Primatte Keyer: Using the Light Wrap Feature
A primatte keyer can be used for green screen effects. It works by extracting any color key from the background. Some of the benefits include the ability to deal with lighting issues such as shadows, edge contamination and compression artifacts. The light wrap feature will produce an illusion and take the light from the background, and then reflect it in the foreground. This is perfect to get light to reflect off the subject of the photo or video clip.
Step 1: Feathered Edge
It is necessary to take the rendered footage and then soften and blur the edges. The result will create a new alpha key that will then reveal a small amount of the background. This feathering creates the illusion that the background image is wrapping around the new element.
Step 2: Precomp
Set up the new footage in the precomp and name it something appropriate. It is only necessary to do this once within the project. This is fast and it is not necessary to wrap the light for each frame or clip that uses this tool. Apply blur to the new footage. The amount of blur will depend on how much light wrapping is desired. To get that feathered edge, drag an additional copy of the foreground into the light edged one, and place it underneath the blurred copy. The mode for this new copy should be set to Alpha inverted. This will create the feathered edge needed for the effect.
Step 3: Composite
Create a new composite that will contain a copy of the feathered object, a foreground copy and 2 copies of the background. To create the composite, put the foreground over a copy of the background. On top of this normal composite, add the light edge precomp which should be the topmost layer. The 2nd copy of the background should be set as in the alpha matte mode. This softens the edges of the foreground.
Step 4: Blending
It will be necessary to blend the edges of the foreground to the background so the wrapping interacts. The type and degree of blending will depend on the desired effect. If the new background should be illuminated, then brightening the edges may work best. Overlay and hard light can also be used to darken the correct edges in the background and foreground.
Step 5: Light Wrap
The light wrap function in primatte keyer is sold separately from the main software. It does not need to use as many composite layers to create. The results of the light wrap will differ as depending on the options used. The main issues that users have are that the options for the edges and blurring can be limited, and many professionals choose to do their own integrations. However, light wrap makes this very easy for those just beginning to use this type of effect.
Step 6: Ease of Use
This software makes this type of compositing easy and fast. It can work right on the video clip timelines and can greatly enhance lower forms of video formats and deliver high quality products. It is possible to place any type of element, product or person in the foreground. All of the inserted elements will blend into the background and appear as if the foreground and background belong together.