AFTER EFFECT PARTICLE PLAYGROUND SKIN
AFTER EFFECT PARTICLE PLAYGROUND SERIES

It is essential in computer graphics to create motion blur. What is a motion vector? It is basically the direction and magnitude of velocity of an object in motion. I needed to know about the motion of the surface, so the logical thought was to explore the use of motion vectors. I started considering the “bag of tricks” that VFX uses these days. I needed a way to quickly recreate complex motion for particle systems, approximate fluid advection(hopefully), repulse or attract existing particles, all while preserving the dimensional “feel” of the animation. To describe this as complex, is truly an understatement.

This motion would alter dynamically under gravity (the only simple vector force I actually could use) and the motion would radically change as each particle bounced off of that surface. Any water flung by the creature would fly at the velocity of the surface point, and cascade down. Unfortunately for the current project, the motion of each piece of the creature was unique, and varied often along the surface. It is simple and archaic, by many definitions, but was sufficient for the current purpose, as all the particles flowed a single direction. Fractal noise was applied as an “ephemeral” property to introduce turbulence to the particle position - it is an unusual particle package which requires most particle properties be defined by textures, or global vector directions, and is occasionally limited to what texture map can be used for which property. This motion matte was used in Adobe After Effects with their primitive particle system Pixel Playground, to emit ghostly plasma blown by wind. Using this method, I was able to isolate the largest movements and their intensity. In 2004, for the special venue ride Haunted Lighthouse, for Seaworld parks, I used a frame differencing method to extract all the moving pixels in a given frame to emit particles from the flailing arms of Christopher Lloyd.

Nevertheless forging ahead, I animated some tentacles as individual parts, handed them to a compositor, and let them do their magic combining all the pieces for the final motion, while I mused about particles.

AFTER EFFECT PARTICLE PLAYGROUND SERIES

After all, this worked for me on the television series FRINGE, for a tentacled creature swimming in a tank, so I was reasonably assured that this would work. After the animation I would likely calculate a fluid field to advect the particles through, to give it some sense of fluid motion. If I did have it, it would take time to rig and animate, and match correctly enough to create particles.

AFTER EFFECT PARTICLE PLAYGROUND SKIN

I am fairly adept with 3D particles, but a particle system must have an emitter, which in this case was the skin of my character - usually 3D animated to match the footage. Since I was not planning on flailing around in the pool, and rotoscoping tons of water I needed particle systems to do this. Time was as usual, short, and running out. The particular scene In front of me required that a character from existing footage be combined with tentacles of my own making, repositioned to come out of water at the edge of screen, combined with a sky matte painting, and fling water off of its body at every flick or tiny movement.

After effect particle playground