "physically based rendering". The idea is to simulate real world light and surface behaviour in 3D.

    More about it here (it is free):

    "PBR Skin" and "Uber Skin":

    A renderer (e.g. Iray in DS) needs instructions how to do this real world simulation (e.g. how bright is the light, how rough is the skin, how translucent is the cloth).

    Those instructions are put together in "shaders". In DS those shader values can be set in the "Surfaces".

    PBR Skin and Uber Skin are both exmaples of shaders. Both are pbr shaders (meaning both follow the rules of pbr rendering in general) but DAZ decided to call one "PBR Skin" which leads to some confusion.

    HD addon:

    As far as I know there are no "HD addon skin" products but "HD addon" ones. They cover two parts of real world simulation.

    • how detailed the shape of an object is
    • how detailed the textures used in the shaders are

    Shape of object:

    Basically a HD addon makes the shape of the object more detailed (e.g. more folds, wrinkles in the face, maybe defined rib bones on the body etc.). But what an HD addon delivers depends on the PA who created it. For more about the concept search the web for "subdivision modeling" or "sub-d modeling".

    Textures used in the shaders:

    Shaders use "textures" (also called "maps") to control some of the shader values. E.g. there is a texture to control the base color of the skin. But there are other textures which often are called "control textures". Those do not drive the color but the surface appearence. Quite often people talk about "skin details" and mean the small pores and wrinkles human skin has. Those details can be controlled by so called "bump-", "height-" or "normal-maps". Those maps tell the renderer how to simulate the fine skin details.

    If the PA decides to do so, a HD addon can contain those special control maps and they might be made in very detailed quality. The base figures you buy might not include those maps or in a less detailed quality.

    Skin resources:

    There are a few products in the store which are not a HD addon (they do not offer anyting about the shape detail of a figure) but they include very detailed textures. Those ones can be used to replace the textures that came with the figure you bought and might even include more detailed maps than the what a HD addon includes.

    One way to find those products is to search for "skin resource" in the DAZ store - or ask in the forum to get suggestions.



    Post edited by cgidesign on
  • MelissaGTMelissaGT Posts: 2,521

    cgidesign said:

    What is causing those strange shadows around the nose and chin? It looks somehow wrong to me (a bit like ambient occlusion is added into the lighting mix). But beside of that the skin look great.

    That odd shadow is the one of the reasons I don't care for the new Iray PBR Skin Shader and still prefer the Uber Shader. 

  • lemipslemips Posts: 23

    I have been trying to figure out those dark edge shadows as well. I discovered just now that turning on Specular Occlusion seems to get rid of them, but I'm having a hard time determining what else that setting is doing to the specular.
    Does anyone know precisely what Specular Occlusion does?


    Here are a couple test renders of V9 with a few tweaks to the shader and the same HDRI (thats for sharing that btw, excellent light!) with SO off then on. You can see it fixes the odd shadows but also affects the rest of the shader's specular a LOT.
    Another note, turning Specular Occlusion Grazing up causes the edge shadows to return...


    (Btw forgive me if this was already covered, only skimmed this thread.)



    1435 x 1030 - 2M
    1435 x 1030 - 2M
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