The Sheen tab is part of the V-Ray Mtl parameters.
Overview
Input Sockets
You can access these sockets, when you roll out the Sheen tab of the node. This section describes the input sockets of the node. They can be used to attach external nodes to determine these values.
Sheen Color – Allows a color node to determine the color of the sheen.
Sheen Amount – Specifies how much the sheen layer overlays the diffuse color. The higher the amount, the more of the sheen color you get. An integer-outputting node can controls this parameter, or the value can be set manually. See the example.
Sheen Glossiness – Allows a float node to determine the glossiness of the sheen.
Properties
Sheen Color – Specifies the color.
Sheen Glossiness – Controls the sharpness of reflections. A value of 1.0 means all of the light reaches the diffuse color, and when the value is smaller, the cloth material looks glossier. See the example. When the Use Roughness option in the Reflection tab is enabled, this parameter works as Sheen Roughness and controls the roughness amount (a value of 1 produces glossy reflections). When the Mode is set top OpenPBR, this property is hidden.
Example: Sheen Amount
This example shows how changing the amount of the sheen layer affects the material. Glossiness is set to 0.550.
Sheen Amount = 0.100
Sheen Amount = 0.500
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Sheen Amount = 1.0
Example: Sheen Glossiness
This example shows how changing the glossiness parameter of the sheen layer affects the material. The Sheen Amount is set to its default value.
Sheen Glossiness = 0.100
Sheen Glossiness = 0.550
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Sheen Glossiness = 0.900