# Character Essences Begins

After a few years of improv theatre, animation research and coding I think it’s time to begin my dream project. Character Essences will combine theatre techniques of character creation with traditional and procedural animation. Drawing on character archetypes from Commedia dell’arte and the physical theatre methods of Jacque le Coque and Rudolf Laban, the main focus is to find movement parameters (constants and variables) that define well established characters.

Once the parameters of movement have been identified, they can be manipulated to create a large variety of characters procedurally. The uses include video game automated character generation, extra characters in films and autonomous robot movements. One of the goals is also to simplify movement patterns without the need for large data sets like in machine learning. My belief is that by focusing on the intrinsics, rather than the extrinsics of character movement one can better identify the corresponding building blocks.

Characters can range from simple primitive models to animals and humans. Early experiments included Expressing Emotions Through Mathematical Functions (see description HERE) for primitive models. I found that combinations of fast, sinusoidal movements can create the illusion of joy in spheres and cubes, for example. These observations are linked more to psychology and to the Heider-Simmel experiment. If human emotion can be identified in such simple entities, surely adding a recognizable shape to the character (eg. biped, quadruped) will produce more relatable experiences with the observer. Let the adventure begin!

Keywords: Archetypes, procedural animation, psychology, biomechanics, equations, theatre, characters

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# World Problems: Ep.1 – Global Warming and the Magic Box Designs

“Scientists have recently determined that it takes approximately 400 repetitions to create a new synapse in the brain – unless it is done with play, in which case, it takes between 10 – 20 repetitions.” (Dr Karin Purvis)

### Motivation of World Problems Series

I’m starting Ana’s Research and Play with Episode 1 of the World Problems (WP) series. WP will have longer episodes (~15 mins) that combine ideation, design, prototyping and testing of sometimes crazy inventions. It is intended to experiment with possible solutions to help “save” the world. The approach is a playful one, rather than a worried and tense one. The reasoning is my belief that people achieve their best when fear of failure is out of the way.

The inventions that result from this series might or might not be viable. In this sense, WP presents a humble method to saving the world. My ambition is not to come up with precise inventions that will give accurate results (although they are very welcome). In my experience, having such pressures, under the constraint of limited time, leads to mediocre solutions and headaches. What I am trying to do is follow my curiosity and allowing myself to both innovate and fail (first attempt at learning).

In the best case scenario, the world will benefit from an invention. Worse case scenario, I will have brainstormed some ideas that fill people with such indignation at my nerve, that they’ll just go and make their own creations. Empathy also motivates me and it is necessary to prevent an attitude of carelessness and lack of responsibility. It is important, however, to use empathy as a driving energy rather than an energy draining one. We should all make a contribution to saving the world we live in, but it mustn’t destroy us in the process – unless it’s a sacrifice of love, but that’s a different story. Let’s begin!

### Episode 1 Summary

In this episode I come up with a few crazy designs to help save the world from global warming, by using random household items. It all starts with choosing the problem out of a list of possible world problems. I then have a warm up (of my mind, not the world) by finding different uses for household items via lateral thinking.

The Magic Box, which is often seen in clowning exercises comes into play. This leads to shotfire brainstorms from Experimental Ana, who gives up grammar for creativity. It all ends with a set of crazy invention designs (see below). One of them or a combination of up to three of them could be prototyped in the future.

### The Research

Episode 1 is linked more to brainstorming ideas, but research elements also find their way through. Please see the video description for the references used. Here are some research inspired elements from the video.

• Choosing the problem
• Motivation of play based approach
• Review of a few accidental discoveries
• Background on Lateral Thinking
• Ideation of designs
• Designing possible prototypes

### The Play

The structure of Episode 1 is linked to an improv game called Fix it MacGyver! In this game, a character called MacGyver is given a problem and three random items. He or she has to come up with a solution to fix the problem by utilizing the given items.

For example, let’s say someone’s house is on fire. MacGyver has a cat, a sandwich and a chainsaw. One solution is of course to use the cat as a scout to check if there are any survivors. The chainsaw can be used to cut through the fallen parts of the house, so that the trapped victims can be reached. Once they are out, a sandwich is provided for nutrition, while waiting for the firemen.

The idea of the game is not to “get it right”, since there are “no mistakes, just opportunities in improv” (Tina Fey). Letting your thoughts imagine the wildest solutions is very liberating because it cuts out inner criticism. What improvisers experience with this game is also linked to Julia Cameron’s theory, described in her book The Artist’s Way. She recommends evading the inner critic by free writing three pages of whatever comes to mind every morning.

My Experimental Ana from the video uses this technique of free and spontaneous thought. Censoring of ideas is kept to a minimum, giving priority to the joy of discovering where my own thoughts take me. In the paraphrased words of Keith Johnstone, one of the pillars of improv, “You must trust that your mind, God or the giant moose will tell you what to say.”

The elements of play in Episode 1 are the following:

• Defining the game guidelines (box of objects + find different uses for them)
• Magic box game linked to clowning exercise
• Lateral thinking solutions to a problem breaks patterns of thinking
• Experimental Ana uses free and spontaneous thought
• Experimental Ana uses jump and justify improv technique (say the word first and then justify its meaning)
• Creating designs with commitment

### Designs

After the research and play collaboration, seven designs emerged. These are not necessarily viable designs, but they open up a world of possibilities! Please have a look and tell me which of these designs you would like prototyped in the future!

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# Robin Animator V1.0

The Robin Animator V1.0 is a Maya plugin written in python for animation prototyping. It can be used to generate basic procedural animations of little bird characters. These animations can then be exported for your games, rendered in your films or can serve as reference for more complex animations.

Motivation

The question behind this project was to see whether we can create complex bird animations using simple movement components. This can be linked to emergence theory and subsumption architecture. The former talks about how a complex system is greater than the sum of its parts, while the latter shows how apparently intelligent looking behaviour can arise from a set of simple, separate component behaviours. In other words, complex character animation CAN be the result of simple movements working together!  In our case, the component behaviours link to the way each body part moves and tend to act independently from each other.

Robin geometric prototype model

I chose to focus on little bird characters, robins, to be more precise. The reason behind this is that I’m fascinated by how these little creatures move. Their speed seems to be in a different time frame from ours, due to their minute proportions.  After looking at robins in the real world for a while, I decided to approximate their movement with a geometric prototype model.

Geometry and Movement

The geometric body parts link to the movement components that our robin displays. The following list shows the link between the two.

• Geometry: Sphere and cone
• Movement: Shake (Rotate Y), Nod (Rotate Z)
• The Torso
• Geometry: Sphere scaled along Y axis
• Movement: Bend (Rotate Z) – Moves with Feet
• Wings
• Geometry: Flattened spheres
• Movement: Lift (Rotate X)
• Tail
• Geometry: Extruded cube
• Movement: Wag (Rotate Y), Lift (Rotate Z)
• Feet
• Geometry: Modified cubes
• Movement: Bend (Rotate Z) – Moves with Torso

RobinCTRL circle is at the base of the character. These are its attributes.

The robin’s movement is controlled by the RobinCTRL, a circle at the base of the character. The added attributes inside of it (eg. Lift Tail, Wag Tail etc.) are connected to the corresponding rotation fields for each geometric component of the character. These rotation fields usually have a minimum and maximum rotation limit to avoid self-intersections.

The main rule behind the rotation of any character component is a sine wave:

$R&space;=&space;A&space;*&space;sin(S&space;*&space;\Theta)$

Where R is the rotation angle, A is the amplitude, S is the speed and $\Theta$ is the angle linked to the current frame. The amplitude and speed can be set from the graphical user interface for each character component. The current frame is usually the one being considered for the addition of a key. To better understand the process, let us have a look at the GUI and the python code behind it.

The GUI and the Code Behind It

Plugin GUI

The GUI has the following components:

• Reset Robin button
• Clears all the key frames of the animation
• Animation Start Frame
• Sets the start frame for any animation component
• Animation End Frame
• Sets the end frame for any animation component
• Component tabs
• Feet control the hopping movement
• Torso controls the bending of the torso
• Wings controls the flapping of the wings
• Tail controls the wagging and lifting of the tail

Each tab usually has fields for setting up the frames per movement, the amplitude and speed. The frames per movement refers to the number of frames necessary to perform that action once. A hop taking place over 10 frames is faster than a hop over 20 frames for example. Speed can be used to tweak this effect of course.

In the case of the Feet tab, once these settings are typed into the fields, the user can press the Hop button, which calls the following method.

#Head nodding animation
robinCtrl = cmds.select('RobinCTRL', r=True)
getAnimationStart()
getAnimationEnd()
flip = 1

for i in range(animationStart, animationEnd, nodHeadFrames):
flip = -flip

for j in range(0, nodHeadFrames, 1):
if (i+j < animationEnd):

else:
break


The RobinCTRL circle is first selected. Then the animation start and end frame values are extracted from the GUI.  Next getNodHeadFrames(), getNodHeadAmplitude(), getNodHeadSpeed() extract the frames per hop, amplitude and speed values from the GUI. The flip parameter is a boolean which decides whether the movement should be symmetric or not (ie. hopping up and down, rather than hopping up and then jumping to a down pose briskly).

The two for loops that follow travel through the frames of animation and set a keyframe at every step. The inner loop is the one that creates the individual hopping movement, while the outer loop makes sure all the frames between the start and end frames are covered. The $\Theta$ angle, which controls the point on the sine wave we’re currently at, goes from 0 to $\pi$ in nodHeadFrames steps. This is the parameter set by the getNodHeadFrames() methodThe last two lines from the inner for loop set the calculated headRotation in the NodHead field of the RobinCTRL circle controller and add a keyframe to this new value.

Similar steps can be seen in the remaining movement component tabs. Individual methods were written for each tab, but I believe they can be reduced considerably as the current code is repetitive. For future work, it would be nice to introduce techniques for creating animation sequences (eg. hop for 30 frames, stop, look around etc.). Also, saving parameter settings would be useful for recreating popular animations like flying or whatever the user enjoyed doing.

The code and Maya file are available on GitHub.

Please have a play and tell me what you think! Thank you!

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# E-StopMotion

Digitizing stop motion animation has been my Engineering Doctorate project for the past three years. The aim was to simplify the workload for artists and offer them tools to bring their handmade creations in a 3D environment. The following video shows a simple pipeline for digitizing characters from the game Clay Jam, by Fat Pebble. This is now published work and open for film and game companies to use.

Publications

[1] Anamaria Ciucanu, Naval Bhandari, Xiaokun Wu, Shridhar Ravikumar​, Yong-Liang Yang, Darren Cosker. 2018. E-StopMotion: Digitizing Stop Motion for Enhanced Animation and Games. In MIG 18: Motion, Interaction and Games (MIG 18), November 8-10, 2018, Limassol, Cyprus. ACM, New York, USA, 11 pages.  [PDF]

Hellidropter says Hi!

Abstract

Nonrigid registration has made great progress in recent years, taking more steps towards matching characters that have undergone non-isometric deformations. The state-of-the-art is, however,still linked more to elastic or locally shape preserving matching, leaving room for improvement in the plastic deformation area.
When the local and global shape of a character changes significantly from pose to pose, methods that rely on shape analysis or proximity measures fail to give satisfying results.
We argue that by using information about the material the models are made from and the general deformation path, we can enhance the matches significantly. Hence, by addressing mainly plasticine characters, we attempt to reverse engineer the deformations they undergo in the hands of an artist.
We propose a mainly extrinsic technique, which makes use of the physical properties we can control (stiffness, volume) to give a realistic match. Moreover, we show that this approach overcomes limitations from previous related methods by generating physically plausible intermediate poses, which can be used further in the animation pipeline.

You can follow the research progress on Vimeo and GitHub. This is a work in progress project, in collaboration with the Centre for Digital Entertainment at University of Bath and Fat Pebble, under the supervision of Darren Cosker.

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# Cube Limbo

While tutoring Fundamentals of Visual Computing at Bath University, I got acquainted with WebGL and ThreeJS. This is a quick weekend project, where cubes of random sizes and animations do the limbo. The students laughed, so mission accomplished!

The main idea is to create a state machine for the procedural animation. Each cube needs to be created, then translated towards the limbo bar, then scaled down to fit underneath it, scaled back up and translated out of view. The snippet of code below gives a glimpse of all the states needed. We start off by setting the cube creation mode to true.

 var cubeCreationMode = true;
var cubeScaleMode = false;
var cubeTranslationMode = false;
var cubeSquashMode = false;
var cubeSquashTranslationMode = false;
var cubeStretchMode = false;
var cubeRemoveMode = false;

ThreeJS, a wrapper around WebGL, works between the script tags in the html file where our application is. This application is mainly composed of two functions, init() and animate(). The former is used to initialize the camera, the scene and any objects needed to be rendered in it (eg. floor and limbo bar), lights and the WebGL renderer. The latter function is used as a loop, which updates the rendered scene at a number of frames per second (eg. 30 fps). If objects move in the scene, they’ll be drawn at their new location.

function animate()
{
requestAnimationFrame(animate);
makeMove();
renderer.render(scene, camera);
}

As it can be observed in the function definition above, animate() requests a new frame to be drawn, makes a move on the objects in the scene and then renderes the current frame.

Depending on the current true state, the cubes in the scene will have a different movement pattern. For example, the code below shows how a cube translates, when the cubeTranslationMode is true.

If the cube is still within the appropriate distance from the limbo bar, it will translate towards it. Also, the little side to side movement of the cube is given by a rotation around the local x axis. Cosine of time was used for the transaltion in the hope of creating an ease in and ease out effect, which doesn’t seem very noticeable.

if (cubeTranslationMode)
{
distanceToStop =  tempCube.position.distanceTo(cubeTargetPoint);
if (distanceToStop > cubeStopDistance)
{
//Keep translating
tempCube.position.x += Math.cos(clock.elapsedTime) * cubeTranslationSpeed;
//Keep rotating
if (cubeCurrentRotationIteration <= cubeRotationIterations)
{
tempCube.rotation.x += cubeRotationDirection*cubeRotationSpeed;
cubeCurrentRotationIteration++;
}
else
{
cubeCurrentRotationIteration = -cubeRotationIterations;
cubeRotationDirection = -cubeRotationDirection;
}
}
...
}

Similar snippets of code can be written for the rest of the animation states. One must remember to set the current flag to false when the animation segment has finished. In this example, once the cube is close enough to the limbo bar, cubeTranslationMode is set to false, while cubeSquashMode becomes true.

Reference: ThreeJS scripting

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Research & Coding

# MIG18 in Cyprus

I wake up at 6am with the sound of a mandolin in my ears. Russian voices can be heard from next door. I turn in my bed thinking ‘For a five star hotel, they don’t have thick enough walls.’ I finally get up and look outside, ‘but they do have a five star view.’

View from my room at St. Raphael

This is how my first day in Limassol started, at St. Raphael’s hotel, with a spectacular view and russians playing the mandolin. The sea looked so inviting, but I spent most of the day preparing my presentation. ‘Ah, this is torture, but it must be done.’

Although I’m in my natural element walking around the stage pretending to be a pirate and giving orders to my ship mates, I don’t like presentations, at least not formal ones. I guess I haven’t convinced myself yet that although people may judge, they really want you to succeed. I didn’t know what to expect from the conference I was about to attend, I just knew that the mustard suit my mum made me buy would be like a kangaroo sticking out from a flock of sheep.

The next day (08/11/2018) was the first day of MIG18 (ACM Siggraph’s Motion, Interaction in Games conference). I was in limbo state, not too nervous, not too calm. I went to the sea to rest my thoughts, as the sun was slowly lifting its head over the morning sky. My room card had stopped working by the time I got back from the sea and a light breakfast. Reception quickly sorted it, but it was 8:30 and I had to dress up for my presentation at 9:00. Guess what? The maid was in the room, making my bed. ‘Erm, do you mind if I change in the bathroom.’ I said, holding my mustard suit, which had been dry cleaned the previous day.

It turned out I didn’t have to hurry so much, Prof. Nadia Magnenat Thalmann wanted to swap presentations with me, since she had a plane to catch. It’s funny that she presented exactly what I wanted to hear: a way of classifying (salsa) dancing using simple motion features. Yes, salsa can be decomposed into simple patterns of movement, emotions can be decomposed into action features. What else can be simplified and understood about the human nature? What are the invariants to human perception as Rogelio Cardona-Rivera implied in his wonderful keynote on The Science of Game Design. I go deeper and ask myself, what are the simple patterns of movement that unite us all, that move us to tears, that enhance our empathy towards one another. Can we use technology to understand such patterns and, subsequently, understand one another?

Machine learning is the hot topic of the day (for how long I wonder). It also was ridden all over the conference, with topics like Data-driven Autocompletion for Keyframe Animation by Xinyi Zhang et. al,  Physics-based Motion Capture Imitation with Deep Reinforcement Learning by Chentanez et. al, two very good key notes on ML by Daniel Holden and Jungdam Won etc. Although my initial attitude towards ML was skepticism, I must confess I finally saw what all the fuss is about. If my interest is to understand behaviour from the intrinsics of a character outwards, ML was doing the opposite.  Since capturing the complexities of human nature in a closed form equation is virtually impossible, why not humbly understand its approximations by analyzing as many people as can fit in a database? Yes, I’ll think more about it…

Now for some cheese:

The number of surprises was endless, but I’ll just mention a few wonderful events and people that made my experience at the conference worthwhile. I loved how friendly everyone was, people really were curious and wanted to help eachother out. The organizers, Panayiotis Charalambous, Yiorgos Chrysanthou, Ben Jones and Jehee Lee were very welcoming and down to earth, always making sure we were having a good time. I loved Matthias Muller’s keynote on Physics Based Dynamics. I realized I had quoted him in my thesis as he was awkwardly receiving a fertility totem as a thank you gift for his talk.

I was humbled and happy to meet the charming, smart, warm and confident Xinyi, Athomas, Bea, Anastasia, David, Usman, Luis, Loic, Daniel, Philipp, Dario, Yuri, Jason and many, many others :). Sorry I haven’t managed to talk to everyone!

MIG18 people (picture taken from MIG18 Facebook Page)

Last but not least, the day out in Nicosia and the two amazingly cypriot dinners really got everyone to socialize and loosen up. Do I even need to mention the cypriot dancing? It was nice to see people volunteer and do curious glass balancing or oversimplified zorba moves around the restaurant. It was funny that every type of dance had some form of courtship: courting in the wheat field, courting by the well, showing off glass balancing in front of the young bride to be :))

Our Nicosia tour guide reminded me of a confident cypriot granny who knows exactly what to put in her meze dishes. She walked us around Nicosia and shared the city’s disputed history. Probably the most haunting moment was when we saw the green line wall separating the greek and turkish cypriots. The police there seemed friendly enough, however, which gives me hope. I loved the quaint, narrow streets with fairy lights illuminating the pavement, the local crafts shops and the friendly people around. It was nice to see young people trying to revive the old market place with art.

All in all, MIG18 in Cyprus was awesome and I hope to come again! Thank you for the adventure!

Green line wall between the greek and turkish cypriot sides of Nicosia.

Green line wall police seem ok. 🙂

Our Nicosia tour guide.

Local wax crafts shop.

The cool kids in the local market in Nicosia.

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# Expressing Emotions Through Procedural Animation

We know from Paul Ekman that there is a baseline for human emotions. We all express the 6 basic emotions (joy, sadness, anger, disgust, fear, contempt) in more or less the same way. This personal inquiry looked at how we can abstract emotions to a language of trigonometric functions. Is there a link between the energic, soaring joy emotion and the upwards movement of a sine wave? For this initial stage of the project, I used simple primitive geometry.

Abstract

The complexity of emotion and thought an individual can contrieve is far from being clearly defined. As the philosopher Winwood Reade suggests however, “while the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty”.  This statement reflects the idea of general available guidelines, common to all individuals, through which they connect and understand one another. These rules are also found in the area of expressing emotions. We can simply describe  basic patterns for anger, contempt, disgust, fear, joy and sadness, thus we can make an attempt in defining these templates in a mathematical form. The current study focuses on finding the appropriate elementary functions that contribute to creating, so called, target factors, which convey characteristics of the six aforementioned emotions.