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.
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)
|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|
|Image||Image||Image output of the effect|
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.
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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