Asteroids and minor planets

Developing my ideas towards the larger 3d prints has been challenging and I’ve found myself frequently hitting the limits of my technical ability with 3d modelling software. With the course taking place on a weekly basis, the pressure mounted as we developed our projects towards our larger 3d models on the SLS 3d printer. Selective laser sintering (SLS) is an additive manufacturing (AM) technology that uses a laser to sinter powdered plastic material into a solid structure based on a 3D model and gives a much more robust and refined result than the Makerbot desktop printers.

The apparent simplicity of the models I have been making belie a certain complexity. I often appropriate existing imagery and transform them to make suggestive comments on the nature of knowledge. Asteroid Bennu, as the subject of the current scientific mission OSIRIS-REX, offered a location to question one of its mission objectives: that its chemical composition might contain answers to the origins of life in our Solar System. In response, I wanted to open its structure up, to make simple cuts or incisions that would allow us to go beyond the undulations of its data-captured surface: to consider these bodies as both objects of science and enigma.

After sharing some work-in-progress with the Field/s peer forum last month, I was reminded of Roger Caillois’ The Writing of Stones. The book part documents Caillios’ incredible collection of image-stones [1]: stones which have been cut open and polished to reveal improbable pictures. His poetic writings describe how such natural markings direct the imagination to a hidden language of nature and the cosmos:

They proclaim the circuits of planets or electrons around their invisible centres or nuclei; they are an image of the fundamental yet simple law of gravity that links physical bodies together at every level of the Universe. They are the rings of armillary spheres. with their zodiacs and ecliptics and equinoctical zones – bracelets for cosmographers or nuclear physicists. They reflect the phantom revolutions which, alike on a vast and microscopic scale, unflaggingly repeat the same pattern. This is the blueprint of nature itself; both hidden and revealed in a nodule of silica, making known the blazon of the universe, the constant figure that governs it in its entirety. –Roger Caillois, The Writing of Stones

Having an interest in the use of mirrors and reflections in scientific imaging technologies and how they allow us see beyond our own limits, I wanted to use it as a substitute to the cut and polished surfaces of agate or jasper. Mirrors are also magical and illusory objects found in folklore and fiction. By inserting the mirror within the asteroid’s crust, its sleek surface where we find ourselves. Nylon filled with pools of semi-silver. In halves and laid open, it returns our gaze in a paradoxical act of revelation and concealment.

In order to create this, the shell of the 3d asteroid needed to be filled, extruded inwards to create a wall, and then downwards to create a recess the exact thickness of the mirror. It’s important to make thinks to the exact scale you will be printing at, when you scale up or down wall thickness will also increase/decrease proportionally. It is difficult to make accurate measurements in Maya and the triangles of the inner wall ended up conflicting with the outer wall. This is made more difficult by the fact that Maya doesn’t really show you any issues with your mesh while you are working – I guess because it is primarily geared for 3d animation rather than modelling where such issues are not so crucial. It was only during the evening course sessions I was able to use Materialise Magics (with the help of the course tutor) to highlight and fix problems with my mesh such as intersecting and overlapping triangles. It would have been useful to access this software off-site while developing my project. The shape for the mirrored section was created by screen-grabbing the asteroid and then tracing and sizing it in Adobe Illustrator ready for laser cutting.

Extracting the 3d prints from the printer itself was a tactile experience, digging them out of the bed before proceeding to sieve and air-blast them to remove excess powder. In fact, one of the things I have taken away from the course is how preparing and printing the 3d file can be only part of the process – there are many other manual processes that can be performed afterwards such as colouring, sanding and casting.

So, the course is nearly over but this really feels like the beginning. Having the opportunity to attend this course has given me a grounding in the area so I can continue to experiment using other materials such as metals [2], colour staining and electroplating, as well as moulding and casting in other materials such as plaster or Jesmonite – or even ceramics. I’m excited to develop this towards a more resolved sculptural installation, hopefully to be exhibited later this year with the Field/s Forum.

Further updates will be posted here. Many thanks to course tutor Anatol Just for his patience and support!

1. Roger Caillois’ dream stone collection was donated to the Muséum National D’Historie Naturelle (MNHM) in Paris, where it can be viewed.
2. 3d print bureaus offering prints in a variety of different materials include i.materialise and Shapeways

The third and fourth weeks have largely been spent working in the CAD suite and looking more closely at creating objects in programmes such as Studio 3d Max. 3D Studio Max is part of the Autodesk suite of programmes (also comprising AutoCad, Maya, BIM and Inventor). Handily, Autodesk programmes can be downloaded with a free, 3-year educational license if you are part of an educational establishment.

Most of the programmes work across Mac and PC programmes, except, 3ds Max – this is unfortunate as I am a Mac owner and I had definitely found this interface easiest to work with so far. 3d modelling software seems to be more geared towards PCs and it’s seriously made me consider switching over. In any case, for now I have settled on Maya to edit the asteroid meshes.

There are a plethora of programmes out there which can be confusing – and coming to this first time, requires a bit of time to play around and work out what software works best for your needs/project. I have made a small list below with links.

3d Modeling Programmes

3ds Max 
Free 3 year educational license – PC only.
Powerful 3d modeling toolset. Animation. Easy to use interface. Standard part of all of Autodesk’s industry collections for Architecture, Engineering & Construction; Product Design & Manufacturing; and Media & Entertainment. Course recommendation.

Maya 
Free 3 year educational license – Mac/PC
Modeling with more features for animation. More complex interface.

Mudbox
Free 3 year educational license – Mac/PC
More intuitive interface/toolset for 3d modeling (as with Sculptris below). Better with higher resolution meshes. Not for animation.

Meshlab
Free – Mac/PC
Open source system for processing and editing 3D triangular meshes. Set of tools for editing, cleaning, healing, inspecting, rendering, texturing and converting meshes. More for inspecting and repairing mesh files ready for a 3d printer.

Sculptris 
Free – Mac/PC
Artistic/intuitive interface and tools for modeling. Easy to use with potential to progress to more complex operations.

Rhino
License required. 70 day free trial. Educational discount available – Mac/PC
CAD, CAM, rapid prototyping, 3D printing and reverse engineering software. Used in industries including architecture, industrial design, product design as well as for multimedia and graphics. Plugins required for exporting .obj and .stl file formats. Easy to learn.

Materialise Magics 
Trial on request
A 3D print suite that pitches itself as the software backbone for all businesses and industries that need professional 3D Printing. Allows you to convert files to STL, repair errors, edit your design and prepare your build platform. Course recommendation but not easily obtainable.

Blender
Free – Mac/PC
Professional, free and open-source 3D computer graphics software toolset used for creating animated films, visual effects, art, 3D printedmodels, interactive 3D applications and video games. More complex interface and tools for both modeling and animation such as phython coding. Tools such as soldify modifier allow you to easily make a model hollow inside. 3d Printing Toolbox Addon for analysing meshes to check printability.

I wanted to share a few images from the exhibition Meterorites: From Sky to Earth that I caught at the Grande Galerie de l’Évolution (Gallery of Evolution) in Paris, back in March and was a great source of research. The exhibition covered everything from the strange and incredible circumstances of their creation to their significance to past civilisations such as the Mayans who thought meteorites were the excrement of the Gods. It’s quite easy to see how these bronzed lumps of nickel and iron could be likened to space pooh.

The exhibition included over 350 meteorites from the Muséum collection and an immersive video experience that took the viewer on a journey from deep inside the molecular clouds where the solar system first formed through to the meteroite falling to Earth. The narrative explained the current understanding of the Solar System’s origins and how the history of these rocks is intrinsically bound to our own. There was also a poetic audio piece that adopted the point of view of the meteorite falling to Earth which I felt had similarities to some of my own written works. Interwoven with these were contemporary artworks, but the real stars were the meteorites of course!

The exhibition contained many historical accounts of meteorites falling to Earth, such as the picture above of the Leonid meteor storm as seen over North America on the night of November 12–13, 1833, painted by Edmund Weiß ( in Bilderatlas der Sternenwelt) through to more contemporary accounts of the more recent Chelyabinsk meteor than fell in Russia in 2013, injuring hundreds.

The exhibition concluded with a documentary film about meteorite hunters in the Atacama Desert who talked about the search for these precious stones as a poetic act.

This evening’s session was hugely exciting! We had been set a task to bring in a small model to try out on one of the Maker Bots, so we started off by loading one of our own files onto the machine. The Maker Bot (pictured below) is a desktop 3d printer that prints using ‘Fused Deposition Modeling’ or FDM for short. It uses an extruder, which is similar in principle to a hot glue gun. Plastic filament is fed in through the top, is melted, and finally “extruded” out of a small nozzle into the layers that build a 3D print.’ [1]

Anatol, the course tutor explained thoroughly how meshes need to be prepared for print and loaded our models into Materialise Magics, an STL editing programme that can help detect and fix errors in 3d meshes and also outputs models into slices/layers that can be understood by the printer.

The picture above shows asteroid Bennu printed at just w18 × h13 × d15 mm – that’s 0.085% of it’s actual size (if my maths is correct!). I was surprised by the amount of detail and undulation in the surface that is captured even at this scale. Here it is displayed on a mirror. Mirrors are a key material in my practice – I reference them as highly scientific instruments used in telescopes and crucial to space imaging. I was interested to find out these NASA are created by radar astronomy. Even though a mirror is not used in this particular technology there is a nice link with the use of reflections: ‘Radar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the reflections.’ [2]

While our models were printing we were introduced to stereo lithography and shown the 3d scanning facilities: another route for creating 3d files for printing. I will be attempting to scan a sculptural object over the next couple of weeks.

[1] Learn the basics of 3d printing, https://www.makerbot.com/learn/
[2] Radar Astronomy, https://en.wikipedia.org/wiki/Radar_astronomy

Today was a great start to the course. We were given a detailed tour of the 3d printing facilities at The Cass by course tutor, Anatol Just. We looked at the various machines – SLS (Selective Laser Sintering), Z Corp 3D printing, Envisiontec 3D printing and Makerbot 3D printers – and were shown samples of the materials they print with the types products they are capable of producing. The possibilities seem enormous. Anatol emphasised the link between material reality: it’s easy to get carried away with 3d modelling software and make something that looks very impressive on screen – but the laws of physics still need to apply if you want to print it!

Anatol had prepared a comprehensive introduction the history of digital manufacturing, explaining how it goes back to 1801 with the Jacquard Loom being the first machine to use punch cards to control the movements of a machine. This introduction also covered the .stl (Standard Tessellation Language) file – the most common format to work with in 3d printing (although some .obj and .3ds will also work). These files work with meshes made of triangles. The more triangles a mesh has, the higher its resolution.

Things are starting to make sense – it’s such a relief from spending hours looking at these files unguided. I’m excited to start thinking how I can apply this new knowledge and understanding to Asteroids and other minor planets.