Dielectric Shader WIP for download



  • Hello folks

    been working on this for a bit and here is what I have so far. You need a ShareCG account to download it. It is free to use.

    http://www.sharecg.com/v/85765/browse/7/Material-and-Shader/Poser-11-Superfly-Dielectric-Shader

    It can handle most non-metal things and with a little fiddling can do sub-surface skin textures (which I will upload when I'm happy with those and so far they look better than EZSkin3)
    I've set up this shader to be fairly easy to use and you should not have to dig any deeper than the main section.



  • could not upload the image0_1470860309163_Dielectric explanation.jpg



  • @ghostship

    Thanks :-)


  • Poser Ambassadors

    What's the advantage over the built-in PhysicalSurface?


  • Poser Ambassadors

    Also just a small spelling comment: The word is diffuse, not defuse. Defuse means to prevent a bomb from blowing up, literally to remove the fuse.



  • @bagginsbill said in Dielectric Shader WIP for download:

    What's the advantage over the built-in PhysicalSurface?

    Don't know. The one thing I do know about the Poser Physical surface is that transparency doesn't work right in it. If you take a clothing item and make part of it transparent (like cutoff jeans) the model (skin underneath) is darkened from the clothing even though it is completely transparent. This isn't right and I have know idea what else isn't right about the PysicalSN. I'm also skeptical that the original Poser root node works correctly in PBR.

    I've also had a load of issues with EZSkin3 (others have not and that is ok ) So I'm trying to find a new way of doing this.

    I'm sure there are some mistakes in my shader and people are free to look through it and make it better if they want.



  • here is an example of the physical surface node gone bad. I guess if you want to give the model tan lines this is how you would do it.
    0_1470864967404_PHyssurfacetrans.jpg



  • here is a little example of my cycles shader doing SSS on skin compared to EZSkin3.

    0_1470868247275_ES vs PBR 2.jpg 0_1470868260259_SS EZSkin_vs_PBR.jpg


  • Poser Ambassadors

    The comparison to EZSkin makes me wonder if you realize that EZSkin is not configured OPTIONALLY, but MANDATORY.

    Meaning - the amount of specularity is modulated and you have to decide how much to modulate it - it's not optional or automatic. Since it does not rely on specular maps, which almost nobody has, and even if it did, nobody has standards for, it uses the red channel of the skin texture, multiplied with a reflectivity value that HAS to be decided BY YOU.

    Shaders can't examine the image maps and calculate anything useful like what is the average brightness. So when I designed that shader, and Snarly created the UI for it, the presumption was that the user (YOU) would look on the resulting render and adjust the amplitude of the procedurally generated specular map, which as I said depends entirely on the brightness of the skin color map red channel.

    The reason I did this was because of what happens if I don't do this. You get skin-style specularity on the HAIR of the figure, or eye shadow, or other dark makeup. I can see it on your render where you used your shader. The eyebrow is reflecting light exactly as the skin is, which is impossible. I chose this approach (to mask off the hair) as the best compromise for people not capable or interested in going the extra mile and making true specular maps. The red channel seemed to be the best way to detect where on the color map is not skin, but rather hair or eye shadow or other surfaces that aren't skin and should not be shiny like skin.

    The consequence of this is that you really MUST adjust the amplitude of the specular reflections when using EZSkin. Note that you do this for the whole figure, and don't have to manually do it for each of the skin zones.

    If you go into the EZSkin UI and increase the specularity (sorry I don't recall which parameter that is in the GUI) you will see it can/would be much more than you're comparing to.



  • Hey BB

    Yes, I do try to edit the settings on ezskin to get get better results but not all functions are covered by the manual. The last time I read the manual (a couple of weeks ago) all I found was a short paragraph about playing with settings and seeing what looks good instead of an explanation as to what the controls do and why and what are typical settings for human skin.

    PLEASE don't take offense. I'm not trying to be a troll or an ass-hat. If I've offended you already, sorry for that, it was unintentional.

    My previous images did have even reflect over the entire figure and I new it was not right, just was deciding how I should fix it. in the next image here I'm using the bump map that I have modified (which I do to all my bump maps) so that the eyebrows are inverted (white) and the nostrils are the same flesh color and value as the rest of the nose.

    0_1470983590643_Cycles Skin 1.jpg



  • I forgot to say that I'm using the bump map to drive the roughness which is keeping the reflections in check.


  • Poser Ambassadors

    No worries, I did not for a second take offense.

    I wrote all that only because I've been meaning to for a while. I see quite a few people "complain" that the EZSkin results don't have enough specular, and the reason is they didn't tell it they wanted more specular.

    Your last render is much better -- I can see the difference in the handling of roughness.



  • @ghostship said in Dielectric Shader WIP for download:

    here is an example of the physical surface node gone bad. I guess if you want to give the model tan lines this is how you would do it.

    I'm not sure that this is necessarily a PhysicalSurface issue. Could you please check what the Visible in Raytracing property is set to for the options in question? If it's off, does enabling it help?



  • @Uli-Klumpp said in Dielectric Shader WIP for download:

    @ghostship said in Dielectric Shader WIP for download:

    here is an example of the physical surface node gone bad. I guess if you want to give the model tan lines this is how you would do it.

    I'm not sure that this is necessarily a PhysicalSurface issue. Could you please check what the Visible in Raytracing property is set to for the options in question? If it's off, does enabling it help?

    The reason for this is that with SuperFly specular is still active even with transparency set at 100%. Its the same with the PoserSurface root node. Simply set the specular color to black and the effect goes away.
    I am not sure if this is a bug or a feature at least it is different to the behavior of FireFly why i would consider it a bug.



  • @nagra_00_ thanks. At least we know what's going on with it.

    found an issue with my shader. I have the transparency pluged in backwards and the misspelled word that BB pointed out. I'll have that up soon with a new version.



  • I don’t want to discourage you from the work on your shader but believe me it is very very hard to beat the PhysicalSurface node. The roughness modulated fresnel of the PS node alone is hard to top and thats only one of its cool features.

    Well for FireFly there is room for optimization like a optional retrace mode for metals as with the current implementation metals are all black in an IDL only lighted scene… but thats another story.



  • @nagra_00_ said in Dielectric Shader WIP for download:

    I don’t want to discourage you from the work on your shader but believe me it is very very hard to beat the PhysicalSurface node. The roughness modulated fresnel of the PS node alone is hard to top and thats only one of its cool features.

    Well for FireFly there is room for optimization like a optional retrace mode for metals as with the current implementation metals are all black in an IDL only lighted scene… but thats another story.

    My shader does have a roughness modulated Fresnel.

    Have you tried unchecking "Reflection_Lite_Mult" and "Reflection_Kd_Mult" in the Poser root node on reflective materials? I never have a problem with reflective materials and IDL lit scenes in Firefly.



  • @ghostship said in Dielectric Shader WIP for download:

    @nagra_00_ said in Dielectric Shader WIP for download:

    I don’t want to discourage you from the work on your shader but believe me it is very very hard to beat the PhysicalSurface node. The roughness modulated fresnel of the PS node alone is hard to top and thats only one of its cool features.

    Well for FireFly there is room for optimization like a optional retrace mode for metals as with the current implementation metals are all black in an IDL only lighted scene… but thats another story.

    My shader does have a roughness modulated Fresnel.

    I just downloaded your shader and indeed it has, cool :-)

    Have you tried unchecking "Reflection_Lite_Mult" and "Reflection_Kd_Mult" in the Poser root node on reflective materials? I never have a problem with reflective materials and IDL lit scenes in Firefly.

    No, no, i was talking about using the PhysicalSurface node with PBR mats. In FireFly the PS does not use any ray reflection just specular which is usually Ok as it keeps render times low. Draw back is that with IDL only lightning metals are black as FireFly has no ISL.

    Meanwhile i played a little with the PhysicalSurface node and SSS. First time i did that and from my test render i can not recommend PS for SSS skin because it generates hard surfaces. Means the surface has hard shadows and that makes no sense on a soft SSS material. I have attached a pic that shows the effect. On the left i used a updated version of my SSS shader that i posted some time ago on RDNA.

    0_1471102415394_PS_SSS.jpg



  • I don't see that problem with the Cycles root but it doesn't render in Firefly.
    0_1471106022110_hand shadows.jpg




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