

Makes the white areas in the matte whiter. Use one or more of the following sliders to refine the mask: Currently, the background is in good shape, but the foreground could use some work.Ĭlick the disclosure triangle next to Screen Matte to reveal several controls that you can use to fix matte problems. However, the background should be solid black, and the foreground should be solid white. Avoid using a high value or halos will occur.įor a believable key, it’s best to have some gray pixels around the edge of the subject (so hairs and other semitransparent elements can blend into the background). Change the Screen Pre-blur to a value of 1.0 to slightly soften the edges of the generated matte.Some users alternately use the Clip Black slider discussed in the next section for similar results. For this first shot, a value of 110.0 works well. Increase the Screen Gain parameter until the background is a clean black plate.After Effects changes the composition size and automatically adjusts the clips to display properly. From the Preset list choose HDV/HDTV 720 29.97 to switch to a square Pixel Aspect Ratio. So, you’ll need to modify the composition’s settings.Ĭhoose Composition > Composition Settings. This composition uses non-square pixels, which will not work well in Flash. In the Project panel, double-click the composition 01_Keying_Start to load it.This project file contains all the elements you will use for this chapter. Open the file Chapter_04.aep from the Chapter_04 Project Files folder. Copy the Chapter_04 Project Files folder from the DVD to a local hard drive.Let’s start with some basic material that needs to be keyed. The good news is that there are only a few main controls and the rest are just used for fine-tuning. The Keylight plug-in can be a bit intimidating because it has nearly 60 parameters. It is also quite adept at properly keying reflections, semitransparent areas, and hair. Keylight is relatively easy to use (once you understand its options). So if you select green, it will remove the backdrop and greatly reduce any green reflections on the foreground. Second, it removes that color spill from other pixels. First, it erases all the pixels that match the color. When you apply Keylight to a footage layer, you choose a color to key out. Keylight has won the Academy Award for Technical Excellence and is a one-stop-shop for keying, despill, and color correction. This technology has been used on numerous feature films including Harry Potter, Mission Impossible, and Sweeney Todd. The technology used in Keylight uses a core algorithm written by the Computer Film Company. Included with After Effects is a powerful chroma key plug-in called Keylight. Let’s explore the process with three sample compositions. Second, you can easily access technology for converting video layers into Flash Video files with embedded alpha channels. There are two reasons for this: First, After Effects offers advanced tools for masking, keying, and compositing. The best way to create transparent video for use in Flash projects is with Adobe After Effects.
