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Thread: Suspecting bug in clearcoat

  1. #31
    Registered User jbrookes's Avatar
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    I'm having similar issues with Principled and HDR Environment images.

    I found that dropping Specularity all the way down to between 2 and 2.5 helps (along with Roughness at zero and a Clearcoat setting of 3).

    Light Samples seem to help smooth out the hot spots (up to a light sample setting of around 48), but don't seem to help with the fireflies that crawl all over the surface during animations.

    There's no question that both Specular and Clearcoat are hyper-sensitive and blow out really easily. The above Spec and Clearcoat settings seem to help quite a bit with both the light source hot spots and the speckles/fireflies.

    Not at my LW workstation right now, but I'm pretty sure I have Subsurface at zero.
    Favorite Waves: LW3.5, 5.6c, 7.5, 8.5, 9.6, 2015.

  2. #32
    Registered User jbrookes's Avatar
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    Okay, I checked my settings and it turns out that my Subsurface is set to 5%.

    I tried raising it to 100% -- like for your settings -- and thinks got noisy really fast. Even 50% is pretty wild.

    So perhaps try something like:

    Roughness = zero
    Specular = 2.5%
    Spec Tint = 0
    Tint = 0
    Translucency = 0
    Flatness = 0
    Subsurface = 5%
    Distance = 10 cm (it's a 1m sphere in my case)
    Luminous = 0
    Metallic = 0
    Anisotropic = 0
    Clearcoat = 3%
    Favorite Waves: LW3.5, 5.6c, 7.5, 8.5, 9.6, 2015.

  3. #33
    Registered User jbrookes's Avatar
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    Last post from me for the night.

    Here's a couple that worked quite well for me:

    This one's sort of a semi-gloss (matte-ish) paint job:
    Roughness = 10
    Specular = 2.5%
    Spec Tint = 0
    Tint = 0
    Translucency = 0
    Flatness = 0
    Subsurface = 5%
    Distance = 1m
    Luminous = 0
    Metallic = 80
    Anisotropic = 0
    Clearcoat = 3%

    This second example is more of a glossy paint job:
    Roughness = 3
    Specular = 2.5%
    Spec Tint = 0
    Tint = 0
    Translucency = 0
    Flatness = 0
    Subsurface = 5%
    Distance = 1m
    Luminous = 0
    Metallic = 10
    Anisotropic = 0
    Clearcoat = 3%
    Favorite Waves: LW3.5, 5.6c, 7.5, 8.5, 9.6, 2015.

  4. #34
    Not so newbie member lardbros's Avatar
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    What are your SSS samples set to?
    The higher your SSS, the more samples you'll need too.
    LairdSquared | 3D Design & Animation

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  5. #35
    Registered User jbrookes's Avatar
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    So I took a look at this.

    lertola2/RebelHill's explanation covers the Area light. Indeed, unchecking Normalize appears to solve that one.

    I noted that the point light's reflection does decrease as the point light is moved farther away from the object. Whether it's decreasing as much as it should is up for debate.

    And as mentioned, the distance of the Distant Light won't make any difference. I did try playing around with the Distant Light's intensity and I got a reasonable reflection at around 0.001 to 0.005 lx. However, it isn't until the Distant Light it upped to 0.5 lx that you get enough illumination to match the illumination of the object's surface and the associated hotspot so that, together, they look realistic (IMHO). So I see what MonroePoteet is saying (at least for distant lights anyway). I suppose a workaround would be to twin up the Distant Light and have one that handles light reflections and another that handles diffuse surface illumination. The other option is to maybe avoid using distant lights?

    Anyone feel like doing a study at sunrise or of a sun setting over a mountain (armed with a mirror and a diffuse flat material) to see what the ratio of diffuse illumination to light reflection hotspot should be in real life?
    Favorite Waves: LW3.5, 5.6c, 7.5, 8.5, 9.6, 2015.

  6. #36
    there is no sanctuary....
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    Completely off topic. Is there a place to get these ‘standard’ models i see used everywhere? This dragon, Ajax, David etc. would be nice to have the same references.
    Bill Carey

    I7 6700K 4.0 ghz
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  7. #37
    Not so newbie member lardbros's Avatar
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    You can get some nice scanned models from here, statues, crabs and things:
    https://www.turbosquid.com/Search/Artists/oliverlaric

    The Ajax bust model can be found here:
    https://www.yobi3d.com/q/3D-model/ajax-jotero-com
    LairdSquared | 3D Design & Animation

    Desk Work:
    HP Z840, Dual Xeon E5-2690 v2, 32GB RAM, Quadro K5000 4GB
    Desk Home:
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  8. #38
    Registered User jbrookes's Avatar
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    I know the dragon's included with LW2018...
    Favorite Waves: LW3.5, 5.6c, 7.5, 8.5, 9.6, 2015.

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