Smoothness (glossiness) from Substance has to be multiplied by 0.75 - is it always true?

Discussion in 'General Graphics' started by OskarSwierad, Mar 16, 2015.

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Dec 17, 2014
Posts:
25
As mentioned by Wes McDermott here:
"Unity still does a remapping of the smoothness map in their shader. This will result in Painter roughness being too smooth."
https://forum.allegorithmic.com/index.php?topic=4335.msg20602#msg20602

When is the flag UNITY_GLOSS_MATCHES_MARMOSET_TOOLBAG2 enabled?
Is it always true (just used as an ifdef for convenience) or does it change for some platforms / situations?

Code (csharp):
1.
2. inline half RoughnessToSpecPower (half roughness)
3. {
4. #if UNITY_GLOSS_MATCHES_MARMOSET_TOOLBAG2
5.    // from https://s3.amazonaws.com/docs.knaldtech.com/knald/1.0.0/lys_power_drops.html
6.    half n = 10.0 / log2((1-roughness)*0.968 + 0.03);
7.    return n * n;
8.
9.    // NOTE: another approximate approach to match Marmoset gloss curve is to
10.    // multiply roughness by 0.7599 in the code below (makes SpecPower range 4..N instead of 1..N)
11. #else
12.    half m = roughness * roughness * roughness + 1e-4f;   // follow the same curve as unity_SpecCube
13.    half n = (2.0 / m) - 2.0;       // http://jbit.net/%7Esparky/academic/mm_brdf.pdf
14.    n = max(n, 1e-4f);         // prevent possible cases of pow(0,0), which could happen when roughness is 1.0 and NdotH is zero
15.    return n;
16. #endif
17. }
18.

2. minhdaubu2

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Jun 10, 2014
Posts:
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Yeah, i noticed it today and it really annoy me, the solution in Allegorithmic forum doesn't seem to be enough.
Anyone has experiment to solve this problem?

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4. cakeslice

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minhdaubu2 and Jim-Boddie like this.
5. minhdaubu2

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Jun 10, 2014
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Should the Standard Shader add some "Rounghness intensity" control bar or an "Standard for substance"?

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Dec 17, 2014
Posts:
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minhdaubu2: Sure, a good fix, but in a long run - probably an unnecessary math operation and a confusing, app-specific setting

BTW, a quote from Wes:
http://steamcommunity.com/app/27339...0277373837/?insideModal=1#c618453594760401012

minhdaubu2 likes this.

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