Sunday, January 27, 2008

The Beauty of the Fall

The beauty of the Püterschein system is, as you can see in this picture, that the puppet assumes very natural positions with no human intervention. I just cut the string that held it up and it fell on its knees just like that! A true predecessor of inverse kinematics!.

It seems like it is praying for arms, looking intently at the cut rods that will give it the expressiveness it needs.

I cut an old broom stick to use for the arms, thinking that it was pine and it would save me some time if it already had a round shape. Ha! I don't know what kind of wood it is, but it was hard as oak and I have gone through a whole set of carbon steel blades just cutting it down to shape. It has taken me three full days to get them ready for testing! So much for saving time...

You can see the Creator now just standing naturally, again with only spine support. I did not pose it, other than bringing it down to contact a surface. Can't wait to have the entire body functional. In case you are wondering the "feet" will be (at least that is the plan) two slim inverted cones. We'll see how it behaves. As for hands it will have none in this iteration, since it will be all dressed up and have very long sleeves like the human performer in an earlier post:
you can see it here and in the original design so you get the idea.

This is a detail of the hip and waist rigging that holds and constrains those parts as the marionette flexes and moves.

After three days, a few cuts and sore muscles overall, the arms are close to ready. I've tested them and they move gracefully and have the needed range. Under the torso you can see the channel I gouged out to make room for a couple of screw eyes to pass the string that connects it to the waist and hip.

Next task: the HEAD! this will be interesting since it will have a wooden core or "skull" and it will wear a "self animated" mask, a fancy way of saying it will have some springs to react to any movement of the head. If I have time, which I doubt, I would like to put a micro-servo on the latex mask so that it can have a range of expressions in addition to the eyes. Lorena, who designed the original creature does not like the idea. Perhaps she is right. The simplicity of the spring solution, which we have demonstrated on performance gives such a varied range of expression to the Creator's face that adding more might be less. So there!

Wednesday, January 23, 2008

The Power of Tools

I started the Creator's torso by finding an appropriate block of wood. I had intended to use pine since it is soft and easy to carve, but I had none of the right dimensions. My only option was cypress, which I like a lot for its color and its pattern, but is is considerably harder and demands a lot of attention to the direction in which you can whittle it. That means you have to be really careful to follow the pattern of the rings and watch when it changes direction if you don't want your blade to get caught and possibly damage the wood, specially when you approach the final surface.

A very important thing when you carve, specially at the beginning when you apply a lot more force to approximate the shape you need, is to be able to hold the piece securely. There might be other techniques and of course you can improvise, but if you have access to the magnificent and versatile Jorgensen clamps, use them!

If it had been pine I could have done it with a set of X-Acto knives without much problem. But for any hardwood you need proper carving tools, I have found that Warren Tools 1 are an excellent choice. I have had my "traveling set"for over twenty years or more when I bought them to carve my first "professional" puppet out of basswood. I've kept that set like a treasure through many life changes and moving from continent to continent. I have lost many things but not this little box. True, there are finer and more expensive carving tools out there but here you have a balance between price, quality and workmanship.

I talk about tools often because I think that tools and the art they enable are inextricable linked, "...where form and function are most closely related as a way to understand and influence our most basic aesthetic and ethical decisions". 2 I also think that great tool design can only be achieved by someone who has mastered his or her craft and realizes the importance of the interface between your mind and the object you intend to create.

Whittling is not done much anymore since the advent of power tools, the same way that cooking (and eating!) has pathetically been replaced by TV dinners specially in American households and definitely in student's dorms. TV watching has taken the place of meditation and your organizer has replaced your capacity to memorize. All I can say is that the magic of discovering the shape that lies inside that block of wood as you approach its delicate surface is one of the greatest rewards.

At this point I need to refer back to something that Michelangelo mentions in one of his letters about the fact that he does not really "create" the sculpture (and remember we are talking about pieces like the Pietà and David among others) but simply uncovers or reveals that which is already present in the stone.

When I first read this as a young aspiring artist I took it as false modesty or as some sort of metaphor, but later on I found other references that made me pay attention, like the time when he goes to the Carrara quarry to look for a block to carve his Moses, and upon looking at the huge block of marble he says very disappointed something to the effect of "...damn! he is sitting down!" (he had already planned and sketched Moses standing with the tablets).

Some of Michelangelo's supposedly "unfinished" pieces, like the "Awakening Slave" or "Atlas" seem to me perfectly done and finished, and they clearly show the process of discovering what is "already there".

Now, this can be interpreted in a number of ways and I don't pretend to analyze nor can I offer proof that he meant it that way, but I can offer my own experience which I would like to share even knowing that some people will think me crazy.

Many years ago, me and my great friend and extraordinary artist Fernando de la Jara, entered a competition to create a monument for a fallen pilot. We decided to do an obelisk but with a twist (literally) that turned as it grew as a Fibonnaci series. The main body would be marble but the very top would be made with alabaster, and the shape of a human form rising towards the sky would be carved inside so that it would look trans lucid as the sun entered the zenith.

Well, my task was to carve a model out of plaster to present with the proposal. So I started by making a block inside a milk carton, traced the bottom square and the rotated and smaller square at the top and proceeded to carve away. First of course big chunks to approximate the overall shape and then as it got closer I started of course to be more careful taking occasional measurements.

A long time passed and I was by then taking very thin slivers of plaster since the form was already evident. But suddenly, after removing one more sliver a very distinct surface appeared, the quality of which you would not call plaster. This surface was very smooth, the color was slightly warmer that the cool white of plaster, more like ivory. First I thought it was a patch of different texture due to the mix, but I just kept "peeling" away the very thin "skin" that covered that layer. Of course in some parts I had to whittle out more to get there.

I was so surprised that I called my friend to verify that I was not simply fatigued. But we concluded that that in fact was the actual surface of the final shape that we were after. So I continued the process until all of the extra material was gone. I did not have to measure like I was doing at first, all I did was carefully shave until I found that surface. When I finished I had the twisted obelisk that we had planned to do. I know how absurd this sounds, how could that piece "exist" inside a block of plaster? I do have some rational explanation, but for now I will leave it at that.
to be continued...

1- The blades are made with high carbon tools steel. I find they hold their edge for a long time before you have to hone them. Of course it depends in the hardness of the wood you carve and the angle at which you "attack" the wood. They sell at any woodcarving supply place.
2- From my paper "Roboethics and Performance" which I will put up in Lulu after graduation in July. Krems rules prevent me from publishing before that.

Monday, January 21, 2008


The Creator's lower body as it stands today :-)

Even thought it is a far cry form being even close to finish, the Creator has already began getting an attitude. I had to re-drill some holes to balance the parts but overall feels good. It stands straight when held by the "spinal cord" and it seems very easy to make it move in a very natural way, as expected. After all I am following the master's instructions.

The picture on the lower left corner shows the back of the hips where you can see the misalignment of the channels that lead to the waist stays. It really bothers me but it does not affect the performance, only my self-esteem! Maybe the Creator gets a hip replacement operation some day.

Balancing act

The hip and waist assembled for balance

So far the hardest part has been to drill the holes through the Apoxie and line them up correctly. That sent me back to examine very carefully old unfinished puppets from Dwiggins archive. I learned a valuable lesson: the holes must be drilled BEFORE you shape the form (DUH!), otherwise lining up and holding the shape correctly in different axis becomes almost impossible. That means that the use of Apoxie for main body parts is not the best solution, since it would be a real waste to create first a block and then cut and sand it down.

That said I am very pleased with the look and feel of those two parts, which strike me as very "Japanese" in some way. The only un-japanese thing about them is the misalignment and lack of precision of some of the through-holes on the back due to the reasons explained above. No excuses, (Julie Taymor would be very upset).

The fondest memory I have after enjoying many days watching the construction of a Japanese Tea House by a master carpenter was how every single piece of assemblage, including those that would never be seen by anybody, were as perfect as the main "public" pieces. The sculptural quality and the loving care and treatment of the most humble of materials left a permanent impression on me. I have a long way to go.

Next in line is to attach the legs which are already temporarily assembled and test the lower body for problems. If everything goes well then I'll shape the legs to give the Creator that sophisticated look that I am sure it craves:)

Sunday, January 20, 2008

On my knees

There are so many ways to make legs and knee joints!

This is my first pass, I don't think will be the last until it is finished, polished, assembled (the hard part) and tested. I am using white pine, it has quite a bit of resin, which makes it hard to carve and sand but also means it is stronger.

At least it is not as hard or life-critical as the prosthetic knees that biomedical engineers have to fashion for their patients!

I used some of those knee models to make a sculpture and as we found out, it was the hardest and most exotic material (titanium-vanadium_+some other ellements I don't remember) we could ever work with! It was worth it, and also gave me an insight as to how strong and durable future cyborgs will be.

Brad Smith (left) and myself after sweating it out to create the sculpture from conception to delivery in a record three days! Now, why can't I work as fast for this project?

Brad and myself created this sculpture as a recognition gift for Dr. J. Crayton Pruitt, who had just donated 10 million dollars (das ist recht!) to the Biomedical Engineering Department of the University of Florida.

Dr. J. Crayton Pruitt, as pleased with his gift as UF was with his! 1

So we thought appropriate to use some of those vanadium knee parts to serve as the pivot point of the sculpture, the rest of which consisted of beautiful alabaster that slowed light as it absorbed it, as only alabaster can. The wood base was made with an exotic Brazilian hardwood and the plaque was made from aluminum scavenged from the Aerospace Engineering bin.

These are some examples. Imagine the possibilities!
Assuming you have the tools to make a dent or solder the critters.

1 He must have liked the sculpture because ever since then we receive (Brad and I) a yearly crate of delicious Florida wine from his own vineyard. Thank you Dr. Pruitt! :-)

Friday, January 18, 2008

Waist and Hip

The waist unit is finished except for the holes and restrains that will attach it to the hip. This piece was so much easier because I did not let the Apoxie harden and I was able to model it with my hands almost to the exact shape, so it only took a bit of sanding and polishing. On to the legs.

Thursday, January 17, 2008

Not quite Brancusi

After cutting most of the extra epoxy with the trusty old Dremel (the new ones are plastic crap!) I proceeded to sand and sand away from 80 to 1200 grit until the shape fit my template.

The hip is now smooth and polished and feels great to the touch. I think I will use it instead of wood since I think it has the proper weight. Once assembled I will know if the total weight is not too much for the medium servos that I plan to use.

After finishing this stage of the hip I will need to drill and install attachment points for the legs and the waist, which is the next piece.

Sculpting the model

Although I will probably use traditional wood for most of the body, I want to try to make models of the parts with Apoxie Sculpt and Apoxie Clay, some of my favorite sculpting materials for small models, prototypes or part replacements. The only drawback in this case might be the weight, but then maybe not in the case of the hip which needs to be heavier since it is the center of gravity.

I left the ball of clay harden a little too much and so after whittling away for a while I finally gave up because it went past the "leathery" state which is so pleasant to work with.

Now it is up to power tools to pick up. I'll do that in a couple of days when it has harden enough and does not gum-up the blades or the sandpaper.

I really like the line of Apoxie products. I recommend them to my students and I use them frequently. They are easy to work with , extremely durable and have good mechanical resistance. Not to mention shelf-life!.

I found a couple of containers that had a bit left and had been "lost" for over three years. They were on the humid and very hot environment of the Florida swamp. That is just the opposite of what they recommend; 'refrigerated and dry to extend shelf life'

Well, other than being a little harder at first, after kneading it for a few minutes they came back to life and behaved as expected.

Now, if they only gave me a discount for the plug :-)

Monday, January 14, 2008

Püterschein Time! state of the art

OK, so now, after careful consideration and encouragement from my mentor, Deborah Ascheim 1 the robo-puppet has gone from 5.5 meters to 45cm, quite a change in every respect. But I am liking it more and more.

Now I am in the process of re-designing the body and I can take advantage of the superb Püterschein 2 system described by W.A. Dwiggins 3 in his 1939 handbook "Marionette in Motion." published and authored by Dwiggins under the pseudonym "Hermann Püterschein"

The basic and extraordinarily simple idea is that when designing the mechanics of a marionette, you consider gravity as the only force operating on it, and that "...your function with the string is simply to control the motion that results from the pull of gravity.

Based on one of Dwiggins models as a starting point I proceeded to modify the proportions, center of gravity etc. to fit the Creator's body.

This sequence shows the progression from the original proportions of a female marionette body based on the Püterschein system and the modifications it went through to achieve the desired proportions. Figures 1-3 show the position of lead weights in the shin and the pelvis (grey markers). In figure #4 you can see (red dots) the alignment of the different parts of the body. Once the parts are constructed but before they are completely finished each one needs to be counterbalanced so that with minimum effort and resources (servos, number of strings) the marionette can achieve a maximum of expressivity.

This of course is a gross simplification but it is the starting template from which the basic blocks will be cut and shaped. After that a careful balance needs to be achieved between all the parts so that it actually let's gravity do most of the work.

This is Lilith, one of the many characters built and rejected by W.A. Dwiggins, although it is...perfect.

From: "a complete experimental Theatre in Miniature; the Dwiggins Marionettes" by Dorothy Abbe.4
the most beautiful and comprehensive book on the master's work:

1- Deborah Ascheim is an interactive installation and interdisciplinary artist that works with light, based on a long standing interest in networks: neural, electronic and social. She has an upcoming exhibition at beautiful Laumeier Park, check it out.

2- The Püterschein system in which Dwiggins describes in detail his own system for construction marionettes is a very hard book to find, since it is out of print or very expensive. I have the fortune of having a beautiful facsimile of the original produced by Dorothy Abbe and it has proved to be an invaluable resource for my project.

3- I find that Dwiggins work, considering the scope, quality and influence on the design world, is grossly underrepresented, on the web. The link I offered above which is one of the more complete (at least it mentions that he was a puppeteer in addition to an influential book and typography designer) attests to that.

4- You cannot underestimate the importance of Dorothy Abbe. If it was not for her and the extraordinary effort of many years that went into producing one of the most beautiful puppetry books ever, the world would remain in ignorance about the work of a Master. As a
typographical designer and former partner of "Bill" at the private Püterschein Hingham Press, she was privy to one of the great kept secrets in the history of puppetry. The marionette collection, the private theatre, tools, diagrams and plays designed and created by this exquisite crafstman .

The Control Device

After having explored different systems and constructed some prototypes (that you will see later) I found a very interesting paper by a group of researchers at Nanyang Technological University in Singapore. The paper describes a very similar project in terms of actuation that has proved invaluable in understanding, among other things, the relationship and computation between the number of strings required and the degrees of freedom (DOF) desired.

I've since then contacted Professor I-Ming Chen of the School of Mechanical and Production Engineering at NTU, who very graciously offered to release their design so that I can integrate it to mine and suggested a possible collaboration as well. Thank you Dr. Chen

On the robo-puppet, the wires that would normally go to the handheld device, (sometimes called airplane control due to its cross shape) are driven by a series of servo motors, which wind or unwind the strings to achieve the needed posture. We will call the strings the actuators.

There are three different functions the strings perform.
a) support or constrain/reference.
b) movement control
c) special effects.

Since the puppet is basically stationary within the world (it does not go anywhere except your mind!) the support strings have a simple function and will probably only have an up-down movement. The reference string, will allow the puppet to bow and stand straight. As it name implies all other strings reference this string. This is taken from traditional Chinese marionettes and is called the backbone.

The motion control strings control the head and the limbs. Because the character makes ample and sweeping movements with his arms I originally considered controls mounted on swinging devices, which would function as the plucking of the strings do in traditional marionette control.

However, since the rig needs to be portable as well as easy to assemble, not to mention cost considerations I have opted, at least for now, for a linear extension that can be easily detached and does not need additional motors for swinging. An added benefit of this solution is that it provides faster response. It contemplates stationary arms in the control device, which go as far as the limit of the puppet movement. The servos at the end of the arms would control a wire loop that simulates the string plucking of a puppeteer.

3D simulation of control rig showing linear extensible arms and servo driven pulleys

After consulting with Dr. Antonio Arroyo 1 and Dr. Eric M. Schwartz I decided to add additional loop controls at the waist level to increment the degree of expressiveness of the puppet’s body language as well as install spring and/or elastic counterbalance and damping devices to minimize the inertial deviation of the limbs as they move rapidly into position.

My first basic prototype

Once the system is in place, the puppet, the control hardware and the software, it is necessary to train the puppet by establishing neutral, initial and target postures that can express meanings and range of emotions. This is similar to the numerous cell or keyframe elements that a conventional cel animator or “claymator”2 would have to prepare to follow a script. These groups of keyframes (one for every joint) would be called upon according to the response required by the sensors and their interpretation by the neural control program 3.

Some of the considerations that must be taken into account to perform the initial set of calculations include:

- The number of links in the system
- The link length
- The mass
- The center of mass
- The inertia moment
- The joint viscosity

1- Dr. Arroyo is the Director of the Machine Intelligence Lab (MIL)at the University of Florida and it is my designated mentor for this project. Dr. Eric Schwarz is Associate Director of the MIL at the University of Florida and gives me advice as a mentor as well.

2- Clay animation is one of the many forms of stop-motion animation where the clay is hand-shaped for every frame to achieve the illusion of movement. The term Claymation was popularized by animator Will Vinton who used it as his trademark. However it is now commonly used in the English language to refer to clay animation.

3- Input /Output into a simple neural net.
The input to the system consist primarily on tracking (image and pattern recognition), on the information provided by the ambient sensors, such as movement, light, sound, proximity, etc. This input is correlated with the matrix representing the mindset of the puppet; his “vision of the world”
The output affects the actuators (motors, sounds, lights), ambient displays and control systems.

The poor man's space-age materials

Although I do not need such strong composites as I was previously using due to the downscale of the puppet I still want to go through the discovery process that I found very valuable as a DIY "instructable" as they are now called.

I must mention that I still plan to use the material I prepared, except now I will utilize it to carve and build the entire body of the robotic-puppet instead of just the limbs.

Original requirements.

Regarding the construction of the limbs, a promising construction technique came from an unexpected source. A Near Space article 1 on boom construction for near-space aircraft and ballonSat 2 frames and rigs described a simple, inexpensive and very strong method for a lightweight composite boom, which I adopted after some preliminary tests.

The following pictures show some of the materials that I am currently using to construct the limbs of the Creator. After some comparison tests with other methods and materials, I have found this to be the optimal structural material that will comply with the many requisites of the performing object.

Limb Test Construction Process

Limbs are currently made of a composite material consisting of 3/4” extruded polystyrene foam sandwiched between either 1/34” triply birch plywood, and/or 1/4” balsa wood. Styrofoam, as is commonly known, has a high compressive strength foam very resistant to water penetration which is a consideration in a high humidity environment such as Florida where we currently live and work (the swamp!)3.

Weight-strength-cost are important considerations. Given the size of the puppet (approximately 5.5 meters) and the fact that it will be controlled via servo motors, it is imperative that the structure be as light as possible and at the same time be able to withstand the forces applied to the different joints.
The puppet must be easily assembled and disassembled for transportation and performance and be able to survive the abuse associated with these events.

The foam and plywood are glued with 5 min epoxy and held together between 2x4’s to distribute the pressure evenly.

I use Jorgenson’s wooden pressure clamps and can’t say enough about them. These ingenious clamps can vary the angle of pressure precisely. Using almost any other type of clamp will result in the sandwiched elements sliding out of alignment due to the viscosity of the glue while drying.

I found that both the birch plywood and the balsa wood, when epoxied to the styrofoam have an enormous resistance to fracture, you cannot break them with your hands alone. The difference is in terms of surface, since the plywood is smooth and hard and the balsa is very soft and easily damaged.
In terms of weight they end up the same due to the different thickness-weight ratio. At every joint an additional element like a plastic or metal tube or bushing that will support the axis, bearing and constrain the joint must be securely attached.

So far I am satisfied with the light weight and rigidity of this construction technique.

1- Nuts and Volts, September 2006, p.78

2- BalloonSAT Basics
- Sounding balloons 1200-1500 grams filled with helium
- Rise to altitudes over 100,000 feet
- Parachutes attached to payloads
- Modules include:
- Communications - flight and ground, radio, TNC and GPS
- Science payloads – weather data, Geiger counter, particulate sampling, ozonesondes,
- Imaging payloads – digital or analog cameras
- Flight Computer – data transmission or storage

3- Talk about humidity. Since we moved from the Apple to the swamp we have had to deal with 80-90% humidity on any given day, excluding storm or hurricane season where nothing applies! Since my "dirty workshop" (where wood cutting, sanding, spraying etc. happens) is located on a shed in the backyard, even though I insulated the whole structure, humidity seeps in at an incredible rate. I bought a pump-dehumidifier and the thing extracts around 5 gallons of water every 24 hours! If it not were for that essential piece of equipment you can imagine the state of materials and tools. In fact, what prompted me to buy such a thing was the sorry sight of my precious tools rusting and everything else deteriorating no matter how much you clean and oil etc.
This is the "clean corner" of the "dirty-shop"

The most absurd thing is that nobody sells dehumidifiers in Florida! on the contrary, they sell humidifiers!!??? what is up with these gators! Can't wait to go to higher ground :-)

The construction of the character

Throughout pre-historic and recorded History, tools and the art they enable are inextricably linked. Synergy being a basic principle of all interactive systems points to the study of tools and technology, where form and function are most closely related as a way to understand and influence our most basic esthetic and ethical decisions.

In this performative event, emphasis is put on having the technical design aspects of the piece be one and the same with the artistic process. I am, after all, selecting the equivalent of the canvas, the pigments, the color scheme and laying down the fundamental materials with which to enable the alchemical reaction that constitutes the creation of a work of art. By choosing to enable the function that follows the form, I hope to find the primitive elements that when combined, emerge as more than the sum of their parts. Having set a goal to achieve in a span of time and place I am more interested in the steps that we take and the moment we live in the present.

This and the following posts are simply a record of a process. Sometimes we get lost in the details, as we should, only to emerge with a better understanding of the intricate relationships between form and function. As a disclaimer I should mention that although I don't purposely endorse some of the products that appear in the pictures, I find it a very valuable information about the craft. I remember as a young cinematographer interested in SFX, how I studied trade magazines, with a magnifying glass in hand (or in eye?) to try to discover what materials did so and so used in some film or theater piece that had amazed me. So these following posts will serve the same purpose.
The expressionistic head is not supposed to be seen in flat light like this but in a very dramatic and dark (as in moody) illumination

The head of The Creator was originally modeled in clay. Two plaster-gauze layers applied as a base, followed by 3 layers of papier-mâché, pretty standard stuff. Although very resistant and easy to control mechanically by hand, this method of construction proved to be too heavy for the servos I intended to use, given the scale of the puppet (5 meters high).

Although not directly inspired by it (in fact we had never seen this particular piece before this research) it was interesting to find this other mask creature designed by Jean Cocteau which uses similar materials and constructions techniques and embodies a similar tragic spirit.

Jean Cocteau and his mask for Oedipus Rex1 and The Creator's child

Since we have reversed the relationship puppet-performer and the puppet will be 45cm high, weight and servo power is no longer an issue. This has changed considerations such : weight and mechanical resistance, safety and ease of casting, machining etc. not to mention price! (I am very pleased with this last item:-)

The question now becomes if the physical scale alters in any way that other "construction of the character"?

Stanislavsky: "...the actor learns what he must discard, what in himself he must overcome, which of his personal traits can serve "as building material for the construction of the character."2

Although the physical character is "small", the psychological impact will be expressed by projecting a large real-time video of The Creator as it controls its World. That will be the test of the scale decision.

1- Arthur King Peters Jean Cocteau and his World, The Vendome Press, NY, 1986 p.95 This mask was created for the 1952 Paris production with Stravinsky.
2- "Stanislavsky in Focus" by Sharon Marie Carnicke, p.163, Routledge 1998

The Creator character

The puppet is being constructed as a marionette. This approach allows for a rich and varied kinematics1 and dynamic behavior2. Mechanically it resembles a cable-operated rigid body (such as a complex crane). The puppet consists of a series of joined rigid elements, which correspond to the simplified mechanism of a human body.

The non-verbal language of the puppet is constructed as a neural net of three simple primitives that control gestures (limbs, hands), speech (the puppet “vocal chords”), and expressions (body language).3

The essential role of these primitives is to build a vocabulary of behaviors4. The combination of these primitives can give rise to more gestures with different meanings and evolve complex behaviors by sequencing, superposition and inhibition5.

The mechanical design consists of determining the number of limbs, type of joints, degrees of freedom (DOF)6 of the joints and other movable pieces. It is not defined yet how many strings will be used to control the marionette, but probably between 8 to 12 will be enough, depending on various factors including number of segments of limbs and cost and time of development for both software and hardware.

1- In physics, kinematics is the branch of classical mechanics concerned with describing the motions of objects without considering the factors that cause or affect the motion. By contrast, the science of dynamics is concerned with the forces and interactions that produce or affect the motion. The term "kinematics" derives from the Greek word ______, meaning "to move".

2- The basis of kinematics is the choice of coordinates that describe the position(s) and/or orientation(s) of object(s). The time derivatives of these coordinates correspond to velocities and accelerations. An important component of kinematics is differentiating position to obtain the velocity or acceleration, and vice versa, integrating velocity or acceleration to obtain the position. Another key component of kinematics is converting between different sets of coordinates that describe the same motion. Both of these components are fundamentally mathematical methods, and are not based on physical principles.

The simplest form of kinematics is the description of point particle motion (translational kinematics). The description of rotation (rotational kinematics) is more complicated. The state of a generic rigid body may be described by combining both translational and rotational kinematics (rigid-body kinematics). The most complicated case is the kinematics of a system of rigid bodies.

In all of these cases, the most useful choice of coordinates may be determined by constraints on the motion, or by the geometrical nature of the force causing or affecting the motion. For example, it may be convenient to describe the motion of a bead constrained on a circular hoop by its angle on the hoop. Similarly, it may be practical for calculations to describe the motion of a particle acted upon by a central force using polar coordinates. (Source: Wikipedia)

3- Emotions as expressed by “matchstick” body language.

The question here is: how much visual information is needed to express character? Even though I have done motion capture sessions a number of times, it does not cease to amaze me the amount of “personal” information that is actually registered by recording the markers placed on our basic joints. Without the benefit of face expression, body shape (other than general proportions) and other elements that would seem to convey a great deal about a subject, the identity and some key “personality traits” can be immediately deduced or understood by the visual combination of a set of lines in motion.

Here is an example. Years ago I had to capture the movements of the entire team of the “A’s” of Oakland, then World Baseball Champions. I used a recent invention by a small startup called BioVision which used 4 cameras to record the position of reflective markers set at the joints of the player’s limbs as well as other locations like the chest, shoulders etc.

Reflective markers for motion capture (Source: Brunel University, London)

The position of these points of light were correlated with an initial calibrating position and sent as data to the program, which triangulated and calculated the 3d position of such markers. These positions were then transferred to a stick figure consisting of the same number of limbs and joints. The movement could then be played back. At the sight of the stick figures moving, my coworkers, who were all baseball fans, were able to tell immediately the identity of the character long before it made a move that gave away his role. Sometimes just the stance, the gait or a slight movement of the “body” would carry the personality, which was familiar to the observers.

Motion capture data applied to stick figures (Source: University of California, Irvine)

This experience made me think about what it is that constitutes that personality. How do we express emotions and how do we “read” other people? It seemed that by stripping away all the particular characteristics of the physical body except the basic proportions and movement (time-displacement or space-time of the body) we could convey the story in an even more direct way. The empathy and identification was, in fact, enhanced. By establishing a direct connection with some part of our psyche or perhaps our animal brain, it gave new meaning to the phrase “judge of character”

4- McNeill, David, Language and Gesture, Cambridge, University Press, 2000

5- According to David McNeill there are four kinds of gestures that are usually distinguished:
Symbolic gestures represent some widely recognized conventionalized meanings with body configurations and movements. For example, a thumbs-up gesture indicates agreement.
Deictic gestures are those that point objects in the environment with arms and figures. They may also be used to indicate unseen, abstract or imaginary things.
Iconic gestures are some pictorial gestures intuitively representing physical entities in the world.
Metaphoric gestures represent abstract objects or concepts.

6- In mechanics, degrees of freedom (DOF) are the set of independent displacements that specify completely the displaced or deformed position of the body or system. This is a fundamental concept relating to systems of moving bodies in mechanical engineering, aeronautical engineering, robotics, structural engineering, etc.

A particle that moves in three dimensional space has three translational displacement components as DOFs, while a rigid body would have at most six DOFs including three rotations. Translation is the ability to move without rotating, while rotation is an angular motions about some axis.

Creature in Performance

Here is Lorena trying out her Creature creation in our very cramped rehearsal studio (we wish:-). Click on the image to see her sweat off a few pounds. No kidding, that is the actual speed at which the Creature moves!

Theater and performing arts are collaborative in nature. In this work as in many others I collaborate with my wife and partner, Lorena Paola1, an accomplished actress and designer on her own right. Our points of view are sometimes diametrically opposed and this means we must find the focus where those points converge in a “pivot of interest”2 as a means to stabilize the vision enough to be perceptible and understandable at some level to an audience that stands in for the community of the “theatrum mundi”3, where we express the cultural and political concerns of the self in relation to the world.

By bringing into the stage streams of everyday actions by people willingly or unsuspectingly captured by the panoptic4 gaze of our modern “society of control” as building blocks of the Creator’s alchemical process, we intend to establish the idea that all actions are performance and the implication that by performing those actions we long for the long lost promise and plenitude of eternal life.5

1- Lorena Paola is a multifaceted artist, working in theater as an actress-director-playwright-choreographer. She is also a sculptor and a glass artist, costume, mask designer and model-maker and is involved in every facet of production for her theater company “TeatroNuestro” of which she is President.
Lorena studied acting in her native Chile, Photography in Munich, Germany, Music Theater and Dance at “Steps” in New York and Jazz at Broadway Dance Center. She was Drama Instructor for the Hispanic Cultural Heritage Center in Miami and acting instructor at New World School of the Arts.

As a playwright her work has been performed in Pappenheim, Germany, at Florida International University in Miami as well as at the Digital Worlds Institute where she wrote, choreographed and acted in an international collaborative piece with Chile.

Her last play “Workshop of Dreams” was premiered as part of the International Theater Festival in Puerto Montt, Chile in July 2004.

- Fernand Léger wrote that he wanted “to conceive of objects as the pivots of interest, objects so beautiful that they have enormous spectacle value.”

3- In Calderon’s “Gran Teatro del Mundo”, he has the world itself state that it only obediently executes that which, although brought about or created by it (the world) the miracle belongs to the actor that enacts his/her given role. There are no spectators in Calderon’s play. Each of us is an actor, and thus responsible for our own image and creation.

4- The Panopticon is a type of prison building designed by English philosopher Jeremy Bentham in the late eighteenth century. The concept of the design is to allow an observer to observe (-opticon) all (pan-) prisoners without the prisoners being able to tell if they are being observed or not, thus conveying a "sentiment of an invisible omniscience." (Wikipedia)

5- In Lacan’s essay about the “mirror stage” (le stade du miroir) he describes the process of identification with an outside entity as "insufficiency to anticipation – and which manufactures for the subject, caught up in the lure of spatial identification, the succession of phantasies that extends from a fragmented body-image to a form of its totality that I shall call orthopaedic – and, lastly, to the assumption of the armour of an alienating identity, which will mark with its rigid structure the subject’s entire mental development" (Lacan, Écrits (rvd. edn., 2002), 'The mirror stage', p. 5).

Once the instrument is created...

In most of my work I look for the synergy between art and the science of materials, technology and other disciplines. Nowhere do I find more inspiration and practical wisdom, as in the writings and sketches of Leonardo, whose brilliant engineering mind created the scaffolding for some of the most enduring artifacts of our world.

In particular, his studies on the “anatomy of machines” has been instrumental in providing me and countless others with detailed explanations and solutions to the many problems associated with complex mechanical and “life-like” movements required in robotic-puppetry work.

In his Trattato degli elementi macchinali, (Madrid Ms.) Leonardo goes into great detail analyzing a great number of mechanical components which he regarded as the “organs” of machines. In a series of superb illustrations of such mechanisms we can see and study not only the solutions but the process of creation of his extraordinary mind.

Leonardo applied the same systematic analysis of machines to human and animal bodies thus abstracting and clarifying principles of geometry, movement and force, using quantitative methods to study their performance and deriving from such studies innumerable mechanisms which are a constant source of inspiration and function, in many cases as a conceptual blueprint, like this anatomical drawing of the base of the skull, which resembles the gravity and elastic driven mechanism of my puppet "Pancho" leg joints.

Sunday, January 13, 2008

Creator and Creature

These animations originally showed the scale of the Creator and Creature. It was not an accurate representation of the environment that I intended to create but a sketch to give some idea of the relationships.

After a reality check based mostly on finances and time-constrains and after careful consideration with my mentor, I decided to reverse the relationship, that is the Creator is now the smaller figure and the performer or Creature is life-size. This does not of course solve the complexity of the proposition, but at least makes good use of the economies of "scale":-)

A very interesting and valuable result of this decision is that the Creator's metaphor is more accurate as it better represents the post-apocalyptic homunculus which he was always meant to be. As it diminishes in size, like all electronic and robotic devices do, it will exert invisible control as it becomes the Environment.

The term homunculus appears to have been first used by the alchemist Paracelsus. He once claimed that he had created a false human being that he referred to as the homunculus. The creature was to have stood no more than 12 inches tall, and did the work usually associated with a golem. However, after a short time, the homunculus turned on its creator and ran away. The recipe consisted of a bag of bones, sperm, skin fragments and hair from any animal of which the homunculus would be a hybrid. This was to be laid in the ground surrounded by horse manure for forty days, at which point the embryo would form.

The Laboratory

The Creator's laboratory was inspired by De Viribus Electricitatis in Motu Musculari (1791) Luigi Galvani’s experimental apparatus and machines for the study of animal electricity.

The narrative occurs in a lugubrious laboratory, which resembles an alchemical dungeon/post-apocalyptic prison. The beakers and flasks, which we see in the background receive external "live" data streams and act as “time containers” and communication channels with a world that has been, is or could be. They represent both the Creator’s experiments in creature building and the raw material for his ongoing projects.

Inside the beakers and flasks that crowd the claustrophobic environment, float homunculus in various states of development and raw digital materials from which the Creator takes the elements for his creations. This “digital clay” becomes part of the DNA of the creatures and as such has unpredictable consequences once it is “released” into the world.

Some of these beakers and flasks act as “time containers” in that they show scenes of a world that has been, is or could be. As the digital bits and pieces of this data flow through the communicating vessels in the laboratory and recombine, some nightmarish visions appear projected through the frog-like creature and other specimens that hang in the background. They represent the Creator’s experiments in creature building. Occasionally, the creature’s muscles twitch, in a sort of digital-galvanic response to the influx of information, and excrete the contents into the surrounding area as processed media.

Galvani (1737–1798) was an Italian physician and physicist who lived and died in Bologna and who discovered that muscle and nerve cells produce electricity.
He coined the term animal electricity to describe whatever it was that activated the muscles of his specimens.
He regarded their activation as being generated by an electrical fluid that is carried to the muscles by the nerves. In the same manner, the electronic "fluid" flows through the network and feeds the Creator's mind.


The Creator inhabits a symbolic world where every line, every color and every shape or form must mean something. The Creature needs to adapt to this world. It uses the elements around it to communicate concepts such as moods, feelings and desires.

The center of the Metatron, where the Creature is conceived by its Creator is made of light. In a rough schematic form I am representing it by the color wheel in the center.

As the Creature moves about the Metatron and intersects or interferes with certain points, colors, directions of travel etc. the Creator interprets it and (hopefully) reacts accordingly.


The geometry of the Metatron is used as a computable control surface to determine the position of the Creature at all times. This positional information is used among other things to control the gaze of the Creator and respond to the actions of its Creature.

There is a primary and secondary color coding that on the one hand simbolizes the nature of communication between the Creator and its Creature, that of the wavelenghts of light, which act as channels of information.

The external circles represent the limits of the world both physical and as a symbolic construct. There is nothing beyond those limits but the void, the forbidden territory.


The floor plan of the Creator's World is a Metatron’s cube, which is in a way a two dimensional expression of the tesseract. Like in Alchemy, it serves a similar purpose of establishing the boundaries as well as the regions within which the Creator creates its Creatures.

Metatron is primarily the name of a primordial Angel in Judaism, and some scholars suggest the name means ”keeper of the watch” or “one who serves behind the throne”. In early kabbalist scriptures, Metatron supposedly forms the cube from his soul. This cube can later be seen in Christian art, where it appears on his chest or floating behind him.

Crucifixion (Corpus Hypercubus)
by Salvador Dalí (1954) Metropolitan Museum of Art.

Metatron's cube is also considered a holy glyph, and was often drawn around an object or person to ward off demons and satanic powers. This idea is also present in alchemy, in which the cube was favoured as a containment circle or creation circle.