Description

This effect replaces the color values of an input image by mapping each of its pixel according to it’s luma value to a second image used as ramp.

Each luma value is normalized from 0 to 1 and calculated by computing the values in the R,G and B channels.

The pixel luma values are then mapped to a ramp created using coordinates to define the Dark and Light point inside a second image. The color values found in the ramp replace the color values of the original input image.



Properties

  • Dark UV : The (x,y) coordinates of the dark point for the ramp.
    Default : (0.0 ; HEIGHT)
  • Light UV : The (x,y) coordinates of the light point for the ramp.
    Default : (WIDTH ; 0.0)

Inputs

Name Type Description
Image Image Image input on which to draw the effect
Ramp Image Image to be used as ramp to generate the effect
Light UV Vector 2D Coordinates for the light point of the ramp
Dark UV Vector 2D Coordinates for the dark point of the ramp

Outputs

Name Type Description
Image Image Image output of the effect

Example

To simplify the understanding of the node, in this example we are only changing the x value of the LIght UV vector which defines the color to use for the lighter parts of the image.
This x value is simply slid horizontally along the image used as a ramp on the topmost line of pixels.




In this example :

  • Light UV : X value is animated using and LFO between 600 and 1800 and Y value is static at 0.
  • Dark UV : X and Y values are both 0.

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