ShotANVIL: Basic Concepts (Tutorial)

Hello and welcome to another CoreMelt ShotANVIL video. This tutorial will go over the basics of how a ShotANVIL setup is structured in terms of Layers, Tracks, Brush Strokes, Shapes, Effects and Masks, and how to use them to modify the built in effects to get better results.  It is these components combined together which make a specific ShotANVIL effect template, aka plugin.

So let’s start with this effect here, called ShotANVIL Blank, which, as it sounds, is just a starting point with no effects applied.

Drag it to a clip on the timeline, and open the ShotANVIL editor. What you have as a default is two layers: the Source Layer, which is locked by default, and an initial Track Layer, which, at its most basic, will contain one mask and one effect.

As we shall see later, additional Track Layers containing other components can also be created and tracked to match the motion of other parts of the source clip.

Each track layer will modify the original source clip by applying its effect, limited by any masks on the track layer.

For those familiar with Apple Motion, this is similar to the way groups and hierarchies work in Motion except that in ShotANVIL, a Track Layer, and the components contained in it, can only have a single, shared tracked motion.

Everything inside this folder called Track Layer 1 will move according to the same tracked motion.

In terms of compositing  ShotANVIL layers function like adjustment layers in After Effects, Photoshop, Motion or other graphics apps, in that it will apply the components in the Track Layer to modify the pixels in the layer below without having an explicitly duplicated source in the layer itself.

TITLE: MASKS + EFFECTS

Okay, so first of all, let's add a starting mask into Track Layer 1, hit enter.

Nothing changes yet, because there are no effects or graphics within the layer yet - it is just showing the un-modified pixels from the unmodified Source Layer. So we wouldn't actually expect a visual result.

Let’s have a quick look here at these menus. They contain the individual Effects and Masking Tools which are what allow us to add new effects and new masking tools.

The Presets sub-menu is for user-defined presets.  Since we are starting from scratch, there aren’t any stored here yet.

Then there’s

• color correction tools
• blur and sharpen tools
• Stylize, and
• utilities.

So let’s start by adding the standard color correct effect. 

Now again, that's not changing the image yet, as the parameters are all at their default values and so do not change anything. 

As soon as we adjust the Hue parameter, we can see the change. Play with the RGB a bit, and toggle the Color Correct effect on and off to quickly see the difference. 

Importantly, we can now see how the shape mask is limiting the area of the effect within Track Layer 1.

ShotANVIL contains a powerful image channel viewer to see specifically how the masks and effects are modifying specific channels of the output.

In the Result (aka View Channels) menu, we have the options to view:

• Source
• Result
• Red, Green and Blue
• Mask (aka Matte/Alpha)

Select the Mask channel. At the moment, it shows all white, but if you click here, enabling the eye icon will show you the output of that particular mask. If we go to the element list, and click to the right of the mask element, you can see that the mask applied to the Color Correct component visually shows its effect.

If we click on Track Layer 1 itself, the mask is all white because it's passing everything below as a result. 

So keep in mind the masks only apply within a layer by default. They don't get sent up to the next layer, but get combined with the Source first, and then everything gets sent up to the next Track Layer (if any). This is sometimes different from how some other applications handle layered compositing.

There are exceptions for this in more advanced ShotANVIL editing modes, which we will discuss in detail in later tutorials. 

Just keep in mind for now that masks are local to a specific layer. 

So let's change the Viewer display mode back to Result. 

You can see we've got the mask blend mode here. We can invert it, we can make it outline only, we can change the feather. 

TITLE: TRACKING

Now let’s take a look at tracking, which at its core, works the same as our previous tracking products.

Select Track Layer 1, and go to the track controls panel here.

The purple highlight area shows the area which is used for the motion tracking. This preview is quite useful when we have multiple masks combined. The purple highlight then correctly displays the correct shape for the combined masks.   This will be shown in more detail in the advanced masking tutorial.

So let's just go ahead and jump forward to the finished track. 

The points of the vector mask shape can also be keyframed over time, but in this case lets just scale the whole shape and adjust the feather. Now we have the shape we want for the final mask, and it will continue to follow the completed track.

Tweak the feather a bit, and then we can check the result across the entire track, and it looks like it’s covering and following the helmet quite well.

Maybe adjust that mask a bit tighter…

To go further we can add additional elements like paint strokes directly into the same track layer, and they follow along with the specific motion track we've already completed.

This is true for any of the brushes included, just as in PaintX. Add more strokes, and they still follow the same track in the Track Layer.

Moving on, let's say that we want to do an additional, completely separate track on a different part of the footage, like the breathing tube. 

Deselect the existing Track Layer 1, and click the Add New Layer button, then add a paint stroke.

With Track Layer 2 selected, double check that Motion Tracking > Pre-Tracking Options > Tracking Model is set to “Perspective”, and that Motion tracking > Post Tracking Options > Apply Track As is set to “perspective”, and then start the track.

This now tracks based on the area of the painted strokes, completely isolated from the track applied to Track Layer 1. 

We could go ahead and add as many layers as we need, each with different, isolated tracks, just  keeping in mind that each Layer only has one track.

TITLE: REVEAL SOURCE

Another important concept in Shot Anvil is the very powerful Reveal Source Brush.

To see what it does, add another Track Layer, then select the Reveal Source brush.

Using this brush will “paint back in” the pixels from  our original source clip along our stroke, based on the shape and feather of the brush. 

One way to think of this, is as though it is erasing through all of the layers below it, to reveal the  unaffected Source clip.

As we paint across the frame like this, it is erasing both the color correct and the brush stroke from the other Track Layers to reveal the original source clip.

This new Layer containing the Reveal Source Brush, can obviously then be tracked as well, and the track will remain unique compared to the other Track Layers.

So this is a basic overview  of the concepts involved in how you could layer up multiple shape masks and brush strokes and effects to modify the built in ShotAnvil tutorial.  Future tutorials will dive more deeply into the many mask options, tracking techniques, and some of the more unique and powerful effect filters.

TITLE: ORDER OF OPERATIONS

The one last topic to cover here is a quick clarification of the order of operations for the masks and elements within a Track Layer.

Simply put, the components are processed in order from bottom to top. In other words, each component affects the ones above it. The topmost layer is the final effect applied.

If we add a blur filter above a color correction filter in the Track Layer, we can see that the color effect is applied first, and then the blur.

You can reverse the order by dragging the components up and down within the list.

So just remember that within a Layer, elements are applied from bottom to top - the topmost element is the last one applied. 

In respect to tracking, each Track Layer contains a single motion track, which is applied to all elements within that Track Layer, and you can add as many unique Track Layers as you want to your ShotANVIL creation. 

In other tutorials, we'll go into more detail on how you can stack components, use masks, and then build your own effects. 

Thank you.