Notes

Inputs

A: Asset in front

B: Asset in back

Operation/Modes

💡

TIP: Once an operation has been selected from drop-down menu, using the up/down keys can cycle through the list to visualize each of their impact in the Viewer.

Math operation key

A: A input image

B: B input image

a: Alpha channel of the A input

b: Alpha channel of the B input

1: Constant of White

Visual Reference

Guide: https://www.youtube.com/watch?v=QwFPd_nF2uM&ab_channel=SenecaVFX

Merge Operations

Open topic with navigation When layering images with the Merge node, you need to select a compositing algorithm that determines how the pixel values from one input are calculated with the pixel values from the other to create the new pixel values that are output as the merged image.

learn.foundry.com

Over

A + B * (1 - a)

Merge using the alpha channel

Plus

Merges without looking at alpha channel

Brings in more highlights than Screen mode

Max

Setting to be used for merging Rotos to verify that alpha values do not go over 1.0.