Create Mask Icon

asCreateMask

A node that allows the user to create a greyscale mask of a input color or texture.


Parameters


Color Parameters

Input Color
The color used to create the mask from. It’s expected to be scene-linear.
Input Alpha
The alpha channel of the color used to create the mask from.
Threshold Channel

The channel to use when applying a threshold in order to build a mask. It can be one of

  • Red
  • Green
  • Blue
  • Alpha
  • Hue
  • Saturation
  • Value
  • CIELAB L* [1]
  • CIELAB a*
  • CIELAB b*
  • Average
  • Luminance [2]
Threshold Value
The threshold value to apply to the channel chosen.
Threshold Function

The function to use for the threshold. It can be one of

  • None
  • Step
  • Linear Step
  • Smooth Step
  • Exponential
  • Double Circled Seat [3]
  • Double Circled Sigmoid [4]
  • Smoother Step [5]
  • Smoothest Step [6]
Threshold Contrast
The contrast to apply when the function is Double Circled Seat (a contrast flattening curve) or Double Circled Sigmoid (a contrast increasing curve).
Threshold Lower Bound
The lower bound for the smoothstep, smootherstep and smootheststep functions.
Threshold Upper Bound
The upper bound for the smoothstep, smootherstep and smootheststep functions.

Outputs

Result
The new mask.

Screenshots

Some examples showing some of the masks created with the modes outlined above.


Footnotes

[1]CIELAB or CIE 1976 L*a*b* color space.
[2]For this this assumes the input color is using the ITU-R BT.709/Rec.709 RGB primaries. Once support for working or rendering space using other primaries other than Rec.709 is added to appleseed, this will be extended.
[3]A contrast flattening function, see Double Circled Seat function.
[4]A contrast increasing function, see Double Circled Sigmoid function.
[5]A smoother smoothstep function, with 0 first and second derivatives at x=0 and x=1.
[6]Like smootherstep, but with 0 third derivatives at x=0, and x=1.