Scanning turntable digitizes objects as 3D models

This turntable can automatically digitize objects for use in 3D rendering software like Blender3D. [James Dalby] built it using a high-quality DSLR, and some bits and pieces out of his junk box. The turntable itself is a Lazy Susan turned on its head. The base for the spinning model is normally what sits on the table, but this way it gives him an area to rest the model, and the larger portion acts as a mounting surface for the drive mechanism.

He used the stepper motor from a scanner, as well as the belt and tension hardware from a printer to motorize the platform. This is driven by a transistor array (a ULN2003 chip) connected to an Arduino. The microcontroller also controls the shutter of the camera. We’ve included his code after the break; you’ll find his demo video embedded there as well.

The concept is the same as other turntable builds we’ve seen, But [James] takes the post-processing one step further. Rather than just make a rotating gif he is using Autodesk 123D to create a digital model from the set of images.

Continue reading “Scanning turntable digitizes objects as 3D models”

3D whiteboard without the whiteboard

This one is so simple, and works so well, we’d call it a hoax if April 1st hadn’t already passed us by. But we’re confident that what [William Myers] and [Guo Jie Chin] came up with exists, and we want one of our own. The project is a method of drawing in 3 dimensions using ultrasonic sensors.

They call it 3D Paint, and that’s fitting since the software interface is much like the original MS Paint. It can show you the movements of the stylus in three axes, but it can also assemble an anaglyph — the kind of 3D that uses those red and blue filter glasses — so that the artists can see the 3D rendering as it is being drawn.

The hardware depends on a trio of sensors and a stylus that are all controlled by an ATmega644. That’s it for hardware (to be fair, there are a few trivial amplifier circuits too), making this an incredibly affordable setup. The real work, and the reason the input is so smooth and accurate, comes in the MATLAB code which does the trilateration. If you like to get elbow deep in the math the article linked above has plenty to interest you. If you’re more of a visual learner just skip down after the break for the demo video.

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View Gerber files in 3d in your browser

[Mark] wrote in, eager to show off this new tool he’s created to view your gerber files in 3d. He also wrote an instructible to go along with it, to help you figure out how to use the tool. Being an in-browser tool also means you can shoot it to your friends for a quick 3d review as well. Some of you may not feel that the 3d view is that helpful to the process, but we think that this is a welcomed feature that just might get some use around here.

[Mark] points out that it is still being actively developed, so please shoot him bugs via the form on the website if you should encounter any.

V-Synch detector lets you use 3D shutter glasses on Linux systems

This circuit is how [John Tsiombikas] makes his cheap 3D shutter glasses work with a Linux machine. It’s not that they were incompatible with Linux. The issue is that only certain video cards have the stereo port necessary to drive the head-mounted hardware.

Shutter glasses block light from one eye at a time, so that different renderings can be shown to create the stereoscopic effect. Since stimulating the muscles in the eye doesn’t actually work, you need to find a way to drive the glasses in perfect time with the video signal. His circuit watches for the V-Sync signal, then uses it to toggle the shutter glasses. Since the hardware has no way of knowing whether the left or right frame is being generated, he included the toggle switch as a user-controlled adjustment. If the 3D isn’t coming together, you’re probably viewing the frames with the wrong eye and need to flip the switch.

There’s really no way to show the effect without trying out the hardware in person. But [John] reports that it works like a charm when used with the OpenGL stereo wrapper.

Build your own line laser for 3D scanning


[Valentin] wanted to experiment with 3D scanning some objects he had around the house, but says he didn’t want to buy a line laser for the project since they are pretty expensive. Fortunately, he had some random components sitting in his parts bin, and he was able to build his own line laser without spending a ton of money.

His tutorial actually covers two different methods of building line lasers, both of which use parts that you likely have on hand already.

His first build involves gluing a small square mirror to a flat platform, which he then mounted on a salvaged DC motor. Once the motor starts spinning, the cheap laser pointer he has aimed at the mirror draws a perfect line across whatever medium he is scanning.

His second line laser uses parts donated from an old hard drive that he no longer used. He removed the drive’s read head from the chassis and mounted a small mirror on the actuator arm before firing up his laser. With the laser aimed at the mirror, he applied an unspecified AC current to the motor, which caused it to oscillate and draw a line similar to his first setup.

While they might not be professionally-built scanning lasers, [Valentin’s] efforts produced some decent images, as you can see on his site.

Continue reading to see a short video of his DC motor laser line in action.

Continue reading “Build your own line laser for 3D scanning”

Microsoft shows off their transparent 3D desktop prototype

We think most would agree that the Microsoft Kinect is a miraculous piece of hardware. The affordable availability of a high-quality depth camera was the genesis of a myriad of hacks. And now it seems that type of data is making an intriguing 3D display possible.

What you see above is a 3D monitor concept that Microsoft developed. It starts off looking much like a tablet PC, but the screen can be lifted up toward the user whose arms reach around it to get at the keyboard underneath. There is as depth camera that can see the hands and fingers of the user to allow manipulation of the virtual environment. But that’s only part of the problem. You need some way to align the user’s eyes with what’s on the screen. They seem to have solved that problem too, using another depth camera to track the location of the user’s head. This means that you can lean from one side to the other and the perspective of the virtual 3D desktop will change to preserve the apparent distance of each object.

Don’t miss the show-and-tell video after the break. As long as there’s only one viewer this looks like a perfect non-glasses alternative to current 3D hardware offerings. Continue reading “Microsoft shows off their transparent 3D desktop prototype”

Make any photo 3D using The Gimp

Put your face close to the screen and cross your eyes until the two images above become one. You may need to adjust the tilt of your chin to make it happen, but when they come together you’ll see [John Lennon] pop out in 3D. This was made using a 3D rendering script for The Gimp.

The process is not entirely automatic, but it won’t take too long to mask off the outlines for different depth layers. The script makes three different layers from the image. One of them is a color-coded depth map that uses a custom color palatte to choose distance for each item. If you paint the background dark blue it will be processed at the furthest distance from the viewer’s cross-eyed perspective, yellow is the nearest.

[Don] mentions a parallel output and a cross-eyed output in his write up. We understand the cross-eyed version, but are just guessing that the parallel version would be used in a stereoscopic viewer that puts a partition between the two images so that each eye sees a different frame. You know, like a View-Master.