User Manual

Channel (Pixel) Variables
bga1..bga3 Background Alpha (for image1..image3)
vx1..vx3 X Vector (for image1..image3)
vy1..vy3 Y Vector (for image1..image3)
nz1..nz3 Z Normal (for image1..image3)
NOTE: Use c1, c2, c3 to refer to the value of a pixel in the current channel. This makes
copying and pasting expressions easier. For example, if c1/2 is typed as the red
expression, the result would be half the value of the red pixel from image 1, but if the
expression is copied to the blue channel, now it would have the value of the pixel from
the blue channel.
To refer to the red value of the current pixel in input 1, type r1. For the image in input 2, it
would be r2.
 get[ch][#]b(x, y) Read pixel at x,y, or 0 if out of bounds—e.g., getr1b(0,0)
 get[ch][#]d(x, y) Read pixel at x,y or edge pixel if out of bounds—e.g., getr1d(0,0)
 get[ch][#]w(x, y) Read pixel at x,y or wrap if out of bounds—e.g., getr1w(0,0)
NOTE: There are a variety of methods used to refer to pixels from locations other than
the current one in an image.
In the above description, [ch] is a letter representing the channel to access. The [#] is a number
representing the input image. So to get the red component of the current pixel (equivalent to r),
you would use getr1b(x,y). To get the Alpha component of the pixel at the center of image 2, you
would use geta2b(0.5, 0.5).
 getr1b(x,y) Output the red value of the pixel at position x, y, if there were a valid pixel
present. It would output 0.0 if the position were beyond the boundaries of the image
(all channels).
 getr1d(x,y) Output the red value of the pixel at position x, y. If the position specified
were outside of the boundaries of the image, the result would be from the outer edge
of the image (RGBA only).
 getr1w(x,y) Output the red value of the pixel at position x, y. If the position specified
were outside of the boundaries of the image, the x and y coordinates would wrap
around to the other side of the image and continue from there (RGBA only).
To access other channel values with these functions, substitute the r in the above examples
with the correct channel variable (r, g, b, a and, for the getr1b() functions only, z, and so on), as
shown above. Substitute the 1 with either 2 or 3 in the above examples to access the images
from the other image inputs.
Chapter – 100 Miscellaneous Nodes 2214