Join Steve Wright for an in-depth discussion in this video 065 More about time, part of NUKE NUGGETS Weekly.
- [Steve] Hi, this is Steve Wright welcoming you to this weeks Nuke Nugget, It's About Time, part two. Last week in episode 64, we took a look at some of Nuke's many time nodes, so this week, we'll finish the rest of them. We'll start with the TemporalMedian node. Now what it does is it performs a median filter between frames. Normally a median filter is used within one frame and performs the median filtering operation between adjacent pixels, in other words, it's a spacial filter.
But here we're going to go between frames, and that makes it a temporal filter. So it's actually an early primitive Denoise node, if you will. And you open this guy up. If I push in here, and we look at our blue screen, this is a really noisy blue screen, I'm going to disable the node, and you can see my green coming back, so I'm going to enable and disable. So you can see how it's done a bit of a degrain on my blue screen. However, this is the problem with a TemporalMedian filter, anything that's moving will also get clobbered.
So if we look over here, these are moving, so if I go step forward and backward, you see I got some artifacts here which are not pretty. Okay, so the lesson about the TemporalMedian filter node is don't use it. Use Nuke's Denoise node. All right, let's cruise on down here and take a look at TimeEcho. Right, we'll hook up our viewer, rehome, playhead to frame one, and open up the TimeEcho node.
So the TimeEcho node blends back frames to the current frame. How many frames to look back is set right here. So I've set this to 10. Now it's going to look backwards 10 frames. With the playhead on frame one, there's nothing to look back to. Frame two, three, four, five, six, seven, eight, nine, 10. Now it only looks back 10 frames, so if I keep going it's going to erase the frames at the back.
Okay, they will always be just and only 10 frames. Now if you want to have a fade out at the tail end, you add a fade out here. Let's say I want the last five frames to fade out there. Okay, so it will always show me 10 frames fading out nicely at the end. Again, this is just a printing of the previous frames. And you get to choose three methods of combining. By default it's Max which looks like this, but you could use Plus where they're added together every frame, or Average where they're averaged together.
Okay, so that's TimeEcho. Cruising on down here, oh, TimeBlur. Okay, let's take a look at Mr. TimeBlur. Took my playhead to frame one. Now the TimeBlur node does a motion blur thing. Okay, so let's open up this TimeBlur node. It was intended for when you've tracked like a garbage man on something and it's whipping across the screen, you can apply a motion blur using the TimeBlur node.
So I'll step through that. Now without it, you see I got absolutely no motion blur at all, but with the TimeBlur node it adds motion blur. How much you get is how wide your shutter is. So if I say I want my shutter to be three frames, I'm going to get a lot of motion blur. But that helps me show you the divisions. That's how many stamps you're going to get. So the more divisions, the higher the quality. Of course, the greater the compute time, right. Okay, now also, FYI, the Roto node itself has a TimeBlur feature, if you will.
So if we go to the Motion Blur tab and set it for global, then the Roto node is going to introduce the TimeBlur as well. So there's a couple of options if you're trying to add motion blur to your Rotos. But now let's look at a clip. Here is this little clip here which has this little character animated like that. What happens if we put a TimeBlur on that? A big nothing, okay.
In fact let me open the shutter up to three frames, boom. The problem is it is just stamping the previous frames. It's not doing anything clever. However, in this case here, here we go, let me know where it's at. Okay, now this is the same action. The difference is the character is getting its motion from this Transform node right here. So if I open that up, you can see there's my path of motion.
See the nice arc, okay. Now if I do a TimeBlur on that, look what I get. Do you see the arc? So here's what's going on with TimeBlur. It's looking upstream at the transform motion. So it is seeing the path of motion and giving you interpolations in between your key frames. If I have the shutter set for three, so it's like holding it open for three frames, which is huge and silly.
I just wanted you to see how it worked. And then we put in more divisions and we get smoother and smoother motion blur, of course. I'm going to put that back to 10, 'cause I want to show you this, a comparison between the TimeBlur and TimeEcho. Okay, punch up TimeEcho. Now TimeEcho is also doing several frames, but the difference with Mr. TimeEcho is he is not looking at the transform curves, he is not doing any in between frames for us.
So TimeBlur actually looks at the transform data, and that's how it makes all those nice in betweens that follow the true path of motion. Now we also have the NoTimeBlur node. So we'll go up here, and we'll go find Mr. NoTimeBlur. Okay here's the story on that guy. When you use the TimeBlur node, all the way up to the Read node, it's asking for multiple frames and that can be rather time consuming and slow down your comp.
So what you can do is insert the NoTimeBlur node upstream, and it'll prevent the TimeBlur request from going to the nodes up above, and that will help speed up your comp. Okay, last, TimeOffset. Okay, we'll hook up our viewer. We home the viewer, jump to frame one. Now what TimeOffset does is it shifts the clip in the timeline.
We saw we could do that in the Read node, but sometimes you might want to do this down in the middle of your comp, not necessarily up at the Read node. Let's say you got a branch and you want to shift the timing of the clip five frames to do some sort of a thing. So this shifts the clip in the timeline. Let me open up TimeOffset, and I'll set it for 10. And now, when I pull forward, you'll notice that my timeline is actually changed.
I don't know if we saw that. Let me take that out. Notice the default timeline is one to 80, so this is an 80 frame clip. Once I hit the TimeOffset, with 10 frames, it has shifted the timeline for me. Again, only if you have it on Input. If you have it on Global, you won't see this. So I can also see this in the Dope Sheet. There, I've shifted my time by 10 frames.
And off we go with the clip shifted to start on frame 11 of the timeline. Now we can shift the clip in the other direction by putting a negative number here. There you go. And we can see in the Dope Sheet which way it has shifted. You might find it helpful to use the Dope Sheet to see what's going on when you're first setting this thing up 'cause it can be confusing. Does negative go left or right? Does that make it sooner or later? I don't know. So we'll just check it out on the Dope Sheet. Okay, all right, now let me clear that out and show you the last feature which is reverse print.
Let me home my viewer, clear this to nothing. There we go. All right, so my timeline is all set, back to default and normal, right. Timeline frame one, clip frame one. But reverse print will flip the clip and play it backwards. You can't do that in the Read node. Okay, and the other thing to know about TimeOffset, it also works with 3D. There's a 3D sphere here, a little animation going here.
Check that out, zing, zing, zing, zing, zing, okay. If I put in a TimeOffset of let's say 10 frames and then hook up to the TimeOffset node, my CG animation shifts by 10 frames. So TimeOffset affects 3D as well. Okay, over here is the TimeClip. Okay, the TimeClip node. What the TimeClip node does it allows us to trim the clip, shift it in time, and do a reverse print.
We open that guy up. And the first ting you'll notice is all these controls are duplicated in the Read node. Here's the same frame range here, the frame popup expression there, and the original frame here. So the TimeClip is an older node and they wound up incorporating all that in the Read node. However, there's two things in here you won't see in the Read node and that is the reverse print button and the fade in, fade out. So I could add a 24 frame fade at the head and a 24 frame fade at the tail, and then we'll play.
And we get near the end and fade out, done. Okay, so TimeClip is a good place to go to add fade ins and fade outs to your clips. And if you want to do it reverse, you can do that too. Well, we've run out of time, so there you have it, all about Nuke's time nodes. If you'd like to see all my Nuke courses on LinkedIn's lynda.com, just do a search on my name, Steve Wright. Be sure to check in next week, so you don't miss out on my next Nuke Nugget.
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