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n9 3D Fashion Video

n9 Productions got in touch with me and a few other designers displaying prints at 3DEA, and a quick collaboration produced this great video. I was at the shoot to ensure good fitting of the work. After snapping on different sized connectors, the design fit the model very well.

Director/DP: Mark Ledzian
Editor/VFX: Tamino Castro
Executive Producer: Katie Daley
Producer: Chris Antonelli
Hair/Makeup: Rachel Bensimon
Art Director: Kemper Johnson

Models: Gabrielle Blevins and Mari Agory, Major Model Management

Music: Monosurround – Hello World

Featuring: Cocktail Parasol Hat – Heidi Lee / H E I D I L E E COUTURE
N12 Bikini – Mary Huang / Continuum Fashion
Morphogenesis Shoe – Pauline van Dongen
Seed of Life Corset – Aaron Trocola / ThreeForm/Forty West Designs)
Flow Dining Chair – Dirk van der Kooij

Picked up by Fabbaloo, FashioningTech, TheCreatorsProject, AdaFruit. Also big in Japan.

Presentations at MakeIt NYC

Explaining how Amandacera and I developed our printed corset.

The MakeIt NYC meetup group started by Jonathan Hirschman has grown to 350 members, and consistently fills the venue to capacity. The group normally features individuals and small businesses who want to share their creation or product, or sometimes representatives of companies that provide some useful tool or service for DIY projects. Last night I gave a presentation about my wearable designs and how I make them. This meetings theme was- you guessed it- 3d printing. I mostly tuned my talk to discuss the accessible photogramettry technology available to help people capture 3D shapes (roughly) for use in their 3d-printed projects.

Demonstrating the flexibility of printed products

We also heard from Shapeways, Solidoodle and from the New York City Economic Development Corporation (NYC EDC) who, along with Mayor Bloomberg, has taken a great interest in the culture shift toward Making. During Maker Faire last fall, the week was officially deemed “Maker Week”, and a number of projects have popped up to support themovement. In 2013, leadership has started to again recognize the value of individuals in contributing to our economy. There are hundreds of examples of very small companies creating jobs, successful products, and generally a lot of return on any investment. NYC EDC got together with Challenge Post, along with sponsors like Shapeways, Adafruit, and Honeybee robotics to create an interesting maker-themed competition called “New York’s Next Top Maker“, which ask competitors to submit the products they’re working on, and funds six selected finalists. The award of of $4,000 budget for finalist and $11,000 for the winner is certainly shoe-string when it’s comes to product development, so I don’t think we’ll be seeing any advanced electronics or other complications, but there are still a lot of possibilities for small projects. I imagine it has not escaped the attention of the organizers that a small consumer product, light on electronics, is a perfect candidate for prototyping and short-run production using 3D printing equipment also made in New York.

“everything, everything, everything…”

Voxels vs. Polygons

Can the use of voxels instead of polygons expand the possibilities for 3D printing? Yes! Here I will explain why, and show an example.

The Mandelbulb

The widespread adoption of volumetric representations can provide many benefits for additive manufacturing, both in the design stages and for production. In this post I will give some examples to demonstrate the practical value of using voxels over the polygon meshes that have become the standard way of storing and showing three dimensional objects.

Having worked as a specialist in 3D visualization tasked with preparing data for viewing on 3D displays, and with many years of 3D design and modeling experience, I have had the opportunity to face many challenges working with large data sets. Hitting limits of memory and processing power again and again, I have come up with a well-formed set of strategies for working with 3D data, and one of the most important lessons is that some data structures are more appropriate for different situations, depending on the nature of the information.

Generating Test Data

I have generated a sample dataset from a mathematical object known as the Mandelbulb fractal. This object has a large amount of surface detail. While the actual fractal surface is infinite, here a volumetric rendering has been made, creating a cube of 8.6 billion binary (black or white) voxels that measures 2048 voxels on a side. I processed that data to smooth out the noise and down-sampled it to a 512 cubed set, which contains a more manageable 134 million voxels. This set is 8-bit greyscale, and so the memory footprint is 131 Megabytes. I then used the Marching Cubes algorithm to generate a triangle mesh that approximates the shape. The resulting mesh has about 7 million polygons, and it’s size depends on the format. Typically, meshes in memory use about 12 bytes per vertex, and the number of vertices is about half the number of faces, which themselves occupy a a few bytes, so for our example we will approximate the memory usage at around 120MB, roughly the same as the voxel version.

A slice of the Mandelbulb

Comparing The Results

The memory footprint for our test datasets are well matched in size between the voxel and polygon versions, and the object is not an unrealistic example of a form that one would desire to print. The object is actually topologically simple in that it does not have any holes. While it has many tiny details, we are only concerned with details that are at a scale that can be printed. For the sake of this example, we are going to make the assumption that our object has voxels that are 0.1mm in size, corresponding to an object roughly 2 inches wide. I also created compressed versions of the data, since that is a common method of preparing files for transmission, and it gives a more accurate estimate of the files “entropy”; it reduces the redundancy to give us insight into how efficient the representation can be. Here are the files sizes for the different versions:

Original 2048 cubed binary set: 1,073,741,824 bytes (1GB)

2048 cubed PNG sequence (compressed): 70,616,000 bytes (69MB)

Processed 512 cubed greyscale set: 134,217,728 bytes (131MB)

Processed 512 cubed greyscale set (compressed): 9,779,180 bytes (10MB)

Processed 512 cubed greyscale PNG sequence (compressed): 21,970,559 bytes (22MB)

PLY isosurface mesh: 7 million polygons, 132,070,054 bytes (132MB)

PLY isosurface mesh: 7 million polygons (compressed), 50,810,994 bytes (50MB)

STL isosurface mesh (internal voids and small shells removed): 327,767,084 bytes (320MB)

STL isosurface mesh (internal voids and small shells removed, compressed): 136,552,091 bytes (133MB)

STL isosurface mesh (from 256 cube, polygon reduced): 700k polygons, 34,717,484 bytes (33MB)

I have provided links to the compressed data on Thingiverse for your examination. Taking a look at the space used on disk, the benefit is obvious. The RAW data is 131MB, the STL is 320MB. After compression the difference is even more dramatic. The STL is down to 135MB, but the RAW data is only 10MB! It is also important to remember that the RAW data still contains much more information. The isosurface mesh is only a two-dimensional membrane representing one value, while the volume data is greyscale and contains 256 discrete values, which can generate membranes at any value. The data essentially contains an extra “dimension”, which in mathematical terms is not insignificant and has important real-world implications for 3D printing.

How is this useful?

There are two important ways that the application of 3D printing is especially well matched to volumetric representation. First, it is very common to use lattice structures in additive manufacturing because detail is often essentially free, and is sometimes even beneficial to the efficiency of the production process. These structures can make an object so complicated that it becomes difficult to work with. While this is sometimes manageable with polygons, the solid model representation usually used in product design (boundary representation, a.k.a B-Rep) is much more unwieldy, and generating dense internal lattices is simply not practical using software like Solidworks and other CAD applications. Since the reproducible detail in proportion to object sizes being produced by today’s printers can be represented as voxels while remaining within a memory footprint that is workable with today’s computers, it is possible to generate and interact with these complicated models in a volumetric form.

The second characteristic has to do with material representation. The voxel data could easily correspond to a lookup table referring to hundreds of materials. Currently, if you want to take advantage of Objets multi-material printing, you must provide a separate STL mesh for each material combination. If you desire a smooth transition from hard to soft material for example, you will have to dissect your model into many complicated non-planar volumetric segments, a near-impossible feat for all but the simplest forms. Those forms would then be converted into polygons, and extremely small facets must be used to ensure continuity of the material.

Multi-material example

Let us imagine we want to print our fractal object using Objet’s multimaterial printing. we want to modify the surface finish by creating a “skin” of soft material over a harder structure. In this case, the volume version of the object would remain unchanged, but the polygonal version not only doubles, but triples in size because the outside skin must have an inside and an outside. The model size in STL format is now about a Gigabyte in size, and has more than 20 million polygons. The voxel data, however, is still 10Mb zipped, and can fit in video memory to be displayed at interactive rates (modern GPU’s have 3D texturing capability)

How do we use it?

Much like the infrastructure we’ve established around combustion-engine vehicles instead of electric ones, we are now finding that a transition to the next technology is challenging. There are several software packages that can help work with this type of data, but the system is not yet mature, and there is no integration between the data types. For example, both Materialise and Netfabb have software for generating internal lattices, what Netfabb calls “Selective Space Structures”, but all of this software accepts only polygon meshes as both input and output, which takes away the potential benefit of volumetric representation. I have discussed with Alexander Oster, the CEO of Netfabb, the possibility of completely eliminating polygons from the 3D printing pipeline. I sent him some test data and he said he would look into supporting voxel-based input that would be converted directly to output usable by 3D printers. [Edit: July 19th, 2012 - I've just received more information on the "Volumetric Printing" feature in the new Netfabb 4.9.2 release. This feature refers to a method of calculating the feed rate of the filament based on it's volume rather than trial and error, for better control of material deposition. Slice import is not yet implemented (three weeks would have been a miraculous pace to get that done). Hopefully we'll see it in the next round.] Unfortunately, home printers use FDM technology, which means that a tool path (a drawing pattern for the extruder nozzle) will still have to be generated from the volume data. This limits the utility of the approach, though it will still have some advantages for multi-material printing. Volume input should still be adopted so the technology can mature. When a voxel-based printing technology is affordable for the home, the software to support it will be ready. The next step from here is integrating this functionality directly into the solid modeling applications so we can define volumetric material properties and structures while maintaining the fidelity of the solid model. The application that comes closest to this level of integration is Sensable’s FreeForm haptic modeling system. Unfortunately the user will be outputting only polygon meshes or B-Rep solids from this system, but, as they were just purchased by Geomagic I am sure we will be seeing some changes coming up.

There are other benefits of voxel representations related to manifoldness and hole-filling. I will relate these in further posts.

You can find the Mandelbulb on Thingiverse here.

Read more on the subject in my post on Engineering.com here:

engineering.com/3DPrinting/3DPrintingArticles/ArticleID/4523/2012-The-Beginning-of-the-End-for-Polygons.aspx

Aero Table In Progress

I’m making a table from the vertical stabilizer (tail fin) of a Beech Model 18, the “Twin Beech”.  It has a really great shape to it and is nicely aged from sitting in a aircraft bone-yard for decades. Others have made furniture from airplane parts, but they are often smoothed with body-filler and repainted to perfection. I am thoroughly buffing it with a polishing compound, but I will not be doing any sanding or filling, and will leave the finish as raw aluminum. The tiny scratches and dents give it character. This piece has been aloft for thousands of hours over thousands of miles, and it has traveled a long way before it came to me, so I find it appropriate to acknowledge it’s long history rather than conceal it.

I’ve carefully scanned and measured it to create a matching glass top and wooden base. I’m really enjoying this project!

Digital English Muffin

A fully prepared 3D scan (Left), and raw scan data (Right)

This is a good demonstration of why models are repaired prior to 3D printing. Have you ever wondered what happens when you put a model with lots of errors, like raw scan data, into a 3D printer? The model on the left was a very difficult model to prepare for printing because of all the occlusions (a.k.a nooks and crannies) in the English Muffin that blocked the scan. The model on the right is not manifold or closed. Many parts are floating and there are huge holes. The result was that the infilling algorithm didn’t know when to quit, and ended up shooting voxel rays around the build chamber, impaling nearby models and contaminating the powder with bits of junk. I have affectionately dubbed it the “Death Star Muffin”.

Morning Star Heading To RAPID 2011

“The Morning Star is an incarnation of Danger and Beauty”

The upcoming RAPID 2011 conference in Minneapolis will feature many great examples of 3D printed artwork. This year I am fortunate enough to have one of my pieces displayed in the exhibition gallery. The Morning Star is made with a combination of 3D-printed stainless steel and CNC machined wood. I have spent a lot of time perfecting the model over the past year, and this past month I have been putting the finishing touches on the final piece. These images show the wooden handle being made. The final display for the Morning Star will be presented next week.

Morning Star Handle2 MorningStar_Handle4
MorningStar_Handle2 MorningStar_Crate

I could not find a CNC lathe locally, so I built the handle from five radial segments on a standard 3-axis CNC. The segments were laid out flat for cutting, then trimmed to the correct angles with a jointer. The glued segments were compressed onto the pentagon-shaped core with tightly wound rope.  A special crate was designed to securely house the Morning Star during it’s voyage.