Using Virtual Clips

Virtual clips can be a difficult concept to grasp?and knowing when to use them can be even more confusing.

A virtual clip is a segment of your project stored away on the timeline for future use. It can consist of all the usual editing tools and media you use elsewhere in your project: clips, audio, images, effects, transitions, and mattes.

You'll create a virtual clip for one of a variety of reasons:

  • To use the same segment several times

  • To apply different settings to the same clip in various locations in your project

  • To create two or more transitions between the same two clips.

The following task provides an example of the latter.

Task: Create Multiple Transitions Between the Same Two Clips

To create two or more transitions between the same two clips, follow these steps:

  1. Place two clips consecutively on Video 1. If you need to make adjustments to create tail and head room to make a smooth transition, do that.

  2. Apply an obvious transition to them, such as Cube Spin. It's in the Transitions 3D Motion file folder. As a reminder, all you need to do is drag Cube Spin to the junction of the two clips and drop it there. No need in this case to adjust any settings.

  3. Preview the transition. One scene should appear to push the other away from left to right.

    If you were to apply another transition to those clips, it would replace Cube Spin, not work in conjunction with it. To make two transitions work together, you need to create two virtual clips.

  4. Click the Block Select tool. I've highlighted it in Figure 16.14. Use it to draw a box around the clip on the left, making sure the right side of the Block Select border falls right between the two clips. Snap to Edges should make that easy. I've highlighted this in Figure 16.15.

    Figure 16.14. Use the Block Select tool to make virtual clips.


    Figure 16.15. Carefully set the border of your virtual clip right on the junction between the two clips.


  5. Release the mouse button and note that the cursor turns into a double arrow. Click and drag that double arrow and its highlighted clip to another track. Premiere will rename it "Virtual Clip." Note the times for the in- and out-points of the original clip.

  6. Do the same thing for the second clip, making sure you set the left side of the Block Select border right on the junction between the two clips. Drag it to the right of the other virtual clip.

  7. If you lined up the two virtual clips side by side, as they are in Figure 16.16, you can use the spacebar to play the timeline. The Cube Spin transition will play.

    Figure 16.16. Use the spacebar to play the two virtual clips?transition and all.



    This ability to view a transition without previewing or rendering is a feature of virtual clips. The virtual clip plays as if it has been rendered or is in a preview mode. If you use the spacebar to play the original two clips with the Cube Spin transition in place, you will not see the transition.


    One of the confusing aspects of virtual clips is that they always remain connected to their original clips. If you change something about those original clips?add an effect, trim them, alter the transition?that will show up in the virtual clip(s). If you place a virtual clip in several locations within your project, the changes will show up in all instances.

    To see that in action, go back to the original two clips and lengthen the transition from the default 30 frames (one second) to something longer. Do that by right/Option-clicking the transition, selecting Duration, and typing in a new time. Now go to the virtual clips and play them, and the transition time will equal what you just typed in.

  8. Drag the two virtual clips to Video 1. I want you to add another transition to them, and Premiere allows transitions only on Video 1.

  9. Drag Page Peel (from the Page Peel Transitions folder) to the junction between the two virtual clips and then preview your double transition. It should look something like Figure 16.17.

    Figure 16.17. Using virtual clips makes it possible to apply two transitions to the same two clips.



    Using the spacebar will not play a new transition placed between two virtual clips. You need to make another virtual clip to do that. That's a so-called "nested virtual clip" (a virtual clip within a virtual clip).

Using Virtual Clips to Enhance Two Special Effects

The Echo video effect disables all effects applied above it (before it) in the Effect Controls palette. Frequently you want to apply some other effects before using Echo. An excellent workaround is to use a virtual clip.

First, apply the effects that you want to precede Echo, create a virtual clip, and then apply Echo?and any other effects after it?to that virtual clip.

Task: Use Virtual Clips with the Echo Video Effect

Try this:

  1. Clear the timeline and place a clip with some action in it on Video 1.

  2. Apply just about any video effect to that clip. I chose Invert. It reverses color or luminance information, creating a color negative (inverse) effect. In Figure 16.18 I selected HLS (Hue, Lightness, and Saturation). I like setting the Blend With value percentage to something greater than 60% for a nice color mix.

    Figure 16.18. The Invert effect with Hue, Lightness, and Saturation applied.


  3. Drag Echo to the Effect Controls palette. It will immediately switch off whatever video effect you already applied. Echo causes Premiere to ignore all effects applied before it.

  4. A virtual clip will remedy that. Before creating one, remove Echo by selecting its name in the Effect Controls palette and clicking the garbage can icon at the bottom right of the palette.

  5. Click the Block Select tool, drag it around the clip with an effect applied to it, and drag the double-headed arrow to another location. In my case, as you can see in Figure 16.19, I dragged it just a bit farther to the right on Video 1.

    Figure 16.19. Drag the virtual clip to another location on the timeline.


  6. Apply Echo to the virtual clip. To make sure that Echo is actually working, set Number of Echoes to about 4 and reduce Starting Intensity to about 0.25. It should have a look and feel that approximates what you see in Figure 16.20.

    Figure 16.20. Using a virtual clip lets you apply Echo to a clip with another effect already on it.



    As a reminder, to avoid creating an overly bright Echo effect, the starting intensity should be about equal to one divided by the number of echoes (1 / 4 = 0.25).

  7. Preview your work. Echo no longer trumps effects applied before it. And now you can add even more effects.

Task: Use Virtual Clips with the Texturize Video Effect

The Texturize video effect will not work with motion settings. But there are many times when you might want to add motion to a texturized effect. Once again, a virtual clip can fix that. Here's how:

  1. Place a graphic on Video 1. Apply motion settings to the graphic. As I've done in Figure 16.21, have it move across the screen and spin around a couple times.

    Figure 16.21. Apply motion settings to a graphic to prepare to demonstrate another use for a virtual clip.


  2. Place a video clip on Video 2. Because the clip is opaque, you will not see the graphic on Video 1.

  3. Extend the graphic clip on Video 1 to match the length of the clip on Video 2.

  4. Apply Texturize to the clip on Video 2. As I've demonstrated in Figure 16.22, select V1A as the location of the clip you're applying texture to and increase the Texture Contrast setting to enhance the effect.

    Figure 16.22. Give Texturize higher contrast to further emphasize a graphic.



    V1A stands for the Video 1A track. However, you are not using A/B editing, so Premiere recognizes that V1A is the same as the Video 1 track.

  5. Preview this effect. The graphic remains stationary. Texturize turns off the motion settings in the clip it applies texture to.

  6. Fix that by creating a virtual clip. Slide the clip on Video 2 out of the way. You need to do this because the Block Select tool surrounds all clips on all tracks above and below the selected clip. Then, as I've illustrated in Figure 16.23, drag the Block Select tool around the graphic on Video 1 (it should still have motion settings applied to it) and drag this virtual clip to some open space on the timeline.

    Figure 16.23. Create a virtual clip to preserve motion settings.


  7. Switch back to the Selection tool (use the V hotkey or click the Arrow icon in the toolbox) and then drag that virtual clip back to Video 1. Line up the clip on Video 2 above the virtual clip. It should still have Texturize applied to it.

  8. Preview your effect. Now the logo should follow the spinning motion path and have a look and feel similar to that in Figure 16.24.

    Figure 16.24. Use a virtual clip to create a texturized graphic with motion settings.


Fine-tuning Keys with a Virtual Clip

Keying can be hit or miss. Frequently you'll be hard pressed to remove pixels near the edges of the subject you want to key over a background. Other times "hotspots"?unevenly lit areas of your green/blue screen?will not key out. Creating a virtual clip to apply a key twice can help. It's not a guarantee, but it frequently makes the difference between unusable and acceptable.

Task: Fine-tune Keys with a Virtual Clip

To fine-tune keys with a virtual clip, follow these steps:

  1. Use a clip from the assignment number one back in Hour 14, "Compositing Part 1: Layering Images and Clips." That called for you to tape a subject in front of a solid?and differently colored?backdrop. Drag that clip to Video 2.

  2. Drag a background to Video 1.


    Instead of a video clip background, consider using a color matte. This gives you a more accurate representation of how well your key is working. As a reminder, to make a color matte, right/Option-click a white area in the Project window, select New, Color Matte, select a color, give your matte a descriptive name, and click OK. The matte will appear in your Project window.

  3. Open the Transparency Settings dialog box for the clip on Video 2 and apply a color-based key: Chroma, RGB Difference, Blue/Green Screen, or Non-Red.

  4. Adjust the slider(s) as well as you can without impacting the subject. My example in Figure 16.25 has a hotspot that does not key out without creating a transparency in the subject. Click OK.

    Figure 16.25. A first-time application of an RGB key shows a hotspot on the green screen.



    You might try different keys. RGB Difference might work better than Green Screen, depending on how closely your green screen matches true chroma green.

  5. Drag the background clip away from under the keyed clip on Video 2. As I've shown in Figure 16.26, don't take it too far. You'll use it again in a moment.

    Figure 16.26. Slide the background color matte a little to one side so you can place the virtual clip over it to apply another key.


  6. Use the Block Select tool to drag a border around the keyed clip and drag that newly created virtual clip right above the background clip. Figure 16.26 shows how your timeline should look now.

  7. Apply transparency to the virtual clip. Note that when you open the Effect Controls palette, the Transparency box is not checked. This is a virtual clip, so you can apply transparency to it as if you hadn't done it in the original clip.

  8. Use the same key you used in the original clip and attempt to key out the remaining unkeyed region. In Figure 16.27, I managed to key out most of the hotspot left unkeyed in the original clip.

    Figure 16.27. Applying the RGB key a second time to a virtual clip cleans up most of poorly keyed portion of the original key.



If you carefully adjusted Similarity or other values in the original clip so there was almost no unkeyed area left, you might not be able to use the Eyedropper tool in the virtual clip to select a color to key out. Therefore, go easy on the first attempt.

Because you're working on a virtual clip, you may extend the background under both clips and readjust the keying in the original clip to give your Eyedropper tool a larger area to find a color to key out. Those changes will show up in the virtual clip. Once you've selected a color in the virtual clip to key out, you can go back to the original clip and tighten up the key there.

    Part II: Enhancing Your Video