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Tracking and layers: a gentle start
HitFilm guru Simon Jones shows us how to build a dramatic shot in HitFilm using layers of stock footage we provide on the course. Enjoy your 'comping'
Welcome to the first week of Future Learns Visual Effects for Guerrilla Filmmaker’s course. My name is Simon Jones. And I’m going to be guiding you through your first visual effects experiments. Now this week, we’re going to be starting off with something nice and simple to teach you about the core concepts behind layer compositing. Now most of you are filmmaker’s already, which means you’ll be familiar with traditional track based editing. That’s when you take a series of clips and you put them one after another in a sequence to create the edit of your film. Compositing is slightly different. With this we’re dealing in layers. And you stack layers on top of each other.
It’s a bit like having a stack of paper that you then look at from above. And by combining these layers together, and cutting holes in them, and moving them about, you can create entirely new shots. This is the shot we’re going to be working on. The flare is an entirely composited element. Here’s the original shot for comparison. Using visual effects for this has many benefits. It means that you don’t have to worry about the flare suddenly running out halfway through the shot and messing up your actor’s performance. The actor himself doesn’t have to worry about holding something really hot close to his body.
And actually it makes it easy for your director of photography because he can light the scene without having this random chaotic element in the shot. I’m going to be using HitFilm3 Express which is a free editor and compositor. If you haven’t installed HitFilm already, do so now. The techniques we’re using apply to any kind of compositing software. So if you have other software you’d prefer to use that’s totally fine. And you should still be able to follow along with the tutorials. There’s a project file you can download for this lesson. Once you’ve downloaded and unzipped the files, double click the flare project to open it up in HitFilm. You should see something like this.
If your interface looks noticeably different first head up to the workspaces menu at the top, open it up and select the compositing layout. You can customise your interface as much as you want. And you can always come back to the workspaces menu if you need to go back to a standard layout. At the top right is our viewer, which shows what we’re working on. Down below is the timeline where we assemble our layers. On the left is the controls panel. And if you select the video layer on the timeline by clicking on it, you’ll see some of its properties appear in the controls panel.
And in the middle we have the media panel where all your videos, images, audio, and other assets are stored. I’ve already set up the project with the video on the timeline. If you hit the Play button on the viewer you can see what’s happening. There’s some movement on the end of the flare which is where we want our flame to sit. We’re going to track this automatically to save some time. So click the little white pointing arrow on the timeline next to the video’s name. This expands it to reveal more details. Next to where it says tracks you should see a plus icon.
If you can’t see it just widen the track listing a little bit by dragging the divider with the mouse. Clicking this adds a new tracker to the layer. Up in the viewer you’ve now got a couple of coloured squares. And we use these to tell HitFilm what to track. Use the zoom menu at the bottom right of the viewer to zoom into 100%. You can now move around the frame using the middle or right mouse buttons. Click anywhere inside the squares to display their controls. We now need to move them over the tip of the flare prop.
So put the mouse inside the red square but without highlighting that centre point, and then click and drag to move both squares over the tip of the flare. Now we’ll drag out the corners of the red square so that it covers the shape of the flare tip. This red shape tells HitFilm exactly what to look for while it tracks. The green shape, meanwhile, tells HitFilm what area to search in for the red shape. The faster the movement you’re tracking, the bigger the green shape will need to be, as HitFilm film will need to look in a larger area on each frame. In this case, the flare isn’t moving very much so we can actually keep the green shape pretty tight.
Up in the top left you’ll see the track controls. All we need to do for now is hit the forward track button, which is the right pointing triangle. HitFilm will track through the shot. It should only take a few seconds. In the viewer you’ll see the tracking shapes moving around with the flare. If you drag the playhead around now you’ll see that you have a perfect track. Now you could’ve animated that movement by hand but using tracking makes everything faster and easier. When it comes to visual effects if you’ve got a technique that will take less time and still look good then that’s the one you want to go for. We’re now going to create something called a point layer.
To do this, click the new layer button on the timeline. And then select point from the menu. Make sure you also switch back to the viewer, which you can do using the tab at the top of the screen. Point layers don’t show up in your actual video. Instead, they’re used as references and are very useful for positioning multiple layers at the same time. Currently our point layer is just sitting in the middle of the frame. What we need to do is apply our tracking data to this point layer. So click on the tracker on the timeline to display its information again. We now want to apply the tracking data on to the point layer that we just made.
So in the track panel, find the layer menu, and then select new point, which is the point we just added. And then click the apply button. If you now select the new point layer you’ll see that it’s locked right on to the end of the flare prop and is animated as you move through the video. We can now attach other layers to this point and they’ll also be tracked on to that same movement. In the media panel find the flare video. Click and drag it down onto the timeline. You’ll see a blue crosshairs showing where the layer is going to be positioned. Position the mouse above the actor layer in the list and then drop the new clip.
The flare layer is now on top, which is why we can’t see the actor layer. Click and drag anywhere in the viewer and you can move that flare layer around revealing the actor underneath. Clips like this are called stock footage. These are generic videos which could be reused in multiple projects. Sometime stock might be location shots of places that you can’t physically get to. Or it might be a pyrotechnic visual effects element, like this one. We’re going to use our tracked point to position the flare. Make sure the flare layer is selected on the timeline. Then switch to the controls panel. Click the right pointing triangle next to transform to open up the options. All layers have an anchor point.
By default, this is in the centre of video layers. But we’re going to move it so that it sits on the base of the flame. To do this, click and drag on the numbers for the anchor point setting. I found that settings of about minus 115 and minus 500 worked well. You can also click on those numbers to type them in directly. OK. So now that we’ve got the anchor point at the base of the flame, it means any alterations we do to the layer’s position or rotation are based around that anchor point. We’ll now link the layer to the tracked point.
To do this, click the menu that currently says none just to the right the flare layer’s name, down on the timeline. Choose new point. At first nothing seems to happen because the layer is now offset from the tracked point. Back in the layer’s transform options, change the position settings to zero and zero. This means the layers anchor point will be right on top of that tracked point. Move the playhead and you’ll see the flame is now locked onto the movement of the prop. So the next thing to do is remove the black parts of the video. This is actually very simple. Open up the layer properties and go to the blend menu.
All of these different options change how the layer is blended with the layers below. Normal blends means that it’s simply placed on top. We’re going to change it to screen which causes darker areas to disappear while the brighter areas remain. This looks pretty great, straightaway. But we do need to do a little bit of tidying up. For the moment, just select a different layer. Such as the new point layer. If you look closely in the viewer you’ll see that you can actually detect the edge of the flare layer. This is because those parts of the frame weren’t actually fully black. To counter this we’re going to use our first effect. So switch up to the Effects panel.
Here you’ll find a huge library of effects for use in your projects. Open up the colour correction folder and find the crush blacks and whites effect. Drag it from the Effects panel down onto the timeline and drop it directly onto the flare layer. In the controls panel we can now change the behaviour of this effect. Increase the black point just a little, to about 0.05. This clips the darker areas, slightly increasing contrast, and removing the visible image from the layer. We now have a very convincing flare effect. At this point, it’s worth highlighting how important the practical onset lighting is for the success of this shot. Check out this alternative version without any of the flickering red light.
It’s nowhere near as realistic. Always try to plan out your visual effects shots in advance so that you can incorporate practical elements on set. Combining computer generated elements with practical real stuff keeps your audience guessing. OK. So we’re not quite done. It’s pretty rare that a vision effect shot will only have a single layer. Shots will always benefit from additional detail. Switching back to the media panel you’ll find another clip called sparks. Drag this down to the timeline above the flare layer. We’ll use the same techniques as before. Change the anchor points in the transform settings so that is over where the sparks appear.
And then we’ll link that layer to the new point using the parent menu on the timeline. Then we’ll go back into the layers transform and zero out the position. You can now see the benefit of using that point layer. It makes it really easy to attach multiple elements to that one position. Up in the layer properties we’ll change the spark clips blend mode to add. This creates a more intense blend than the screen mode. We want to do the same trick with the crushed blacks and whites effects to get rid of the physical edges.
But rather than doing it from scratch, this time display the menu for the crushed blacks and whites effect that’s already on the flare layer and select copy. Open up the sparks layer and then select paste from the effects group menu. This adds the effect with the settings already in place. We want these sparks to go straight up. But they were filmed going sideways. This is an easy fix. Simply use the rotation setting in the transform controls. Because we moved the anchor point it rotates around the correct pivot point. Know that you can also rotate layers using the blue square in the viewer. They layer is also a bit too big, currently. So we should drop the scale down, that’s all.
You can do this in the controls panel or by dragging the edges of the layer in the viewer. Congratulations. You just made your first composited visual effects shot. Now although this was a simple beginning, the concepts we’re talking about will actually take you a really long way. Everything we do will build upon what we’ve talked about today. So you know, now, how to track and how to composite layers together. Have a think about films you’ve seen recently. Can you think of any shots in them that must have used these techniques? OK. So next week we’re going to be talking about green screen, which opens up all kinds of extra possibilities. In the meantime, thank you for watching.
And let us know how you get on in the comments.
This week it’s all about understanding the essentials. Most visual effects artists start out with compositing layers, which is how creative tools like HitFilm and After Effects work.
This involves combining multiple layers of videos and/or images to create a brand new shot, or to alter an existing shot. Layers can be moved about and resized, or you can cut holes in them to reveal layers below.
In our first practical exercise we take a look at the fundamentals of working with multiple layers.
We also introduce the concept of tracking, which is used to automatically follow movement within a video. There are many forms of tracking, and they will save you hours upon hours of project time.
Project files
Download the ZIP file at the bottom of this page which contains the video assets and HitFilm project file for this tutorial. Be patient though, depending on your internet connection it could take a while, but it’s worth it! Return to Step 1.6 to download and install the HitFilm software if you haven’t already done so.
Let us know how you get on in the comments!
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