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Sculpting Shadows

By Albert Thrower – albertthrower@gmail.com

OVERVIEW

In this project, I created three-dimensional sculptural artworks derived from the shadows cast by found objects.

BACKGROUND

I began creating 3D prints through unusual processes in 2018, when I used oils to essentially paint a 3D shape. For me, this was a fun way to dip my toes into 3D modeling and printing using the skills I already had (painting) rather than those I didn’t (3D modeling). I was very happy with the output of this process, which I think lent the 3D model a unique texture–it wore its paint-ishness proudly, with bumpy ridges and ravines born from brushstrokes. There was an organic quality that I didn’t often see in 3D models fabricated digitally. I immediately began thinking of other unconventional ways to arrive at 3D shapes, and cyanotype solar prints quickly rose to the top of processes I was excited to try.

SHADOWS AND DIMENSIONS

My initial goal with this project was simply to test my theory that I could create interesting sculpture through the manipulation of shadow. However, a presentation by Josh Michaels on my first night at Dinacon got me thinking more about shadows and what they represent in the relationships between dimensions. Josh showed Carl Sagan’s famous explanation of the 4th dimension from Cosmos.

Sagan illustrates how a shadow is an imperfect two-dimensional projection of a three-dimensional object. I wondered–if all we had was a two-dimensional shadow, what could we theorize about the three-dimensional object? If we were the inhabitants of Plato’s cave, watching the shadows of the world play on the wall, what objects could we fashion from the clay at our feet to reflect what we imagined was out there? What stories could we ascribe to these imperfectly theorized forms? When early humans saw the the night sky, we couldn’t see the three-dimensional reality of space and stars–we saw a two-dimensional tapestry from which we theorized three-dimensional creatures and heroes and villains and conflicts and passions. We looked up and saw our reflection. What does a rambutan shadow become without the knowledge of a rambutan, with instead the innate human impulse to project meaning and personality and story upon that which we cannot fully comprehend? That’s what I became excited to explore with this project. But first, how to make the darn things?

THE PROCESS

For those who want to try this at home, I have written a detailed How To about the process on my website. But the basic workflow I followed was this:

STEP 1: MAKE A SOLAR PRINT OF SOME INTERESTING OBJECTS

  • Exposing a solar print with rambutan husk shadows.
  • Washing the solar print after exposure.

The areas that are more shaded by our objects stay white, and the areas that the sun hits become a darker blue. Note that the solar print that results from three-dimensional objects like these rambutans have some midtones that follow their curves, because though they cast hard shadows, some light leaks in from the sides. The closer an object gets to the solar paper, the more light it blocks. This effect will make a big difference in how these prints translate to 3D models.

A rambutan print soon after exposure and washing.

STEP 2: USE THE SOLAR PRINT AS A DEPTH MAP TO CREATE A 3D MODEL

For those unfamiliar with depth maps, essentially the software* interprets the luminance data of a pixel (how bright it is) as depth information. Depth maps can be used for a variety of applications, but in this case the lightest parts of the image become the more raised parts of the 3D model, and the darker parts become the more recessed parts. For our solar prints, what this means is that the areas where our objects touched the paper (or at least came very close to it) will be white and therefore raised, the areas that weren’t shaded at all by our objects will become dark and therefore recessed, and the areas that are shaded but which some light can leak into around the objects will by our mid-tones, and will lead to some smooth graded surfaces in the 3D model.

 *I used Photoshop for this process, but if you have a suggestion for a free program that can do the same, please contact me. I’d like for this process to be accessible to as many people as possible.

Below, you can play around with some 3D models alongside the solar prints from which they were derived. Compare them to see how subtle variations in the luminance information from the 2D image has been translated into depth information to create a 3D model.

In the below solar print, I laid a spiralled vine over the top of the other objects being printed. Because it was raised off the paper by the other objects, light leaked in and created a fainter shadow, resulting in a cool background swirl in the 3D model. Manipulating objects’ distance from the paper proved to be an effective method to create foreground/background separation in the final 3D model.

The objects to be solar printed, before I laid the spiralled vine on the other objects and exposed the paper.

Another variable that I manipulated to create different levels in the 3D model was exposure time. The fainter leaves coming into the below solar print weren’t any father from the solar paper than the other leaves, but I placed them after the solar print had been exposed for a couple of minutes. This made their resulting imprint fainter/darker, and therefore more backgrounded than the leaves that had been there for the duration of the exposure. You can also see where some of the leaves moved during the exposure, as they have a faint double image that creates a cool “step” effect in the 3D model. You might also notice that the 3D model has more of a texture than the others on this page. That comes from the paper itself, which is a different brand than I used for the others. The paper texture creates slight variations in luminance which translate as bump patterns in the model. You run into a similar effect with camera grain–even at high ISOs, the slight variation in luminance from pixel to pixel can look very pronounced when translated to 3D. I discuss how to manage this in the How To page for this process.

One more neat thing about this one is that I made the print on top of a folder that had a barcode on it, and that reflected back enough light through the paper that it came out in the solar print and the 3D model (in the bottom right). After I noticed this I started exposing my prints on a solid black surface.

The below solar print was made later in the day–notice the long shadows. It was also in the partial shade of a tree, so the bottom left corner of the print darkens. If you turn the 3D model to its side you’ll see how that light falloff results in a thinning of the model. I also took this photo before the print had fully developed the deep blue it would eventually reach, and that lack of contrast results in the faint seedpod in the bottom left not differentiating itself much from the background in the 3D model. I found that these prints could take a couple days to fully “develop.”

STEP 3: 3D PRINT THE MODEL

The 3D models that Photoshop spits out through this process can sometimes have structural problems that a 3D printer doesn’t quite know how to deal with. I explain these problems and how to fix them in greater detail in the How To page for this process.

STEP 4: PAINT THE 3D PRINT

Now we get back to my musings about Plato’s cave. My goal in the painting stage was to find meaning and story in this extrapolation of 3D forms from a 2D projection. As of this writing I have only finished one of these paintings, pictured below.

  • Priming the PLA print with an absorbent ground.
  • Death of the Patriarchs, 2019.

FUTURE DIRECTIONS

– Carve the models out of wood with a CNC milling machine to reduce plastic use. I actually used PLA, which is derived from corn starch and is biodegradable under industrial conditions, but is still not ideal. This will also allow me to go BIGGER with the sculptural pieces, which wouldn’t be impossible with 3D printing but would require some tedious labor to bond together multiple prints. 

– Move away from right angles! Though I was attempting to make some unusual “canvasses” for painting, I ended up replicating the rectangular characteristics of traditional painting surfaces, which seems particularly egregious when modeling irregular organic shapes. Creating non-rectangular pieces will require making prints that capture the entire perimeter of the objects’ shadows without cutting them off. I can then tell the software to “drop out” the negative space. I have already made some prints that I think will work well for this, I’ll update this page once I 3D model them.

– Build a custom solar printing rig to allow for more flexibility in constructing interesting prints. A limitation of this process was that I wanted to create complex and delicate compositions of shadows but it was hard to not disturb the three-dimensional objects when moving between the composition and exposure phases. My general process in this iteration of the project was to arrange the objects on a piece of plexiglass on top of an opaque card on top of the solar print. This allowed me time to experiment with arrangements of the objects, but the process of pulling the opaque card out to reveal the print inevitably disrupted the objects and then I would have to scramble to reset them as best I could. Arranging the objects inside wasn’t a good option because I couldn’t see the shadows the sun would cast, which were essentially the medium I was working with. The rig I imagine to solve this would be a frame with a transparent top and a sliding opaque board which could be pulled out to reveal the solar paper below without disrupting the arrangement of objects on top. 

– Solar print living creatures! I attempted this at Dinacon with a centipede, as did Andy Quitmeyer with some leafcutter ants. It’s difficult to do! One reason is that living creatures tend to move around and solar prints require a few minutes of exposure time. I was thinking something like a frog that might hop around a bit, stay still, hop around some more would work, but still you would need to have some kind of clear container that would contain the animal without casting its own shadow. I also thought maybe a busy leafcutter ant “highway” would have dense enough traffic to leave behind ghostly ant trails, but Andy discovered that the ants are not keen to walk over solar paper laid in their path. A custom rig like the one discussed above could maybe be used–place the rig in their path, allow them time to acclimate to its presence and walk over it, then expose the paper underneath them without disturbing their work.

– Projection map visuals onto the 3D prints! These pieces were created to be static paintings, but they could also make for cool three-dimensional animated pieces. Bigger would be better for this purpose.

My project table at the end-of-Dinacon showcase.
This kiddo immediately began matching the objects I had on display to their respective solar prints!
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The Future Within – Grace Grothaus

Grace Grothaus
THE FUTURE WITHIN: A digital seed archive and interactive sculpture series exploring
threatened plant biodiversity in the americas


“First and above all an explanation must do justice to the thing that is to be explained, must not devaluate it, interpret it away, belittle it, or garble it, in order to make it easier to understand. The question is not “At what view of the phenomenon must we arrive in order to explain it in accordance with one or another philosophy?” but precisely the reverse: “What philosophy is requisite if we are to live up to the subject, be on a level with it?” The question is not how the phenomenon must be turned, twisted, narrowed, crippled so as to be explicable, at all costs, upon principles that we have once and for all resolved not to go beyond. The question is: “To what point must we enlarge our thought so that it shall be in proportion to the phenomenon…” – Schelling


“The future is not in front of us, for it is here already in the shape of a germ (seed).” “What is not with us will not be, even in the future.” Čapek


A result of cumulative anthropogenic activity, global mass extinction is currently in progress, a phenomenon which many refer to as the sixth extinction. I am attempting to grappling with this phenomenon as an artist and to live up to the enormity of the subject. In Schelling’s expostulation I begin to see the beginnings of a course of action. To enlarge my thought to be in proportion to the phenomenon, I must immerse myself in it, far beyond the four walls of my studio. In so doing I deepen my knowledge base and in turn the efficacy of my artistic practice upon return to studio. We see more clearly by recording what we see firsthand. With this understanding and via the support of the Digital Naturalism Conference, the Tinker Foundation, and the University of California San Diego, I conducted field research July-September 2019 in forests across the Americas: South, Central and North. Specifcally in the Panamanian canal zone tropical moist broadleaf forest (“rainforest”), Brazilian Cerrado, Mata Atlântica, and the North Atlantic forest of the Blue Ridge Parkway. Especially in Panama and in Brazil, these biodiversity hotspots are home to a great number of endemic species, some of which have not yet even been discovered. Especially in Brazil they are also threatened. According to UNESCO, the Cerrado, the second largest biome in South America, less than 30% of the natural vegetation remains and continues to shrink and the original Mata Atlântica has experienced 85% deforestation. These are places of irreplaceable biodiversity. For example the Cerrado is the most biodiverse savannah in the world. Yet devastating losses continue. It is highly probable that many endemic species have already faced extinction before being recognized by the scientific community and the broader world at large, and even more are at risk today.

These past few months during my hikes in these forests and grassland, I sought out seeds, seedpods, and fruiting bodies of as many different plant species as possible and from them created 3D digital models. In this way I digitally collected 60 unique specimens in Panama during Dinacon, another 152 in South America, and 45 thus far from North America where I am working now. All together this represents 257 unique species. The digital models of them are comprised of a staggering 26,000+ images taken of the specimens during the photogrammetry process. In addition, I have nearly seven thousand photographs, video, and audio recordings, numerous field notes and
sketches. Via field guides and discussion with generous researchers at Inhotim Botanical Gardens, the Smithsonian Tropical Research Institute, and the University of California San Diego I have been identifying the species of my specimens and learning about them.

In particular, discussion with two of STRI’s post-doctoral research fellows about their
research into seed dormancy in tropical forests was eye-opening. Seeds in more temperate forests are known for their lengthy fertile dormancy and it is not unknown to find specimens to lie dormant but still viable for even tens of thousands of years, yet in tropical forests the duration is much shorter, ending after only a few years and stretching into a decade or two max, species and soil conditions dependent. Reasons are not wholly clear, yet in both locations the seeds are not impaired by the soil, rather they actually need the soil microbes for the possibility of germination. Like the wildfires of the Cerrado, tropical soil is able to abrade the seed surface enough for germination. Seeds possess a chalazal area or plug, a round location on the surface that must break away, in order for the plant embryo inside to emerge and grow. In discussion of mechanisms by which future climate change may affect the species they study, the researchers explained that it is not only microbial/soil abrasion in the tropics that are sufficient to break physical dormancy in seeds, but also fluctuations in
the soil temperature. Surface soil temperature is dependent on ambient air temperature and so in a much warmer future, the viability window of opportunity for these seeds may well shorten. This is but one of the numerous concrete mechanisms by which species in this biome face future loss and potential extinction, and one I was previously wholly unaware of.

It can be cognitively difficult to focus on the slow growing and near silent plants around us. We have a tendency to look at plants as part of another and separate “natural world,” perhaps even a backdrop upon which we and other animals live out our lives, but this mindset is a fallacy. Plants are the keystone upon which all mammals rely.
The pace of plant growth is so slow compared to human movement, it lends toward the human impression of the plant world as constant, reliable backdrop, yet everything is growing constantly and all that I observed was constantly in flux. I’m grateful for the extended time dedicated to careful observation this field research provided, and reminded of Heraclitus’s truism that you can only step into the same river
once. In the same way that it is difficult to focus attention for the length of time requisite to really witness a plant grow, climate crisis is similarly difficult to observe, and yet with both the cumulative changes are unmistakable.

The photogrammetry process enables me to digitally collect only and leave no trace behind me – the real specimens in their home environments where they belong. I am developing a growing digital record, but just a tiny fraction of the species diversity that was all around me. Many more species were not in seed during the time of my visit and many more eluded my discovery, having already dispersed to the wind, soil, or animal digestion. The seed specimens I did collect vary greatly in size from a paper thin ~1/64 of an inch thick to 18 3/8 inch long. I was thorough in my collection but still others were too small, lacking any dimension of length and therefore impossible to capture using the set-up available to me. Perhaps farther in the future with other support I’ll be able to model via micro MRI imaging. In the near term I am now in the process of turning these digital models into sculptures. printing them into physical objects and embedding my motion-sensitive electronics inside that will enable the finished sculptures to murmur sounds into our ears. If a seashell held to the ear presents to our imagination sounds of the ocean though in fact amplifying the rush of our own blood circulating, then perhaps these seed sculpture sound compositions, composed from field recordings and whispered text, will amplify our hopes and fears about our planetary future to a level that we cannot ignore.