The Advanced Art of Stop-Motion Animation: Visual Effects - Part 3
Computer software and tools allow for all kinds of live-action or CG effects to be composited into stop-motion to embellish shots or add any elements needed to tell the story. Effects such as smoke, water, fire, explosions, or gun-muzzle flashes can be downloaded or purchased as QuickTime files through various websites or service companies. These effects will typically be shot against a black background that is pre-keyed with an alpha channel. This way, if you simply drag them into a timeline in Premiere or After Effects, they can easily be laid on top of any other movie file with the background being automatically transparent. In many cases, they will then need to be re-positioned and modified to line up and match with your scene.
This effect was used for my two-character dialogue scene that is featured in Chapter 7: Character Animation and watchable on the accompanying CD. Searching through various movie files of fireballs, I found one that was suitable to use for the effect of the monster shooting fire out of her mouth. The movie file itself had the fireball shooting upward in the middle of the frame, so it would obviously need to be rotated and re-positioned to shoot diagonally off the right of the screen. This was all done in After Effects and lined up to match the monster’s mouth at the proper frame in the animation. Initially, the edge of the fireball was a flat line based on the bottom frame of the movie (Figure 9.51), so the shape was modified using a mask (Figure 9.52). The mask could change shape and essentially be animated in every frame to get the proper shape for the overall effect (Figure 9.53). Two copies of the same fireball movie were ultimately mapped over each other, rotated, and blended to give all edges of the fireball some variety and texture. (Compositing and screen grabs for the fireball effect in Figures 9.51 to 9.53 courtesy of Gautam Modkar.)
Online resources where you can find effects to composite into your own stop-motion films include:
www.stopmotionmagazine.com (under Free Stuff)
In addition to compositing in live-action or CG elements that are pre-photographed, it is possible to simply draw stylized effects right over your animation frames, such as lightning bolts, laser blasts, or anything that fits your scene. This can be done easily in newer versions of stop-motion software programs or externally in Photoshop. It can also be done using TVPaint, which is a software program used primarily for drawing 2D digital animation within the program itself. It can also be used for shooting stop-motion very effectively, and all of the drawing tools that come with it can be executed right on top of the stop-motion images. You can easily add hand-drawn effects, smear your stop-motion images, paint over them, blend the edges of seams on your puppet, and do a variety of other creative tricks.