We will add a new layer on the timeline that you created on the previous exercises to composite an element on a background.

1. Continue with your timeline from the previous exercise.
2. Work in the Record Timeline view.
3. Display the Player if not already, Press ESC.
4. Navigate to the first shot of the timeline.
5. Press the Layer+ button to add a new layer to the timeline.
6. Make sure Ripple and Trim are disabled.
7. Make sure Snap Closest option is selected.
8. Select the first shot on the timeline.
9. Hold C and drag the “1_Entrance_Front” shot straight up to the top layer to copy it.

This way the bottom layer will already have the correct duration when we will add the backplate to it.

We want to composite the green screen shot on top of a different backplate.

1. Select the “1_Entrance_Front” clip on the BOTTOM LAYER of the Record timeline.
2. Press Shitf+ESC to access the Source/Record view.
3. Activate the view tab on the Source folder “Compositing” to see its content.
4. Select the “Entrance_Backplate” clip in the Source Area.
Note that this is a still image.
5. Press the Replace button (between the two players) to replace the clip in the timeline with the one in the Source Area.
6. The 1-frame background is stretched to fill the duration of the foreground and a soft Resize is automatically applied to fit the timeline resolution.
7. Press ESC to go back to the Record player.
8. Move the focus point up and down to see the clips on the two separate layers.
Hotkeys are Page UP and Page Down.

We will use the Axis soft effect, which is actually a DVE/compositor/keyer/color corrector bundled into one. This is your main compositing tool in the timeline.

1. Select Preview FX in the player settings, default is realtime.
2. Select the top clip “1_Entrance_Front” on the top layer.
3. Enable the Axis soft effect (first Soft FX on the list).
4. Disable Autokey animation (A) and press the Editor button (E) to access the Axis menu.
5. Also make sure the Preview mode is set to PreviewFX.
6. Click the Keyer button to access the Keyer sub-module.
7. In the Keyer, choose the Master Keyer.
8. Make sure Autokey is deactivated.

When you are using a project with proxies, make sure you work in "Full Res" view when you perform a key. Note: the option Full Res or Proxies is only available in menus when Proxies are setup in the project. See "Project & User" overview for more information.

On the matte we have different shades of grey that indicate what is opaque and what is transparent. A perfect key would be completely black in the transparent areas and completely white in the opaque areas.
The edges in-between would show very little aliasing.

1. Start by sampling the key color:
Click on the left color pot of the Master Keyer (grey box).
A color picker cursor appears.
2. On the green screen, drag from a dark shade of green to a very light shade of green to select a range of color to key out.
This automatically generates a key.
Notice that Auto CC is an automatic color suppression tool that removes the color Spill. Auto CC is enabled by default.
3. From the view menu, choose Matte, or press F3 on the keyboard.
4. Drag the keyer Mix slider left and right, and find a setting where you get the best initial key.
5. If you hold ALT while moving across the image, it will display different matte sliders.
On this particular key, there are not many significant ranges available, so we will use other tools instead.
But you can try dragging the Range E slider slightly to the right to increase the black value of the background if you want to try the tool.

Some general information on the Matte sliders:
The different matte ranges will affect the values inside the sampled area of the matte. The sliders on top are those that will influence the selection under your cursor the most. Some ranges are complementary and will not appear together. The best is to experiment with the different sliders on various shots.

The Result view hotkey is F4, Front view is "F1", Back is "F2" and Matte, "F3".

We will now use the Master Keyer Patches to clean the matte.

1. By default Sampling is set to Matte.
From the Sampling menu choose Patch 1.
2. Drag the cursor on the little spots of light grey that you want to force to pure white.
Note that Patch1 will be set to White because of your initial selection of light grey pixels.
3. Set the sampling to Patch 2.
4. Hold CTRL and drag a rectangular selection on dark grey areas in the image to force them to black.
Patch2 should be set to Black; if not, select Black for it.
When you sample the patch multiple times, these values are added in the patch.
You can add a third patch to improve the chains on the left side.
5. Set the sampling to Patch 3.
6. Hold CTRL and draw a rectangle that includes the chains.
The patch is set to Analysis because both black and white were included into the patch range.
This grey patch affects the edges of your selection.
7. Increase the range of Patch 3 while monitoring the matte and the result.
8. Stay in Result view to preview the final key result.

You can toggle a patch ON/OFF by clicking on the Patch button. To reset a patch, select the Patch and press Reset

The result is much better than what we had before, except that there is still some grey fringing around the gladiator and the walls.

9. Enable the Shrink tool in the Matte Tools.
10. Increase the Width value to expand the transparent areas into the opaque areas.
Be careful not to lose any of the fine details, a value of 0.6 should be sufficient.

Although the key is done, there is still an issue with the color of the walls in the foreground; they do not match the color of the background. To match the foreground color with the background, you can use the Colour Warper that is embedded within the Keyer.

1. Click the CCF button inside the Keyer to color correct the Front.
2. Switch CC to CW (Colour Warper).

To resize the CW vector scope, hold "SHIFT" and drag the scope. To move it, hold "ALT". To reset it to default, click on the Scope "Home" button.

3. Go to the last frame; this is the frame at which the gladiator is actually walking into the light.
4. Click the Plot button to define a sample color from the source.
5. CTRL-Drag an area of bluish-grey walls in the foreground.
A red circle appears in the vectorscope and indicates where the sampled values are.
6. Choose the Back view in the view list, shortcut is F2.
7. Click the Ref button to define a destination color in the background clip.
8. CTRL-Drag a colored brick area in the background that has similar levels of colors than your foreground selection.
A yellow circle appears in the vectorscope and indicates where the reference values are.
9. Choose the Result view in the list, shortcut is F4.
10. You can disable the Source and Destination buttons to unclutter the vectorscope.
These buttons are located under the Histogram.
11. Click and drag the midtones trackball towards your reference (orange).
You can see that the plotted circle in the vectorscope moves accordingly.
Aim to line up the plot and ref circles in the vectorscope.
Depending on your samples, you may find that the result is somewhere between the two circles.
12. To increase the color separation, boost the saturation somewhat by dragging the Saturation slider up.
13. Add a bit of contrast by lowering the Black slider slightly.
Now you can see that the foreground and the background are matching much better, both in terms of contrast and color.
14. Click RETURN to go back to the keyer, then RETURN to the Axis and EXIT to the EditDesk.

If the composite doesn’t look right on the timeline, make sure "Preview FX" is selected on the Player settings. You can also process the segment now to see the final result.

This composite looks good now, except that the back plate needs to be repositioned. When you select the back plate shot on the timeline, we can see that a Resize soft effect has been applied by default.
This is because we are adding a 3K back plate into an HD timeline. To reposition the back plate, we will use an Axis soft FX instead.

1. Select the “Entrance_Backplate” clip.
2. Enable the Axis soft effect.
The Resize SoftFX is automatically muted.
3. Make sure Autokey (A) is deactivated.
4. Click on the (E) button to enter the Axis Editor.
5. Set the view mode to Context.
This makes all layers visible inside the Axis menu.
6. Lower the Prop Scale value (around 75%).
7. Drag the Position Y slider down.
Reposition the background so you can see some blue sky and you hide the walkway at the bottom.

When you are working with very high-resolution images, you can generate proxies in the current project for a faster interactivity. For more information see the "Project & User" overview module.

We are almost done with this composite, but there is still one thing that gives away the fact that this IS composited: the back plate is sharper than the foreground plate. That is because the back plate comes from a still camera whereas the foreground plate comes from an HD camera. We will blur the back plate to simulate depth of field.

1. Still in the Axis Menu, look at the image controls on the right side for the Blur controls.
2. Set a value of 5 for the X and Y values to blur the image.
3. Set the blur type to Gaussian instead of Box, which is a much smoother blur.
4. Exit the Axis.

To link the X and Y parameters while dragging: "ALT+SHIFT-Drag".

To process the effects and play back the shot:

5. Select the topmost clip and click on the Process button.
6. Press CTRL+ESC to display the Full Screen Player.
7. Scrub the result or press ALT+L to replay.
8. Press ESC to go back to the Timeline.

As usual, don’t forget to save your work at every important step!

If you want to know more about the interface and the functionalities covered in this exercise, watch the following interface overview:


To continue with the exercises, click on the following link: