From the course: VFX Keying: Master Course

Unlock this course with a free trial

Join today to access over 22,400 courses taught by industry experts.

Improving edges with an AddMix comp

Improving edges with an AddMix comp - Nuke Tutorial

From the course: VFX Keying: Master Course

Improving edges with an AddMix comp

- [Teacher] Using the AddMix node for the actual composite adds another level of edge control which is good. However, it's a global solution, so whatever you do to fix one edge will be applied to all of the other edges whether you like it or not. Well, let's start by seeing how the AddMix node works. So I have a little setup for you here. I got a green screen. I did my spill suppression. I brought in my key. You can see it right there. And here's my background. I've got it on this little toggle guy, so I can change backgrounds real quick. And we bring in the alpha channel. So I have the alpha channel also behind the background. So, let's push and I've mocked up the internal workings of an AddMix node for you. So, here's our foreground layer with the alpha channel, and then we send that into a premult, and that's exactly what we expect. Now, here's the background layer. It has the same alpha channel. So when we do the premult, we get the wrong thing because the polarity of the alpha…

Contents