Join Steve Wright for an in-depth discussion in this video Keying the zombie, part of NUKE Compositing: Zombies.
So in our first Nuke script, we'll take a look at our input clips right here. Project Settings, typing s on the keyboard, shows that we're already set up for our 242-frame shot, and our full size resolution is already secured matching the background plate. You'll notice the green screen is a little oversized. That's because we're going to be doing a push-in, so we need some extra pixels there. So I'll close the Project Settings and open up the Read node to show you that both of these clips use relative addressing.
So if you move the new script somewhere, you're going to have to reconnect the media. Alright, so let's get started. The first thing we got to do is shift the timing of this guy. This is a 242-frame shot, but we look here, we have 137 frames of zombie. That's because he doesn't pop up until around frame 100 or so. So we need to shift him in time. So we'll close this Read node, select the Read node here and pick up a TimeOffset and set it for 105 frames.
Now he pops in the middle of the shot, and he ends right at the last frame. Perfect. Okay. Next, we're ready for our Primatte Keyer. I'll select the TimeOffset, going up to the Keyer tab and select the Primatte Keyer. Let's move this guy over here because we won't be working with him for a while. Focus on this. Now this course does not teach the Primatte Keyer. If you'd like to bone up on it a bit, look in my Nuke Essentials Training course, Chapter 10, Keying.
The reason I chose Primatte is it's more forgiving of an irregular background. So let's pick a nice frame and take a look at how we might do this. I'm going to start by doing the Auto-Compute. Primatte's Auto-Compute does a very nice. We'll switch the Viewer to the Alpha channel, and I'm going to clean the background noise holding down Shift and Command or Control. Now we're going to do a little Gamma slamming, so I going to pull up on the Viewer Gamma to check for any noise in the background.
We got some stuff here but I'm not going to adjust Primatte to get rid of it because that'll harden my matte. I'm going to be using a Garbage Matte, so we'll just leave that right where it is. Next, I need to clear out our green box. So with Clean BG Noise selected, I'll do a Shift, Command or Control to clear that out. Now I've introduced some transparency, and again, some Gamma slamming so we can see better. So I need to fix that. So we'll come back in here and clean the foreground noise, select him, tighten him up, looking for any transparencies.
Alright, then we'll go back and check for our background. Okay, now this is no problem because, again, I'm going to Garbage Matte this guy in our very next movie, so I'm not going to worry about this stuff out here. I just want to worry about my close edges. So let's get in here and Gamma up to look for the noise. And let's do one more Clean BG Noise. We'll just click along here, see if we can't get some of this stuff cleaned up a little bit...
without introducing any serious transparencies in our character. Okay, rehome the Viewer. Gamma down looking for holes. Looking good. So we'll put this back to Default, and switching the Viewer back to RGB, I'm going to set Primatte, Output to do the not premultiplied, the original green screen. Because I'm going to be doing my own spill suppression, color correction, and edge sweetening, I don't want Primatte doing that for me.
I'm just going to be using Primatte's Alpha channel. Okay, in our next video, we're going to clean up this Alpha channel and get ready for our Comp.
First you'll learn how to apply a quick key with Primatte, and enhance the zombie with realistic blood, red eyes, and fangs. Then, turning to the graveyard plate, you'll make a day-for-night color correction and add interactive lighting. Finally, you'll composite the key, plate, and effects and finalize the shot, using color correction and a push in effect. The process is broken down into easy-to-watch five-minute videos, rich in valuable VFX production techniques from compositing guru Steve Wright.
For more training on the basics, see NUKE Essential Training..
- Keying the zombie
- Adding a garbage matte
- Adding effects
- Turning a daytime shot into a nighttime graveyard
- Adding interactive lighting effects
- Compositing the zombie
- Applying final color correction