Sheen - Link to Albedo?

Questions
1

Sheen with “Link To Albedo” looks unexpectedly dark when Metal is zero, but it looks OK when Metal is one. Does anyone know why this is the case?

Using a solid color seems to always provide better results than Link to Albedo.

The fabric in this example has two material variants:

  1. The first variant uses 100% metallic fabric, so specular reflections are colored similarly to how satin reflects lighting:

    sheen-testing_all-metal-fabric_babylon-js-sandbox
    sheen-testing_all-metal-fabric_babylon-js-sandbox879×538 458 KB

  2. The second variant uses a metalness texture to assign the gold threads as metal and the purple threads as non-metal:

    sheen-testing_metal-mapped-fabric_babylon-js-sandbox
    sheen-testing_metal-mapped-fabric_babylon-js-sandbox879×538 486 KB

The all-metal example is a non-physically accurate use of metalness (satin is not metal), however it seems to reflect lighting more like real satin. The non-colorized reflection in the second variant does not properly replicate the look of satin; the fabric looks more like plastic.

Real-world satin brocade examples for reference:

chair_damask_purplegold_all-metal-fabric.zip (2.0 MB)

chair_damask_purplegold_metal-mapped-fabric.zip (2.0 MB)

2

link to albedo was a first implementation of the Dassault GLTF proposal and was overdarkening the base. I or Someone from the community (I would love that actually) and yes @Evgeni_Popov I am thinking about you :slight_smile: cause of what you did on CSM !!! need to integrate this proposal : https://github.com/KhronosGroup/glTF/pull/1688 basically a separate roughness and an albedo correction to solve all the issues we are currently exhibiting here with a none accurate setup to look natural.

Let s see if someone can do it, else I would unfortunately not be available before March on this one :frowning:

I am sorry in advance for the wait.

3

I need to finish dealing with the scroll viewer, but yes that’s something that looks interesting :slight_smile: (I would have first to learn a bit of PBR, though).

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4

Ohhhhh mannnnnn !!! I can tell you in a quick meeting all you need to know and this would be amazing :slight_smile:

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