Scannequin vs. Photofly

Exported Scannequin OBJ Opened with Rhino

As a follow-up to last week's mind-bendingly high quality scan of an owl pencil holder using Autodesk's Photofly photogrammetry software, I decided to bring out the Scannequin. The Scannequin (scanner + mannequin) is an anthropomorphic model with optically challenging features that the DAAP Rapid Prototyping Center (RPC) is currently using to evaluate the performance of various 3D scanners on the market.

Scannequin

Instead of moving around the object with my camera like I did last time, I placed the object onto a custom made rotary table that would lock into place every five degrees. The idea is that my camera would stay still on a tripod while the object spins at exact five degree increments.

Scannequin Feet on Custom Rotary Table

This turned out to be something of a mistake, as Photofly became confused when the background, lighting, and the turntable markings were not consistently located relative to the spinning model. (Disclaimer: The Scannequin was purposefully designed to be difficult to scan in order to find the scanning technology that would be the most versatile and adaptive to common scanning problems, so this is not necessarily a Photofly limitation - there would be problems no matter what when dealing with reflective surfaces.) The compiled model in Photofly was able to read the Scannequin's back which had brightly colored markings that made pixel matching easy, but the rest of the Scannequin exploded into a fractured mesh resembling liquid. In the Photofly screenshot below you can see where the camera location icons all begin to gather together in the same location, which corresponds with the error in the model.

Scannequin on Rotary Table - Photofly

So I tried again sans turntable by rolling my camera around the object on a heavy duty monopod with casters, taking photos about once every ten degrees in three concentric circles (angled from below, head on, and angled from above - lots of crouching and climbing up on stools). The model was more legible using this method (less liquidy explosion) but the fact of the matter remains that light reflections in a glossy surface are going to change relative to that surface regardless of whether the camera is moving or the object is spinning. In conclusion, scanners don't like reflective surfaces (so no scanning a T-1000).

Scannequin w/out Rotary Table - Photofly

Exported Scannequin OBJ Opened with Rhino

What I need to do at this point is to get some variation of developer spray, dulling spray, or "solvent removable penetrant" - it seems that their application in industry is to assist in the identification of fissures in metal parts, but they're often used in 3D scanning to turn reflective surfaces matte to enable them to be scanned. These are typically acetone-based sprays that (allegedly) wipe off easily with a dry cloth. I've gone ahead and ordered a can of Krylon Dulling Spray, but I've also heard great things about Magnaflux Spotcheck SKL-SP2. Wish me luck...

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Autodesk Photofly Test

Owl Pencil Holder

So what's all the fuss about photogrammetry? I decided to find out for myself, and to see if this method, which creates three dimensional geometry from photographs, would indeed be a scanner killer. Though there are many products out there, I decided to use Autodesk Labs' Project Photofly: Photo Scene Editor which is free to download and uses cloud processing power to generate your scan (they'll email you when it's ready if you run out of patience watching the progress bar.)

I started by setting an object, a plastic owl pencil holder (etsy?), on a stool. Autodesk's shooting guidelines video recommends that you photograph the object by encircling it and taking a picture once every five to ten degrees, so about forty to fifty photos per revolution. You can then proceed to do additional revolutions at various elevations to capture the underside and top of your piece being scanned. You can also take some closer detailed photos if you're looking for a higher resolution around a particular area, like the owl's face.

I captured the owl by rolling around it in an office chair and taking photos with a Nikon D50 in what felt like even five to ten degree increments, though as I get more serious with the scans I intend to fabricate a rotary table that will snap to every fifth degree with a pin captured by a stationary camera on a tripod. You can see a portion of my photo sequence in the image below.

Owl Photo Sequence

Upon launching Photofly I uploaded the images and waited for the cloud to process the data into a three dimensional mesh. Photofly returned an accurate low poly mesh with color information in around ten minutes. You can see from the image below that Photofly will also accurately locate your camera's position relative to the model and the sequence in which the photographs were taken - this allows you to make some edits if Photofly has initially processed your photos incorrectly.

Autodesk Photo Scene Editor

Once you're happy with the low poly model you can re-process it as a higher resolution mesh. For me, this took about an additional ten minutes before it returned my high-res mesh, the quality of which astounded me considering that this came from mere photographs. The native Photofly file format is extension 3DP so I exported the model as an OBJ (the other options are DWG, FBX, RZI, IPM, and LAS). This allowed me to pull the model into Rhino for mesh fixing.

Ghosted Mesh in Rhino

Rendered Mesh in Rhino

Ghosted Mesh Detail

Rendered Mesh Detail

I hope to find some time in the coming weeks to do a 3D print - either with one of our ZCorp powder printing machines or the MakerBot downstairs.

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New Materials Library

Early Prototype

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CNC-Patterned Aluminum Worktables

Offset Pattern Test Piece

Raster Pattern Machining

Half Faced, Half Patterned

Completed Raster Pattern

Cleaned Table in RPC

Offset Pattern on Komo

Offset Pattern Detail

Offset Pattern Detail

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Summer 2010 eBike Studio

"ONCYCLE

Designed for the savviest of people, the OnCycle is as effortless as it is practical. Its iconic silhouette makes it instantly recognizable, while its numerous features make it a practical investment for any young professional. Non-standard parts may seem unconventional, but this isn't a bike, it's an ONCYCLE."

_project brief from Team ONCYCLE (Mei Hsieh, Matt Gill, Alex Broerman, Aaron Kurosu, + Tony Cohen)

Prototyping at a larger scale than usual, and extremely excited to do so, Team ONCYCLE made extensive use of the Rapid Prototyping Center's facilities during the industrial design ebike studio. Coming into renewed popularity in the contemporary climate of a reduced economy and a stigmatized oil industry, electric bicycles feature motor-assisted pedaling powered by rechargable batteries. It is estimated that 300,000 ebikes will be sold in the US in 2010, with over a million being sold in Europe.

See also:


finished ebike

rhino fixturing model

inner race frame finish toolpath

pedal tactile pattern - 3d offset finishing toolpath

milled modulan foam frame

students testing fit during painting

students presenting during final critique

happy to be finished

detail - rear wheel

detail - handlebars


Another team of students envisioned ebike infrastructure, including bicycle storage and path networks, for the city of San Francsisco. Kudos to this team of industrial designers for stepping out of their comfort zone into the world of GIS. Who would have thought that Alias would be used for topographic modeling?

instructions for laser cutting

models of proposed bike storage and bike paths

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3D Scanning Demos

The RPC has been looking into purchasing a 3D scanner. More information coming soon...



















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Advanced Architecture Digital Fabrication Seminar

all installation photographs by David O'Connell (dvmoc@flickr)

What had started as an integration of basic Rhino instruction into the graduate architecture curriculum ended up, wonderfully, as an advanced architecture seminar in digital skills that investigated the positive feedback loop that occurs between NURBS modeling (curve-controlled surfaces) and CNC machining (curve-controlled toolpaths). Dan Korman, owner and manager of Over-The-Rhine's green general store Park + Vine, requested a window installation to advertise his selection of urban composting products. To construct the installation, students plugged custom birch components with a common rear face into a regular grid milled from glue-lam OSB, (made possible by our large VACU Press). The students followed a modeling strategy to create a landscape of decomposition, bringing to mind the holey space of worm-composting.

u+v-iso test from Komo demo

v-iso test from Komo demo

student artifact test

breaking off the OSB tongues prior to glue-lamming

starting block

mill position 1 - common rear faces

mill position 2 - custom front faces

aperture detail from front

partial installation

break

partial installation

aperture detail from behind

completed installation

artifact pattern detail

artifact embedded pattern detail

aperture shapes from rear

completed installation

completed installation

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Penny Drive Waterfall Installation

Nick Germann and I were asked to create an installation to mark the start of DAAP's contribution to an ambitious billion-penny penny drive here at the university. One simple idea drove the project: people are likely to give more pennies if the giving is fun.

CAM scene for collection box at base

CAM scene with simplified toolpath pattern

assembly in progress

assembly in progress

elbow detail

completed installation from cafe

completed installation from overhead gallery

arcade token clogging routed chute

lap joint detail

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More KOMO Aluminum Surface Pattern Tests

pattern toolpath from Rhino (arrows show direction)


pattern sample (stitch)

pattern sample (stitch) - detail

reflection in patterned aluminum

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PDx / Amerimold Expo 2010

Innovation in Execution

The RPC recently had a chance to exhibit its work at the PDx / Amerimold Expo 2010 at the Duke Energy Center in downtown Cincinnati. Along with Eureka Ranch and GE Aviation, the RPC exhibited in the "Innovation in Execution Area," which was the focal point of the show, promoting innovative and speculative uses of mold-making and other fabrication technologies. I've posted low-res images of our booth space and display graphics below.

Innovation in Execution Area

What We Use

The Rapid Prototyping Center

School of Architecture and Interior Design

School of Design - Product Design Track

School of Design - Transportation Design Track


The Wacom Cintiq 21 UX

Our contact at Wacom was good enough to lend us a few Cintiq 21UX models to show off our students at the expo. Graphics and digital slides of RPC student work were supplemented with the students themselves doing their homework publicly - whether they were modeling in Alias and Rhino or sketching on the Cintiq in SketchBook Pro or Photoshop - in order to foster a discussion of process in addition to product. It was also a great reminder that digitally-fabricated prototypes still start with a pencil, or at least a stylus.

Autodesk Sketchbook Pro 2010 on Wacom Cintiq 21UX

Adobe Photoshop CS4 on Wacom Cintiq 21UX

Adobe Photoshop CS4 on Wacom Cintiq 21UX


New Technology

In addition to showing our technology off, the expo was a great opportunity to learn about emerging technologies that we haven't yet gotten our hands on. The Exact Metrology booth was showing the Romer Absolute Arm, which is the first digitizing arm to "know" the location of its joints so that it never needs to be homed. This 6-axis arm comes with a software plug-in that allows for real time digital model adjustment with the digitizer. This is currently available for SolidWorks and will soon come to other platforms like Rhino.

Romer Absolute Arm

The Objet booth was showing, in addition to their other great additive machines, the Connex500. This is the first 3d printer to be able to simultaneously jet multiple materials (with different colors and densities) within the same part. These materials can even be blended with one another in different ratios to create custom composites.

Objet Connex500 Polymaterial 3d Printer

The SensAble booth was showing their Phantom Omni Haptic Device. This device makes it possible to use a stylus on a multi-axis arm to touch and edit digital models through tactile feedback using the FreeForm Modeling system.

SensAble Phantom Omni Haptic Device

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CAM for the CAM

A while ago we had the opportunity to use CAM (computer-aided manufacturing) for the CAM (Cincinnati Art Museum). Under the direction of Aaron Betsky, reknowned architecture critic and director of the museum, Sean Cottengim, an adjunct for SAID teaching in the first year studios, designed a set of screen walls for the exhibit "Roaring Tigers, Leaping Carp: Decoding the Symbolic Language of Chinese Animal Painting."

Typical CAD Layout
pieces being routed
finished pieces on Komo bed
panel mockup
panel mockup detail
Sean assembling pieces at museum
partially assembled panel
final installation

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Laser Samples Board Expanded

I finally got around to adding a few new melamine boards to the laser samples area, though it's still not nearly enough room to show off all the research and interesting projects that come through our laser machines. If there's anything you'd like to see added, whether it's cutting new materials or testing out unorthodox (but fire-safe) ideas, feel free to contact me. We're currently interested in expanding our palette of fabrics/textiles.

Be on the lookout in the coming weeks for instructions regarding our new capability to raster etch with the BEAM Dynamics laser cutter, (in the past raster etching has only been available on the Epilog machine). For more information on laser materials, including important information on testing new materials, click here.






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New Surfaced-Finished Aluminum Worktable

We've recently resurfaced the worktable we use to finish photopolymer resin 3D prints. We wanted to do something special, so we went with surface-finished aluminum. The tool followed the V-direction isocurves of the model surface to create the pattern. By finishing the aluminum at a depth of just under 0.002" with a 3/4" tip-radius bit we were able to get a visible pattern without leftover tactile artifacts such as cusps or burrs.

detail of surface finish

isocurve pattern extracted from Rhino surface

CAM programming in Delcam PowerMILL


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Machine Trends: Autumn '09

It's been another busy quarter in the Rapid Prototyping Center. The following are some quick shots I took of trends that I noticed in RPC-aided student projects during their respective critiques. Later I'll post more in-depth information on a few select projects.


CNC Plywood Laminates (Feature Set Machining)

The following two projects from the School of Architecture and Interior Design's "Funny Furniture" (23INTD414) seminar stacked parts from flat-stock materials to create three-dimensional form. Instead of relying upon 3D models, students submitted 2D CAD models from Rhino and AutoCAD to the RPC. Feature sets were then used within the CNC CAM program to extrude the 2D information, allowing the tool to respond to the depth of the material being cut.


Peter McBride


Peter McBride


Maureen Capretta


Maureen Capretta


Laser-Etched Graphics (BEAM Laser Vector Fill)

The following project, also from the "Funny Furniture" seminar, was created through a vector fill operation in the BEAM Dynamics laser cutter. The student used Illustrator's Live Trace tool to convert the original image of broken glass from a raster image to a vector boundary, which was then programmed for fill power and density in the laser CAM program.


Alexander Spencer


Large-Scale Topographic Models

The KOMO router was used by several students to machine large-scale topographic models. Using ArcMap, the students extracted local contour data from CAGIS. These contour polylines were edited in AutoCAD and then used to make NURBS planes in Rhino, at which point they were ready to be submitted for CAM programming. Flat-finishing (horizontals and verts) was the name of the game. The students would go on to lasercut their buildings, which fit into corresponding pockets that they had milled in the topography.


Christopher Retzler (topo L-R: Newport KY, Licking River, Covington KY, Ohio River, Cincinnati OH)


Third-Year Architecture Studio (topo: Mt. Adams neighborhood of Cincinnati)

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Featured Faculty Work: Future Retrieval

Katie Parker and Guy Michael Davis, adjuncts in DAAP's fine arts program, ply their porcelain trade under the name Future Retrieval. They've collaborated with Exact Metrology and the Rapid Prototyping Center to create porcelain casts from 3D inkjet powder printed parts, which in turn come from 3D digitized hand-crafted objects and, well, taxidermied animals. Future Retrieval are currently showing their work through December 19th in the exhibit "License to Illuminate" at Country Club.


*.STL file of digitized rat


Alliteration alert: Partially and presumably painstakingly painted porcelain rat with "historical patterns from illuminated manuscripts" (image by Future Retrieval).


*.STL file of digitized dog head


The digital model is shelled to reduce cost and pierced at the bottom to allow uncured powder to escape after the print. Notice how the interior surface is low-poly to keep the file size down.


printed dog head


porcelain dogs (image by Future Retrieval)


*.STL file of digitized flower


The final print (approximately one foot square) compared to a smaller test print and, finally, the original hand-made piece from Dresden. The ridges in the large piece are actually the blown-up fingerprints from the artisan who crafted the original flower.


*.STL file of digitized wolf head


Porcelain lamp of wolf heads. In a potentially ironic move, some of the finished heads have been chiseled by hand to mimic a low-poly mesh (image by Future Retrieval).

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Laser Cutting Carbon Nanotube Electrodes

We've recently received some scanning electron microscope (SEM) images from Department of Chemistry graduate student Amos Doepke. Amos used the RPC's Epilog laser cutter to cut carbon nanotube electrodes to a specified length. The laser cutter was used because any manual means of cutting would have been so destructive as to retard the nanotube's conductivity. The image captions have been provided by Amos.

nanotube bundle

"The first image shows the nanotube bundle (millions of nanotubes) protruding from the conductive epoxy. There is a ring around the nanotube bundle near the tip. This ring is from the polystyrene insulation, it was burnt away near [the cut]."

nanotube bundle - detail

"The second image is a close up of the first [image] showing that the laser cut very cleanly..."

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Laser Relief Print Quicktime


The Rapid Prototyping Center was approached by DAAP Fine Arts professor Don Kelley to develop a laser curriculum for relief printmaking.

To achieve this, digital images were prepped in Photoshop and Illustrator for the BEAM Dynamics Laser Cutter, which then etched away material from the students' wood blocks in the manner of a traditional knife or chisel. The material that had been etched away would print white, whereas the remainder of the block would pick up the ink and print black.

Paths taken from Illustrator were used as boundary objects for vector filling hatches in the BEAM's software. Such filling operations move much more quickly and effectively than if the student were to program the hatches themselves within their respective CAD packages.

The movie above shows the laser performing a fill operation. See the link below for the complete tutorial.

BEAM Relief Print Tutorial



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The RPC Tweets!



Follow the RPC's Twitter posts for important notices about machine availability, queue length, exemplary work, and more.

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Featured Student Work: Summer '09

Featured Student Work will be posted at the end of each academic quarter. Its purpose is to highlight select student projects made possible by the Rapid Prototyping Center.


Gary Clarke / Speed Form

  • Discipline: Industrial Design (Transportation Track)
  • Software: Alias StudioTools, ZPrint
  • Technology: 3D Printing
  • Machine: ZCorp 510 Powder Printer
The Speed Form is an introductory transportation design project. The smooth, undetailed form allows the student to focus on crafting a seamless surface model that will machine efficiently in the 3d printers.



The student begins by modeling the Speed Form from NURBS surfaces in Alias StudioTools. Ruled surfaces are stitched together to avoid gaps in the surface model, which would cause the 3d print to fail.



The student then breaks the Speed Form up into multiple components. This helps the model to fit within the print bed of the 3d printer, and may also help to keep the cost of the print down, which is primarily based upon the height of the build. Breaking a shelled model into components can also be useful as a means to provide escape outlets for loose powder trapped within the printed shell.


These snapshots of the 3d printer's build layers show the thickness of the shelled model. Watertight surfaces define layer profiles within which the 3d printhead lays binder (shown here in black).


The 3d print is finished, but there is some post-processing that needs to be done before the model is ready. Sanding, epoxying, painting, and clear-coating are common methods for finishing a 3d powder print. The student has modeled bosses and pockets into the Speed Form for a quick and reliable final assembly.


This rotisserie-style rack has a hand crank at the top, allowing the student to rotate the model while painting. Touching the model as little as possible is important for the integrity of the paint job, especially with the Speed Forms, which often use highly-reflective finishes to mimic automobile design and emphasize surface quality.


The model is finished with a metal flake spray paint and professionally photographed in the DAAP Photo Lab. It's good practice to photograph as soon as possible after the paint job is finished. Metal flake paints in particular are prone to, well, flaking.



Ed Mangum / Koi Lounge

  • Discipline: Industrial Design (Product Track)
  • Software: Alias StudioTools, Delcam PowerMILL, Adobe Illustrator, Delcam PowerShape, LaserLink
  • Technology: CNC Milling, Laser Machining, a little bit of sewing
  • Machine: KOMO CNC Router, BEAM Dynamics Laser Cutter

"Koi Lounge is a tiled seating system that enhances the mood and atmosphere in a variety of public spaces. The felt seat seemingly emerges from the ground..."

The base form of Koi Lounge is constructed from fourteen layers of CNC-milled MDF slabs. Pins will be inserted into the modeled holes to reference the slabs to one another in the construction of the final form.

The base form is made up of three smaller forms. The middle form will eventually support the water bladder while the top form will be used as a steam mold for the felt veneer.

The slabs are cut from nine 8 x 9' sheets of MDF. Some slab layers are split in half to efficiently fit the machined parts onto the sheets, which in turn must be a suitable size for the KOMO bed.

The laser machining of the felt pattern consists of five over-sized sheets. The excess felt was rolled and bunched to the sides of the 48 x 48" laser bed. Three of the sheets required more than one position in order to etch the full pattern (which often exceeded the maximum cutting area) resulting in a total of eight laser setups for the felt.




sheet 1/5



sheet 2/5 position 1



sheet 2/5 position 2



sheet 3/5 position 1



sheet 3/5 position 2



sheet 4/5 position 1



sheet 4/5 position 2



sheet 5/5



Ed looks on at the final critique of the Koi Lounge. Shown above is the RF-welded PVC plastic bladder sitting atop the CNC-milled MDF base. Apparently you can't help but touch it.




Chengguo Zhao / Triathlon Training Facility

  • Discipline: Architecture
  • Software: Autodesk Maya, ZPrint
  • Technology: 3D Printing
  • Machine: ZCorp 510 Powder Printer

"Design a triathlon training center using design principles and methods involving a structure of three; a primary, secondary, and tertiary system for planning and enclosure design."

_excerpt from course description

from parti to tripartite spatial system
floor plans
slab, structure, and skin
These diagrams explain the evolution from parti to spatial volume to a tripartite system of slab, structure, and skin. These elements were visualized in Maya. Maya's polygonal modeling tools are a common method for breaking up a digital form into poly faces that can be edited individually or uniformly as selection sets, which begins to address construction strategies and allows the student to quickly create a wide range of building apertures.



The student's structural mesh. Polygonal modeling, when done with care, is also an excellent way to ensure that you are always modeling a watertight surface, which lends itself to a successful 3d print. Furthermore, Maya's attribute history allows the student to quickly modulate the thickness of the mesh shell without remodeling anything.



The student's printed mesh. Due to the relative fragility of the structural form, the student modeled a base in order to provide a handhold that wouldn't crush the model as well as a contact surface between the printed form and the paper topography below.



The student's skin mesh showing a variety of apertures achieved through Maya polygonal modeling.



To finish his 3d print, the student applied a silver spray paint that is sufficiently matte to show the polygonal edges of the digital model, which mimic panelized construction methods in architecture.

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