After Effects Color Key maskingIf you're interested in incorporating special effects in your films, chances are you're going to work with green screen, stock video, and After Effects to create your composites. In a recent tutorial, Andrew Trice shows us how to use all three in order to composite using keying, as well as utilizing techniques, like motion tracking, linear color keying, and tritone color correction in After Effects. Continue on to find out how Trice got away with setting off an explosion a block away from the Adobe offices in San Francisco.

The first demonstration Trice gives in the video is how to overlay footage shot in front of a green screen onto background video -- pretty straightforward. The second demo, however, shows us how to take a piece of stock video -- in the case, an explosion -- and overlay, track, blend, and mask it over a moving scene.

If you're just getting started with visual effects, learning how to key is probably high on your to-do list -- but the work doesn't end there. Pulling off a good effect means hiding the seams made when combining what is originally in your shot and what you put into it. Trice addresses this issue by showing you how to use several techniques.

First, he demonstrates how to use the motion tracking tool in After Effects in order to match the movement of the effect with the original shot. Next, he uses the linear color keying tool to get rid of the white background of the explosion, then adjusts the colors and softness of the edges to hide the seam. He finishes by applying a tritone color correction, as well as a mask to give the illusion that the explosion only follows the path the buildings provide.

What do you think about Andrew Trice's tutorial? Do you have any tips on keying, blending, masking in After Effects? Let us know in the comments.

[via Andrew Trice]