Particle animation: isn’t that something to do with physics?

If you’re wondering how particle animations work, going back to their beginnings is a pretty good start. In 1982 cinema viewers were treated to one of the first on-screen particle simulations in Star Trek: Wrath of Khan. Kirk, Spock and Dr McCoy watch as one Dr Carol Marcus explains the genesis project in a pre-recorded presentation. The trio see the Genesis Demo as a simulation on a computer. In the magazine American Cinematographer, Alvy Ray Smith described the 67 second sequence as created from several different computer-generated components, including the particle animation of fire spreading across a planet created from code written by Bill Reeves. Beginning with a projectile (the genesis torpedo) speeding toward and hitting the planet surface, the sequence continues with a fire, initially at the point of explosion before spreading out. Immediately, other CG elements populate the imagery – fractal mountains, lakes, oceans of water, and finally an atmosphere looking like that of Earth complete the evolution of the new planet from its fiery origins.

The Genesis Demo set the foundation for the thirty-five years between now and then. Bill Reeves’ 1983 article ‘Particle Systems,’ is a great place for starting to get to grips with particle animation. Reeves writes in a very informative way, and you don’t need to be able to make sense of the equations to gain some insight into his software. As he explains, when creating a shape using particles, its dimensions are given by the volume of a particle cloud, meaning the specific boundaries of it’s shape are not fully defined (he uses the word determined). Because a particle cloud is continuously generated, objects created in this way are dynamic and fluid, as opposed to static. This makes particle animation ideal for ‘fuzzy systems’: smoke, fire, clouds, moving water, sparks, fog, snow, and dust. For particles animating the spread of fire across a planet, their motions and transformations are tied to the solution of equations. These form the basis of algorithms that mathematically model the physics of natural phenomena, water crashing down from a height, the swirl of snow or smoke. Reeves included a randomised (stochastic) input that controlled the emission of the particles, and the software also granted a model builder some control over how the physics of the system would play out. As Reeves explains it: ‘To control the shape, appearance, and dynamics of the particles within a particle system, the model designer has access to a set of parameters. Stochastic processes that randomly select each particle’s appearance and movement are constrained by these parameters.’ The Genesis Demo wasn’t the first time that particle animation was used for things like smoke and galaxies, but Reeves introduced randomness and a degree of creative control to the process.

Still: particle animation of fire used in the Genesis Demo

In the thirty five years since Star Trek: Wrath of Khan, particle animation software has developed, with packages like Houdini, Maya’s Particles and Blender widely used in visual effects for cinema, animation and games. These increasingly sophisticated systems still rely on solving equations to simulate an object such as water in Moana or sand in Mad Max: Fury Road’s toxic storm. Simulations are often widely applauded for their degrees of accuracy in the movements and transformations of particles. At the same time, developers constantly aim to enhance the control available to visual effects artists. While particle animation algorithms are designed around physics, visual effects are not just about simulating reality. Often, something dramatic is what’s needed, and that is where artistic control comes in. The challenge for software developers is too make their packages open to artistic control. The challenge for people interested in cultural politics is to understand the ways and the extent to which simulations are not altogether real.

William T. Reeves (1983) ‘Particle Systems: Technique for Modelling a Class of Fuzzy Objects.’ Computer Graphics 17 (3) 359-376.

A VR first timer

Last week I had my first ‘proper’ experience of immersive VR. A year ago or so I’d tried out the VR experience at the National Theatre’s production of I also had a go at Google Cardboard. But neither quite prepared me for the latest in VR (on a PS4). My friend brought along his system plus the games. First up was Ocean Descent. No interactions involved, but you were dropped to the bottom of the ocean. I couldn’t get over how easy it was to let myself ‘be’ in the diving cradle while standing inside a room on a university campus. Almost immediately I wanted to reach out and touch the animated fish in the VR underwater environment. (Spoilers) Once the shark attacked it was so strange to feel a sense of physical vulnerability after the Great White had ripped off the protection bars at the front of the cage, and my virtual belly was there for the eating. Next I progressed to The London Heist, and interaction. The quality of the sound design was what struck me most in this game (along with my inability to keep hold of the gun at the most crucial moment – I was stabbed to death, unable to shot the bad guy because I’d dropped the gun (twice!)). I was really impressed with the scaling of the game sound. If I moved a mobile phone away from my ear, the sound immediately adjusted to where I’d positioned my hand. A simple example of an impressive audio system, which makes sound an important feature, not just to the fiction but the immersive positioning of a player in VR space. The audio gets really complex during the chase, with gunfire, roaring engines and the screeching tyres of vehicles, wind noise, and dialogue.

Having dived to the bottom of the ocean, raced in a car chased by motorbikes and armoured vans, (and tried out as Batman, but let’s not mention the glitch) I then took on the role of a rebel and flew an X-Wing in Star Wars™ Battlefront™ Rogue One™: X-wing VR Mission. Whoop whoop. It was fun flying around asteroids and fighting the great fight, even if my swooping movements meant things were beginning to get a little queasy. My last game was Until Dawn: Rush of Blood. This time my vehicular experience was a roller coaster Ghost train, which for queasy me meant I didn’t get too far through the levels of the ride. Still, I got a real sense of why so many people are saying this is a great game to play on VR (though players of non-VR versions of the game seem less impressed). The game’s sound is great again – really sets you on edge.

So, overall, what did I think? I’m not sure I thought very much as a first timer, just played the games for the experience. It was fascinating to find myself so willing to reach out, physically act out throwing virtual objects, lean forward and back, turn around, tilt, twist, crouch, or yelp as necessary. I was also struck by my embodied reactions having being made nervous, afraid, even scared, as and when they were provoked by a game. The London Heist didn’t give me cause to have this response. Sure it was exhilarating, but in the end you just kept shooting without much fear. But in Rush of Blood, things got more freaky with a growing sense of vulnerability to the on-coming ghosts and ghouls who get pretty much in your face and, via the audio, in your ears.

Anamolisa and stop-motion: weirdly close to human

Anamolisa and stop-motion: weirdly close to human

 Anamolisa’s directors (Charlie Kaufman and Duke Johnson), animators and producers (Starburns Industries) make great use of stop-motion. Far from being limited to the commercial successes of films such as LAIKA’s Paranorman or Aardman’s The Pirates! In An Adventure with Scientists!, the technique is widely used to craft strange worlds, such as those of Adam Elliot’s claymations, or Daisy Jacobs’ BAFTA winning life-size stop-motion short The Bigger Picture (2014). In Anamolisa the technique adds visual richness to the story of a man who struggles to hear, see, and engage with individuals in the crowded house of humanity.

Michael Stone, Anamolisa’s central character, is a middle-aged British man living in LA and visiting Cincinnati where he is to attend a conference as its keynote speaker. We see him arrive at the airport, get a taxi to the hotel, check in, go to his room and so on. These early sequences not only introduce us to Michael, a man with ‘dashed expectations,’ they also show how effectively the animators have used stop-motion to give substance to the world Michael finds so perplexing.

Written and directed by Charlie Kaufman under the pseudonym of Francis Fregoli, Anamolisa was first performed as a sound play at The Theatre of the New Ear in Los Angeles. The three actors spoke their dialogue sitting simply on stools in front of an orchestra, accompanied by a foley artist who created all the necessary sounds. The animated version closely follows the original script and is voiced by the same actors (David Thewlis as Michael, Jennifer Jason Lee as Lisa, and Tom Noonan as everyone else). By separating dialogue from action, and demonstrating the mechanics of sound production, the sound play evoked the dislocation felt by Michael.

A sense of dislocation is conjured too through the technique of stop-motion animation. In Michael’s world (he may have a condition known as Fregoli delusion), everybody looks and sounds alike, regardless of gender, age, race and ethnicity. Aside from those of Michael and Lisa, all the puppets have the same face and are voiced by a single actor.

Beyond this device, Anamolisa makes the most of stop-motion’s ability to show us a world with familiar physics and dimensions, though one always askew. Sets are built to the same dimensional order of the world we inhabit, but scaled to match the foot-high puppets. Another layer of familiarity lies in puppets that walk or run through recognizable spaces, airports, hotels, along corridors, or up or down stairs, in the same way we do. And familiarity is further enhanced by the puppet design. The silicon puppets look almost anatomically correct, which we know because we see Michael exiting his shower, and both he and Lisa are naked during the sex scene. Despite these layers of familiarity, there are disjunctive and confounding connections too. Stop-motion movement inevitably reveals its artifice and so is never quite human enough. The puppets have larger than scale heads, and through the technique of rapid prototyping 3D printing, their faces are visibly constructed parts of a whole.

 Rapid prototyping 3D printing was first developed at the LAIKA Studio for Coraline (2009), and later Paranorman (2012) and The Boxtrolls (2014). The technique involves first generating the cheek and mouth shapes necessary for lip-sync, and also expressive changes around the eyes and forehead, as digital models. These digital models are printed out as 3D resin shapes, and placed on each puppet’s face on a shot-by-shot basis to create mobile and expressive faces. Side-effects of 3D printing include visible seams between the different facial parts and flaws from the printing process: colour deviations between print runs and striation patterns from the horizontal layering of resin. In Anamolisa, retaining these flaws and showing the imperfect joins across the eyes and around the hair and jaw line reveal the mechanics behind the stop-motion technique, and keep the puppets only, though weirdly, close to human.

 Not surprisingly, given Anamolisa’s origin as a sound play, dialogue is important too. In a game with customer service platitudes (Michael has achieved national success as a customer service guru), there’s an over abundance of meaningless words when Michael consistently fails to engage with the taxi driver, hotel receptionist, bell hop, and room service. Even in more personal conversations with his wife and ex-girlfriend, he seems given to a bewilderment that finally collapses into impatience, distraction, or indecision. In a lovely sequence that blurs the boundaries between technique and story-world, Michael is shaken by a profoundly destablising moment in which a revelation of the mechanics of sound and stop-motion coincide. Looking at his face in the bathroom mirror, he glitches. The different moving parts of his face cease to co-ordinate and instead distort as the lip-sync fails, while his voice becomes warped and mechanical. Here, Michael is caught between puppet and character, a dilemma resonating with his experience of life.

In Anamolisa, stop-motion’s facility to shift its audience between the registers of strangeness and familiarity is well suited to the story told by Charlie Kaufman. Given the enthusiastic reviews the animation has received, it will be interesting to see whether makers of stop-motion shorts and features will have more opportunities to step-out of the niche of family entertainment, and take on the challenge the technique is so very suited to meet.

Entangling with The Pirates! In an Adventure with Scientists!

I’m beginning a piece on the Aardman animation The Pirates! In an Adventure with Scientists! or Pirates! Band of Misfits, as it is known in the US. The Pirates!, though primarily a hand-crafted stop-motion animation, uses a lot of CGI, with some 80% of shots involving a digital touch too. Where the figures are stop-motion puppets crafted from clay (or silicon or even foam), and the sets are physically built in the Aardman studio in Bristol, a lot of details were removed using digital tools (rigs used for the complex acrobatics of action scenes, joins between the 3D printed and hand-sculpted elements of the figures’ faces, as well as glitches from dead pixels in the cameras). The partying pirate crowd and rows of seated scientists were populated with digital extras, Blood Island was digitally enhanced and the roofs of London sometimes digitally finished. From this list it’s clear that in The Pirates! physical and digital elements are consistently intertwined and nothing is ever quite as it seems on the surface.

So far so good, but where to go with this? Well, the idea of entanglement is something I’ve been wanting to explore more for a while. My starting point is Tim Ingold who has a fascinating way of describing how objects are different to things. Where objects are already described, solidified into categories, things are more fluid, knots of constituent threads trailing beyond the surface boundaries of a thing and becoming caught up with other threads. Things are entangled, ‘a meshwork of interwoven lines of growth and movement,’ changeable configurations of knots and threads.

Ingold is talking about things generally, and grounds his more abstract thinking with examples of things in the world, such as kites or trees. Kites are one thing when constructed inside a room, and become another when taken outside to fly or not, as the case may be. As I read about ‘kites-in-the-air,’ I think I grasp the point about things but find it hard not to let it slip again when musing about the possibilities the idea offers for moving image studies. Even so, Ingold’s description of things being entangled, of things having interwoven lines of growth and movement remains attractive when looking at how physical and digital elements are entwined in The Pirates!

curvy-pirateSurprisingly Curvaceous PirateThese very preliminary thoughts throw up an issue when using entanglement to think about entities in moving images already made. In one sense they are in keeping with a description of objects as completed works, already given categories, and often thought backwards – traced back to the intentions of their makers. Take the Surprisingly Curvaceous Pirate, a cross dressed woman who seems to have either escaped everyone’s notice or whose obvious pretence simply goes unmentioned. Thought backwards, Surprisingly Curvaceous Pirate’s origins lie in the five novel series on whose stories The Pirates! is based, but taken to a different level in the animation with the curves of her body and patently fake beard all part of the joke. In contrast to thinking backwards, Ingold encourages a process of thinking forwards, of trying to anticipate what might emerge in what he calls a gathering together of the threads of life, and be attentive to all the goings on that come together as a thing is made.

How might this work for the Surprisingly Curvaceous Pirate, or anything else in The Pirates!? One of things that intrigues me about the animation is its playfulness around disguise. But instead of trying to settle on what something is or isn’t, I’m going to look beneath the surface, to the knotted strings that pull together. The Surprisingly Curvaceous Pirate’s face is never revealed, but all the knots are there. In the same way, even though the boundaries of digital and physical elements of the image might appear settled, there are many knots to unpick.