curve

Software:
Maya 2018 | Arnold 5

An example of a basic traditional (not scanned) cloth material setup in Arnold 5 for Maya using an aiStandardSurface shader.

The shading network uses a classic angle dependent color blend to simulate the color of the cloth being washed out at grazing angle of view.

Explanation of the node graph:

1. A black and white fabric weave texture that will serve as input for multiple shading channels.
   * This is actually not the best example of such a pattern, and could be replaced with a much better texture.
   
2. A remapValue node is used to set contrast to the fabric pattern (reduce contrast in this case) prior to it being multiplied with the fabric colors.
   * Note that only one of the textures RGB channels is connected to the remapValue node since it’s a float (mono) processor and not RGB.
   
   * Note that depending on the fabric texture, you may have to design different curves to achieve the right effect.
3. Two colors are defined with colorConstant nodes:
   A deep color as the main fabric color, and a washed out color for grazing angle view (“side color”).
4. An aiFacingRatio node is used as an input for incident angle info.
   * Note that in this case I checked the node’s invert option to make it behave more like other systems I’m used to (if you don’t use invert, the angle blend curve in 5 will be different..)
5.  A remapValue node used to set the angle blend curve or in other words, how much does the color appears washed out per change of view angle of the cloth surface.
   * The longer it take the curve to become steep from left to right, the more the main color will be dominant before the washed out color will appear.
   
6. A colorCorrect node is used in this example just as a way to convert the remapped float value back to RGB for being multiplied with the cloth colors.
   * We could also connect it directly to the individual float components of the RGB colors but this way the node graph is cleaner.
7. A multiplyDivide node is used to multiply the processed fabric texture with the 2 fabric colors “baking” the pattern into the color.
8. A blendColors node is used to blend the 2 processed fabric colors together according to the processed facingRatio angle input.
   The result is the final cloth color that is connected to the aiStandardSurface shader.
9. An aiBump2d node is used to convert the fabric pattern to normal data that will be connected to the aiStandardSurface shader to produce bumps.
10. An aiStandartSurface shader serving as the main shading node for this material.
    * Note that under Geometry the Thin Walled option is checked so that the Subsurface layer of the shader will act as a Paper Shader rather than SSS.
    * The main cloth color is connected to the SubSurface Color input.
    

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