Binary Alpha is a very simple, yet super convenient expression that I use all the time, and decided to turn into a quick gizmo.
It analyzes a choice of the RGB, RGBA, or Alpha input and outputs an Alpha Channel (or RGBA result) that is Binary, 0 or 1. Any Pixels that are not 0 will be turned into 1 (negative numbers also), and 0 will remain 0.
This is perfect for those “blur, unpremult, set alpha, blur” for tricks extending colors, or if you need a quick matte for finding any rgb color above or below 0, in a CG render passes for example.
The good ol’ blur/unpremult/blur ❤ :
The literal tcl expression is just:
r!=0 || g!=0 || b!=0 || a! = 0 ? 1 : 0
Which in english, translates to something like: “if red is not 0, or green is not 0, or blue is not 0, or alpha is not 0, then be 1, or else, be 0” So it will include negative pixels as an output as 1 as well.
Super simple but hopefully a time saver if you are like me and hate remembering expressions.
GradMagic is an interactive 4 point gradient tool, which can link to cornerpin nodes, and can toggle between live sampling from the plate or baking the color values of the corners.
Can be used for various tasks in prep and DMP,or if you just need a quick 4 point gradient map.
Quick Overview of the properties:
It’s pretty straight forward, heres some basic written steps:
1.) Set your cornerpoints manually or by pressing one of the ‘snap to’ buttons. Or alternatively you can link or bake your cornerpoints to an existing cornerpin node (or any node with 4 “to” knobs).
2.) If you need to adjust the points once they are baked/linked/ in place, then show the adjust knobs, set the reference frame to snap the adjust points near the main points, and you can then move each cornerpoint while it still retains its animation path.
3.) You can either keep the node live, bake the corner colors on a single frame, or bake the colors over a framerange. once baked you can adjust the cornerpoints further if you need to cover up more area. You can adjust the ‘sample size’ at the top if you want to average more colors under each corner point.
4.) Finally you can apply a blur to the edges to help with transition, and you can select the output at the top, whether to show the gradient over the BG input, or just the gradient itself.
Sorry for not posting in a couple months, I have been traveling and working. But I am ready to finish off this series. I think you guys will like this one because I go over some techniques on the IBK workflow. The first part of the video I show you a comparison between how I usually see IBK being used and the IBK stacked technique. There are 4 examples (a greenscreen, a bluescreen, a hair problem, and a shadow problem) that I go over and explain the concept of what the IBK is doing, and the importance of the IBK Color, or cleanplate.
Next I give you a step by step breakdown of how to setup this IBK stacked techniques by building these 4 examples from scratch. If you are already familiar with IBK and want to jump into the step by step process of this stacked technique, you can just to 7:09 (Step by Step process, example 1 greenscreen).
0:00 Intro 0:45 Comparison 1 greenscreen example 3:54 Comparison 2 bluescreen example 4:31 Comparison 3 hair example 5:53 Comparison 4 shadows and markers example
7:09 Step by Step process, example 1 greenscreen 17:12 step by step example 2 bluescreen 22:15 step by step example 3 hair and assisted eroding 27:37 step by step example 4 shadows / cleanplate customization 37:12 Outro
At one point, my cursor disappears in the recording. Something must have gone wrong during the recording process, but you should still be able to see me clicking and marquee-ing stuff.
I’m glad to be moving onto the despill section, as I think it usually is overlooked. In reality it’s just as important as the alpha, if not MORE important.