Hackaday Links: October 27, 2013


[Kyle] came across a project which he thinks is “simply elegant”. If you don’t already have a PCB vice, here’s an easy way to build one of your own.

This one’s so good but alas it’s not a hack. Check out the slideshow tour at UC Boulder’s Fiske Planetarium. You get a really cool look at the hardware that makes the dome and projector such a great experience. [via Reddit]

Here’s a schematic and a couple of snapshots of [Trax's] CAN bus hacking rig. He plans on doing a tutorial but decided to share this link after reading the first part of our own CAN hacking series.

These strings of LEDs bump to the tunes. [Alex] is using GrooveShark as a frequency analyzer, then pushing commands via Node.js to the Arduino controlling the lights. It’s all planned for the back porch during his Halloween party.

We remember drilling holes in the 3.5″ floppy discs (we even made a wood jig for this) to double their capacity. A similar blast from the past was to punch a notch in the larger 5.25″ versions to make them double-sided.

If you’re trying to learn about FFT [Ronald] highly recommends this website. We didn’t do too much poking around because it’s kind of strange. But if you do get sucked in and have fun with it leave a comment to let others know it’s worth their attention.

We suppose that using 39 Raspberry Pi boards and their camera modules isn’t the worst way to build a huge 3D model capture rig. The results certainly are impressive. [Thanks Wouter]

3D scanning by calculating the focus of each pixel


We understand the concept [Jean] used to create a 3D scan of his face, but the particulars are a bit beyond our own experience. He is not using a dark room and laser line to capture slices which can be reassembled later. Nope, this approach uses pictures taken with several different focal lengths.

The idea is to process the photos using luminance. It looks at a pixel and it’s neighbors, subtracting the luminance and summing the absolute values to estimate how well that pixel is in focus. Apparently if you do this with the entire image, and a set of other images taken from the same vantage point with different focal lengths, you end up with a depth map of pixels.

What we find most interesting about this is the resulting pixels retain their original color values. So after removing the cruft you get a 3D scan that is still in full color.

If you want to learn more about laser-based 3D scanning check out this project.

[Thanks Luca]

Makerbot shows off 3D scanner


We’ve said our piece over Makerbot and their interpretation of what Open Source means, but the fact remains if you’re sourcing a 3D printer for a high school shop class or a hackerspace, you really can’t do much better than a Makerbot Replicator. Apparently Makerbot is looking to expand their 3D design and fabrication portfolio; they just announced an upcoming 3D scanner at SXSW. It’s called the Makerbot Digitizer, and it takes real, 3D objects and turns them into CAD files.

Since Makerbot and [Bre Pettis] didn’t give out much information about the 3D scanner they’re working on, the best information comes from Techcrunch. The Makerbot Digitizer uses two lasers to scan real objects and turns them into 3D CAD files. The hardware isn’t finalized, and the prototype is made of a few pieces of laser cut plywood. No details are available on how much the Digitizer will cost, when it will be available, or what its resolution is.

Of course 3D scanning of real objects to translate them into CAD files is nothing new for Hackaday readers. We’ve seen our fair share of desktop 3D scanners, including one that was built in a day out of junk. Even the Kickstarter crew has gotten into the action with a few desktop 3D scanners, some of which scan in full color.

3D scanner made in a day


The LVL1 Hackerspace held a hackathon back in June and this is one of the projects that was created in that 24-hour period. It’s a 3D scanner made from leftover parts. The image gives you an idea of the math used in the image processing. It shows the angular relations between the laser diode, the subject being scanned, and the webcam doing the scanning.

The webcam is of rather low quality and one way to quickly improve the output would be to replace it with a better one. But because the rules said they had to use only materials from the parts bin it worked out just fine. The other issue that came into play was the there were no LCD monitors available for use in the project. Because of that they decided to make the device controllable over the network. On the right you can see a power supply taped to the top of a car computer. It connects to the laser (pulled out of a barcode scanner which produces a line of red light) and the turntable. A Python script does all of the image processing, assembling each slice of the scan into both an animated GIF and an OBJ file.

[Thanks Nathan]

Very easy 3D scanning software with ReconstructMe

[Maxzillian] sent in a pretty amazing project he’s been beta testing called ReconstructMe. Even though this project is just the result of software developers getting bored at their job, there’s a lot of potential in the 3D scanning abilities of ReconstructMe.

ReconstructMe is a software interface that allows anyone with a Kinect (or other 3D depth camera) in front of a scene and generate a 3D object on a computer in an .STL or .OBJ file. There are countless applications of this technology, such as scanning objects to duplicate with a 3D printer, or importing yourself into a video game.

There are a few downsides to ReconstructMe: The only 3D sensors supported are the xBox 360 Kinect and the ASUS Xtion. The Kinect for Windows isn’t supported yet. Right now, ReconstructMe is limited to scanning objects that fit into a one-meter cube and can only operate from the command line, but it looks like the ReconstructMe team is working on supporting larger scans.

While it’s not quite ready for prime time, ReconstructMe could serve as the basis for a few amazing 3D scanner builds. Check out the video demos after the break.

[Read more...]

Kinect-based turntable 3D scanner looks very promising

We know that the appearance of the Kinect 3D camera hardware, and subsequent open source driver hacking conquest, is a game-changer that brings the real world into much closer contact with the virtual world. But it still amazes us when we see a concept like this turntable-based 3D object scanner that works so incredibly well.

The concept is extremely simple. A box made from foamboard rests atop a turntable. At its center is the object you wish to scan being well-lit by a small LED light source at each upper corner of the box. First up some code and capture data about the sides and top of the object as it spins. To put the shoe back together in the virtual world, he used a modified version of RGBDemo v0.6.0, a Kinect focused project written by Nicolas Burrus.

[A.J] says that the scan comes out pretty well after just one pass, but that’s not stopping him from setting his sights on making this work with three of four Kinects at once. Don’t forget to check out his video demonstration which is embedded after the break.

[Read more...]

DIY 3D gets a nod at SIGGRAPH


Among the courses at this year’s SIGGRAPH (an annual technical conference and showcase of the latest in computer graphics research) was an introduction to 3D scanning that covers all the bases: mathematical foundations, two different build-your-own hardware approaches, and how to process and render the resulting datasets. The presenters have assembled all the course materials on a top-notch web site featuring slide shows, complete source code, and an extensive round-up with links to both commercial and homebrew 3D scanning gear. The simplest of these methods requires nothing more than a webcam, halogen light source, and a stick!

SIGGRAPH and 3D scanning have been highlighted many times on Hack a Day, but we’re swelling with pride now seeing an academic venue give a favorable nod to the DIY hacking community (on their links page). Okay, so Hack a Day isn’t called out by name, but just wait’ll next year!

[Thanks Fahrzin]