Autodesk 62205-051408-9001 User Guide - Page 633

Setting Up the Discreet Keyer ❚❘❘ If you are keying an uneven blue or green screen, you can apply filters to correct the blue screen, and then apply the Keyer, or use another operator as a key-in source. In this case, the transparency of the front clip is based on the matte created by keying the second key-in source. For information on loading clips, see "Importing Footage" in Chapter 4, "Building Workspaces''. For information on working with uneven blue screens, see Keying Uneven Blue Screens. You can also key a clip without building a composite, for example, to generate a matte for use in another branch or another composite. To do so, choose File | Open, select the clip that you want to key, and choose Discreet Keyer in the Open Footage dialog that appears. You can also add a Keyer operator to a branch in the Schematic view. For information on using an external matte, see Chapter 9, "Working with Image Channels''. Applying a Keyer Operator You apply the Keyer operator to the front layer so the transparency allows you to see the back layer. The operator can be added directly after (downstream of) a Footage operator or after other operators. To apply a Keyer operator: 1. Select the front layer. See "Making Layers the Current Object" in Chapter 5, "Compositing''. 2. Choose Operators | Keying | Discreet Keyer. The active viewport displays the front image keyed over the background, based on the default Keyer settings. Setting Up the Viewports for Keying You can customize the viewports according to your personal preference. For example, if you want to preview the key on the entire clip, use two viewports, one for keying and one to play back the animation. Or, if you prefer to work on the matte, use several viewports, one to key, one to display the matte, one to view the composite, and one to play the animation. To set up the viewports to preview the animation: 1. Select the two-viewport layout . The composite appears in both viewports. 2. Click one viewport to make it active, and then click the Play Forward button . As the clip plays in the first viewport, you can preview the key over the duration of the clip. Use the second viewport to refine the key on a single frame. As you adjust the key in the still viewport, the animation updates in the dynamic viewport. To set up the viewports to display the matte and the key in context: 1. Select the two-viewport layout . The composite appears in both viewports. 2. Select a viewport, then double-click the Composite operator in the Workspace panel. The key appears in context in the selected viewport. 3. Select the other viewport, then double-click the Keyer operator in the Workspace panel. The output of the Keyer appears in the second viewport. 4. Click the second viewport, and choose Window | View Mode | Alpha. Now one viewport displays the matte, and the other displays the key in context. You can use the Keyer sampling tools in either viewport. Note: The active tool is tied to the active viewport. Therefore, if you switch tools in one viewport, then switch to another viewport, a different tool may be active. You must select the tool again in the second viewport if you want to sample with the same tool from both viewports. 617