Here’s a camera rig that makes it a snap to produce photorealistic 3D models of an object. It was put together rather inexpensively by an indie game company called Skull Theatre. They published a couple of posts which show off how the rig was built and how it’s used to capture the models.
They’re using 123D, a software suite which is quite popular for digitizing items. The rig has a center table where an object is placed, and a movable jig which holds three different cameras (or one camera for three rotations). You can see the masking tape on the floor which marks the location for each shot. These positions are mapped out in the software so that it has an easy time putting them all together. The shaft which connects the jig to the base is adjustable to accommodate large or small items.
One thing that we found interesting is the team’s technique for dealing with reflections. They use a matte spray to make those surfaces less reflective. This helps 123D do its job but also allows them to map reflective surface more accurately using the game engine.
[Ajeromin] was asked to build something cool for a museum exhibit. He took the challenge, and with his facial capture device, we feel he delivered. The writeup is very short, most of the story is in the annotated images. After deciding he was going to do facial capture and convert it to 3d, he had to start planning. There are many ways to do this, but usually the person having their face captured isn’t an excited child at a museum. The presented some unique challenges in that he knew he would have to capture all the images at once, and quickly too. To do this, he lit the entire rig very well to reduce the amount of noise in the pictures and wired all 6 cameras up to snap at the same moment. He even encapsulated the circuit in a glass jar just so the kids could see more of the parts.
The next logical step would be to attach this to a 3d printer and let people buy 3d printed models of their face. The quality is certainly good enough as he shows in one of the final images.
Great job [Ajeromin]
After futzing around with a cheap pico projector, a webcam and a little bit of software, [Jas Strong] built herself a 3d scanner.
In spite of the dozens of Kinect-based scanner projects, we’ve seen structured light 3d scanners before. This method of volumetric scanning projects a series of gradient images onto a subject. A camera captures images of the patterns of light and dark on the model, math happens, and 3d data is spit out of a computer.
[Jas] found a Microvision SHOWWX laser pico projector on Woot. The laser in the projector plays a large part in the quality of her 3d models – without a focus, [Jas] can get very accurate depth information up close. A Logitech webcam modified for a tighter focus handles the video capture responsibilities. The software side of things are a few of these structured light utilities that [Jas] melded into a single Processing sketch.
The results are pretty remarkable for a rig that uses woodworking clamps to hold everything together. [Jas]’ 3d model of her cat’s house looks very good. She’s got a few bugs to work out in her setup, but [Jas]
plans on releasing her work out into the wild very soon. We’ll update this post whenever that happens. made her code available here. The code requires the ControlP5 and PeasyCam libraries.
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!