Join Richard Harrington for an in-depth discussion in this video Adjusting motion blur, part of After Effects Guru: Faster Previews and Rendering.
I mentioned Motion Blur because it's the factor that impacts how an object blurs when it moves in the timeline. By default, Motion Blur is off, but it's one of those things that really improves the look of an animation. It also can really increase the render time. Let me show you a simple example. In this case here, I've got a composition, and I'm going to add a simple ellipse. And, with the ellipse selected, let's draw to create a simple shape.
There we go. I've got a circle shape layer. And, what I want to do is use the Anchor Point to have this bounce around. So, we're going to move that over, and up and out of the frame a bit. It's going to start there, then it's going to quickly come on down. You could do this with Position, as well. And then, bounce over to the side wall. Up a little bit. And, back off. Alright, let's preview that. Well, without any motion blur, it's moving through the scene, but it seems to strobe a bit.
If I globally enable Motion Blur and I hit Preview, again, nothing happens. That's because you have to turn Motion Blur on globally, for the composition, and then enable it locally, on the layer itself. Now, you're seeing that that adds a bit of a blur. In fact, if we zoom in here, you can see that more clearly. Let's look at that over black. As it's bouncing there, we get the streak. If you want to see more motion blur, have the object move more quickly.
And, we can do that by simply pulling these key frames closer together. If I hold down the Alt key and I drag, they will condense in. And, the motion blur is going to increase because the object is moving faster. See there? More motion blur. Well, let's really get this here, with a simple evolution of a spinning wheel. So, if I add a rectangle. I'll just move that over a bit. Put that near the center of the composition. And, let's use the Pan Behind tool here, to set the anchor point right towards the middle.
With that done, we'll do a quick, spinning rotation. I've got Motion Blur turned off initially. And, let's just do a quick spin. We'll tell that to do ten rotations. And, if I preview that, you see the classic wagon-wheel effect, where it seems to strobe, or you almost get a ghosted, echoing image. But, if we turn on Motion Blur for that layer. And, let's put that layer into full quality. You see that the motion blur now looks more photo-realistic, and that the edges are blurred more than the center, because the edges are spinning faster.
Let's increase the number of rotations there, to 30. That leads to more motion blur. And, we're seeing a wagon-wheel effect again, but with more of a streaked image. Now, if we go into the Composition Settings itself, under Advanced, you'll notice the Shutter Angle, and by default, 180 is the standard angle. This produces a natural sort of motion blur that most video cameras create. But, you can adjust this all the way up to 720 degrees.
Notice that the larger shutter angle produces more motion blur, a heavier streaking effect, while a smaller angle produces less. So, you might need to tweak that until you get the type of blur you're looking for. I generally find that I'm going to go somewhere between a 180 degrees and 360 degrees to get the natural type of blur I want. That's looking a little bit better to me, there. And, that seems fairly realistic. Just remember, Motion Blur is a complex setting.
First, you need to enable it here, globally, then you turn it on locally. Once that's done, under the Composition Settings itself, you can actually refine this a bit, as you see fit, just by adjusting the Shutter Angle, as well as the Phase. This has a little bit of extra ability. And, it impacted the way that that seems to be rotating. If you are satisfied with what you've done, that's great. But, realize that there is an important gotcha.
For example, I have a layer here, and you'll see that Motion Blur is not turned on. Well, perhaps I want to turn it on for only part of this, the animated logo. I'll step inside the animated logo and select the text layer, turn on Motion Blur, and enable it for that layer. So, as the text layer spins around, it picks up a slight blur. On the other hand, though, as I look at this here, everything seems about right. I could enable that for the layer itself, with the global switch turned on, but what I don't want to do is turn it on for every single layer out of laziness.
Doing that is only going to increase the overall render time. So, make sure you turn Motion Blur on for the layers that need it and leave it off for the layers that don't.
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- Creating render settings templates
- Using multiple output modules
- Setting processor usage
- Rendering multiple frames simultaneously
- Purging RAM
- Controlling your disk and media cache
- Creating and saving previews
- Controlling composition settings