Join Ian Robinson for an in-depth discussion in this video Using Timewarp with Motion Blur, part of Mograph Techniques: Retiming and Tracking Footage.
In addition to being able to re-time your footage, you can also control the motion blur directly within the effect of Timewarp. So to show you what I'm talking about, let's jump to the comp 02_Jump. To apply our Timewarp, of course we need to add an adjustment layer. Now let's apply our Timewarp. We'll go to Effect > Time > Timewarp. Now immediately Timewarp is going to default to the Speed setting. This time I'm going to be really precise about what frames I'm working with.
So, let's change that speed to source frame. Now, if you scrub through the timeline after the setting notice nothing's going to move in your footage. That's because the source frame is set to zero by default and it just stays that way. So we need to press Home to move our current time indicator to the start of the timeline and add a keyframe for our source frame. And then press N and go down and look at our time indicator to see, okay that's 90 frames. So let's change our source frame value to 90 frames. Now if you press U on your keyboard, we can see the two keyframes we've created. And if we open our Editor, you can see the line that's been created. This is just like when you enable time remapping on any sort of layer. Now let's move our current timeline indicator to around 203. This is where I want the time change to happen. So in order to do this I'm just going to add a keyframe at the current value. Let's go to the left side of the timeline and click our diamond keyframe button. Now before I make this change I want to add some buffer keyframes so move your current time indicator further up the timeline towards the front. Let's say around 120.
Then add another keyframe. Then, we'll move back down the timeline to around 2:12, and add yet another keyframe. Since I have these two buffer keyframes, I can now make adjustments to that extra keyframe we first added. No matter what setting I change this keframe to the timing after and before will always remain the same. Now let's move our current time indicator diretly over our third keyframe here. Notice as I move up and down I'm getting a unit number and even through its not a square number let's see its set at 2961.
OK well let me change this to 29. That means this frame is exactly frame 29. If we move our current time indicator to frame 29, sure enough, absolutely no change. So again, this is a very precise way of adjusting your retime effects. Now just like any other key frame, we could ease this out, so let's do that. I'll right click on the key frame, go to the key frame assistant and choose easy e's, and with our control handles we could control the amount or the speed in and out of our key frame.
So that's all well and good everybody understands how to retime. But, let's move our current time indicator to around 123. Now, let's go to Timewarp and scroll down in the effect controls. Go ahead and enable motion blur. It may take a second to process but, now notice I've got some great motion blur on our footage. Now, if you want to create some kind of crazy effect, you can increase the number of Shutter Samples. So, this will give it some really really nice smooth blurs. It's increasing the number of frames to create the blur. So, the higher the number the more the processing but, also the smoother the blur in general.
Let's see what this looks like. I'll load up RAM preview and make sure I start it from the beginning. Once you've gotten through the time change go ahead and press the Spacebar and see what we've got. I don't know about you, but I think that's kind of cool. Now, I'll stop playback here and just tell you one more thing about Timewarp. After we apply the motion blur, if you ever want to speed up your system, and not have it take so long in that process, you could change the method from Pixel Motion to Frame Mix. This won't give you quite as smooth of a blur but it will speed up the overall processing.
- Analyzing a rough cut
- Tracking with mocha
- Adding and animating spheres
- Creating an animated logo with particles
- Adding dynamic motion
- Color correcting the back plate
- Blending particles emitters
- Retiming layers with prerenders
- Adjusting speed with Timewarp