LIGHTS OUT / IS IT OVER

May 10, 2010

Is It Over opened last Thursday to a buoyant response from the public. Although the space was still rather damp, everyone’s work felt thoroughly physical, bold and highly considered.

The exhibition allowed me to develop a site specific piece of work that dealt with lighting as creative process. Lights Out attempts to simulate a photoreceptive response within an dark confined space devoid of any natural light. Standing directly on top of the bunker I captured the surrounding environment light by photographing a chrome sphere at multiple exposures, compressing them into a single high dynamic range image (HDRI) in Photoshop. Inside the bunker I photographed some of the surrounding walls and floor, documenting the physical space. Then in Maya I began modeling a virtual bunker space using these photographic concrete textures and brought in the HDRI to illuminate the scene, creating organic structures that simulated a growth response from the floor to the ceiling. These ‘shoots’ are surrounded by square shaped leaves that reiterate the shape and physical restrictions of the bunker to natural growth. Ultimately the work succeeded in the process of taking natural light from the outside inside to drive a photoreceptive set of motions.

The title Lights Out refers to the WW2 air raids when the British people were told to turn off electrical lights so as to avoid being seen by overflying aircraft.

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RENDERING LIMITATIONS / LIGHTING RIG

April 29, 2010

Over the last two weeks I have explored the possibilities of using Maxwell Render to output my short film. My tests have shown positive results, however if I choose this rendering engine there are some major elements that need to be reconsidered within the framework of the animation. This sudden change has raised some technical issues surrounding my lighting rig that must be addressed immediately if I am to stay on track.

Because of Mental Ray’s long standing integration into Maya and its resulting flexibility, I could essentially rig any shader, geometry or particle to multiple light sources in world space. In Maxwell, lights are created by applying emitter materials to geometry from which real world photometric data is used to light the scene. Unfortunately this does not allow me to connect or ‘rig’ a light source to drive particles or simulations as I’ve been developing. At first this looked liked a major problem. Then, on gathering my thoughts and conscientiously going over my intentions I realised not only the potential but also the benefits of only using environmental Image Based Lighting in my scene.

Reading back over my blog I glanced over my Research Paper on HDRI and perceptual realism. I realised that this method was very much prevalent in my practical work as almost all of my scenes are lit with environmental IBL along with standard Maya lights. In Maxwell I found that creating an emitting light source in the scene doubled the render times which at this point in production is too heavy a hit to my timetabled workflow. When only using IBL the renders are quicker and the illumination is highly effective. So, the conclusion is that I will use one HDRI of an indoor environment which has multiple artificial light sources in it to light my scene. Getting the right amount of perceptually artificial light in my scene is very important particularly because the film deals with the prolonged effects of unnatural light.

I found these stats that highlight the amount of light around us in different environments, it is taken from;
http://jrscience.wcp.muohio.edu/nsfall00/FinalArticles/Isourmodernizingcultureki.html

Normal room 100-200 lux*
Brightly lit office or grocery store 1,000-2,000 lux*
Cloudy, January noon in Chicago 4,000 lux*
Spring sunrise 10,000 lux*
Summer early afternoon 100,000 lux*

*Lux is a measurement of light output or intensity (Rea 1993).

IS ITĀ OVER

April 28, 2010

I’m involved in a group exhibition called Is It Over held in a WW2 bunker behind Cafe Otto in Dalston. It opens next Thursday 6th May and will run for 5 days. The premise of the show is to invite artists to create work responding site specifically to the disused bunker which has laid untouched for 60 years. So far my work has taken 105 hours to render 220 frames (out of 400), I’m just hoping it will finish without error by next Wednesday. I will post a entry explaining the work and its processes shortly.

MAXWELL RENDER / PRODUCTION WORKFLOW

April 28, 2010

The process of rendering within computer graphics has a long history of attempting to simulate real world objects. For this to occur interactions of light and object have been at the center of generating believable imagery that adhere to the physical laws of electromagnetic radiation. My whole area of study has been consistently focused around this process. Therefore when I discovered an advanced lighting renderer for Maya, it felt only natural to focus my attention on it.

Maxwell Render is a rendering engine based on the mathematical equations governing light transport, meaning that all elements, such as emitters, materials and cameras, are derived from physically accurate models. Maxwell Render is unbiased, so no tricks are used to calculate the lighting solution in every pixel of a scene; the result will always be a correct solution, as it would be in the real world. Maxwell Render can fully capture all light interactions between all elements in a scene, and all lighting calculations are performed using spectral information and high dynamic range data.

I found when using Mental Ray to create photo realistic materials I was spending an extensive amount of time building complex shaders through extensive node trees in Maya. Even after hours of testing and tweaking, the results were varied and generally left me feeling a little unsatisfied. With Maxwell, the results are far easier to achieve and in my opinion appear more perceptually real. This can be put down to many things including linear gamma correction, physical camera distortions and real global illumination effects. However with all these positive points comes a variety of performance downsides. The render times are considerably longer than Mental Ray which is a major factor, especially in the world of animation. Even the 2:30min film I am currently working on will need a considerable length of time to render, here’s my breakdown;

– Approximated length of short film; 2:30mins, therefore 180 seconds.
– 180s with 24 frames per second = 4,320 frames in all.
– Averaging 30 minutes per frame render time (720p) at 2 frames p/hr = 48 frames p/day.
– 4320 / 48 = 90 days of render time.

Realistically I have under 60 days to finish this film, so already I’ve overshot the mark. If I bring this down to say 2 minutes, and shorten the render time to 20 minutes per frame, I think this could be done in around 40 days of constant rendering on one machine. So to break this down further, I already have one i7 quad core mac at home which will do the majority of these batch renders. Luckily the guys at work have offered a machine or two if they are not being used over the weekends to help finish the job, excellent news that may save my life.

LIGHT DRIVEN PARTICLE SIMULATION / V.02

April 8, 2010

In order to take the lighting rig a step further I needed to consider the inverse-square falloff of real life illumination when affecting the particles. With the help from a colleague at work we scripted a creation expression within the Per Particles attributes that defined the scale of each particle based on the position of the light and it’s falloff intensity. As the moving light approaches the particles they balloon in size and change colour, only returning to their original state when outside of the falloff radius.

While this currently all appears rather abstract, the intention is to use a simulation like this within my film to illustrate the transformative effects of photoreception in biological organisms. These tests are effectively helping further develop the physical interaction of a light source with any given objects in my scene. I think the next phase will be for me to demonstrate how texture and geometry can be driven in a similar way to the particles shown here.

The expression below shows how the position and intensity of the light source (pointLightShape1) is controlling the particles (nParticleShape1) size (radiusPP) and their colour (rgbPP).

CORNFORD & CROSS / LEAF RENDERS

March 28, 2010

Last month I was asked by Cornford & Cross to help visualize one of their proposed projects. They were interested in commissioning a digital artist to accurately model and render a dying English Oak tree in the court yard of Milton Keynes Shopping Centre, reproducing it in all it’s summer glory and displaying the billboard sized image within the shopping centre, mirroring the large advertising posters around the new and sterile complex.

Unfortunately the project never materialized but the preliminary renders of leaves I did proved good practice in simulating organic forms within Maya. As I am currently deep in the production phase of my film, it is interesting looking back and seeing how useful this exercise was in developing my knowledge of SSS (Sub-Surface-Scattering) shaders to a create realistic plant material.

PHOTOGRAPHIC EXPOSURE CALCULATOR / 1929-1930

March 24, 2010

While foraging through the debris of an East End market I found this wonderful photographic handbook from the late 1920’s published by Burroughs Wellcome & Co. The small document is filled with useful information designed to assist the photographer at every stage of his work. From essential facts about lenses to mixing chemicals and developing bromide paper, this book also comes with a diary and monthly light tables. At the back is the Exposure Calculator, a wheel that gives the photographer the correct exposure in seconds or fractions of a second depending on the type of shot they are taking (studio, distant landscapes, cloud cover…etc).

It’s fascinating to see how simply this book could predetermine depending on the time of year the suitable lighting conditions within which to take the perfect picture. Through understanding the principles of daylight the cinematographer could gauge very accurately what exposure would suite them best. Before the days of electronic lighting meters we relied so much on the clockwork cycles of natural light to provide this fundamental information for film and photography.

LIGHT DRIVEN PARTICLE SIMULATION / V.01

March 14, 2010

Having completed a rough storyboard for my final piece I’ve started to play around in Maya with different dynamic lighting setups. Because the premise of the work deals with the photobiological effect I am keen to create a lighting rig that could use its intensity to drive the animation of certain objects and simulations. The playblast below shows a point light that when turned on directly affects the turbulence of the particles. When the light is off the particles are static, but when illuminated they move quickly around the scene, the faster they move the longer their trial.

In the Hypergraph of Maya I connected a light source to the multiply/divide node which fed straight into the magnitude value of the turbulence field. For the time being this simply gives me a flexible and effective lighting rig that I can use to affect the dynamic properties of anything in my scene. However this is still faking the photoperiod effect in that the object is merely connected through the intensity value of the light source. To take this a step further I intend to follow up a more physically accurate network possibly using a surface luminance node to calculate the exact amount of light falling on a surface by using this value to drive the motion, scale, texture….etc.

PHOTOBIOLOGY

March 14, 2010

Photobiology is the scientific study of the interactions of light with living organisms. The field includes the study of photosynthesis, photomorphogenesis, visual processing, circadian rhythms, bioluminescence, and ultraviolet radiation effects. Rather than focusing on the effects of natural light I am more interested in the physiological effects of artificial light and how this interrupts the Photoperiod Effect (plant and animal response to length of day and night). During my research I have come across a number of journals on the internet that deal with this area of study. The Influence of Incandescent Light on Reproductive and Physiological Responses of Bovine Bulls as carried out by J.D. Roussel is an experiment in which a number of bulls were exposed to 14 hours of artificial light a day while the rest of the herd continued to graze under natural illumination. The results showed that an increase in exposure to light produced a greater reproductive response that Roussel put down to an increase in germ cell production within the animals. He found that in some way the thyroidal activity was altered which indirectly affected semen quality and other metabolic functions. By altering the natural circadian rhythm of day and night, biological and physiology changes occured.

Further Research includes;

Some Effects of The Photoperiod on Development of the Impatiens Balsamea – J. Perry Austin

Prepartum Photoperiod Effect on Milk Yield and Composition in Dairy Cows – Y. Aharoni, A. Brosh, and E. Ezrat

Effects of Artificial Ultraviolet Light Exposure on Reproductive Success of the Female Panther Chameleon (Furcifer pardalis) in Captivity – G. W. Ferguson, W. H. Gehrmann, T.C. Chen, E.S. Dierenfield, and M.F. Holick

Extraretinal Photoreception during the Gonadal Photorefractory Period in the Golden-crowned Sparrow
– Fred W. Turek (below)

Abstract:

Extraretinal photoreception is involved in the perception of light used to measure photoperiodic time during the initiation of gonadal growth in a number of birds. Evidence is presented which demonstrates that extraretinal photoreeeptors are also involved in measuring photoperiodic time during the gonadal photorefractory period in the golden- crowned sparrow (Fig. 3). Untreated sparrows were able to terminate the refractory condition while being exposed to long dim days (16DL:8D; DL–~0.2 lux). However, birds which had their head feathers clipped to allow more light to penetrate through to the brain were main- rained in the refractory state under the same lighting conditions. These results demonstrate that extraretinal photoreception is involved in the maintenance of photorefractoriness in birds.

It has been suggested that the eyes and extraretinal photoreceptors may both be involved in the initiation of gonadal growth in golden-crowned sparrows (Gwinner et al., 1971). This conclusion was based on the observation that a reduced rate of gonadal growth occurred in sparrows with shielded brains as compared to unshielded controls when both groups of birds were exposed to the same light treatment (i.e. 16L:8D; L=6 lux). The results presented here suggest that at a light intensity of 6 lux, light may have been reaching extraretinal photoreceptors even in birds with shielded brains. Therefore, the eyes may not be involved in testicular recrudescence in this species.

This level of research into the effects of prolonged artificial light is increasing dramatically within our current medical health care system as new developments reveal the dangers of disrupting cyclical photoperiodism. It is this biological approach to photoreception in living organisms that my film will attempt to question and explore.

http://www.photobiology.info/

UNITED VISUAL ARTISTS / DEUS

February 24, 2010

Continuing my research into artists who engage with the medium of light I remembered these photographs taken by UVA that help represent the compelling properties of artificial light on the surrounding natural environment. They document a number of experimental light installations in secluded areas of Britain, visualising a sharp contrast to the natural landscape around them and thus creating a sort of divine ephemeral space.

When living in the city one becomes accustom to the illumination of the streets and houses at night. This continual presence and necessity for light interests me; how this affects the human condition and the natural world is an area I am currently researching further.