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The pitfalls and potential of inexpensive 3D scanning solutions

Ars puts five home 3D scanning options to the ultimate test—scanning kids and clay cats.

The odd documentary, feature article, or typical marketing hype may make you think that today's 3D scanning can perfectly capture the real world, but that's only true with expensive, professional equipment (not to mention considerable editing and post-processing). Generally, current consumer versions of 3D scanners produce decidedly modest results.

Still, personal 3D scanning has made great strides in recent years. And though it continues to take a backseat (in market- and mind-share) to 3D printing, 3D scanning has grown into a technological revolution worth exploring all on its own. So let's look closer at two of the main personal 3D scanning categories available: software- or hardware-based solutions that work with equipment you may already have and hardware-based solutions that are mostly self-contained. As a bonus, we'll also look at services where you can view and store 3D models, as well as ways to turn your 3D models back into physical objects.

While it's impossible to provide an exhaustive look at the ever-growing number of 3D scanning products, this selection of solutions should provide a solid overview of what's currently possible and where this technology might be headed next.

The basics

3D scanning is broadly defined as using a combination of hardware and software to analyze a real-world object or environment, collect usable data on its shape and other attributes, and then convert it into a digital model. While professional 3D scanners can easily reach into the tens of thousands of dollars and beyond, the price for the hobbyist user generally ranges from free (if you already have a good smartphone, tablet, or other camera) to a few thousand dollars for more purpose-built solutions.

Whatever the price range, most 3D scanning solutions targeted at hobbyists are limited to capturing features no smaller than 2 to 10 millimeters, or about 0.08 to 0.4 inches. While this is good for capturing the general shape of an object, fine details get lost and either need to be manually recreated or done without. Of course, even if a virtual recreation is only approximate, there’s still an advantage in having a rough digital model. Once an object is digital, all kinds of possibilities for manipulation, usage, and 3D printing open up.

Most consumer-based 3D scanning solutions rely on one of five approaches: photogrammetry, structured light, laser triangulation, RGB-D, or Time-of-Flight (ToF) technology. Naturally, each type of technology has its own pluses and minuses. In general, photogrammetry is fastest with the lowest barrier to entry; structured light and laser triangulation often provide the highest resolution and detail; and RGB-D and ToF offer a good mix of high speed and low barrier to entry, albeit with limited resolution. For the solutions that require a computer, using a laptop is generally preferred over a desktop since it offers more mobility, which becomes important when looking for a good environment to scan within and needing to look at a screen to preview a capture.

We'll stick with Commercial Off-The-Shelf (COTS) products here. This batch of products typically excludes the more do-it-yourself RGB-D (depth sensor and camera) and ToF (determines the distance to an object by measuring how long its infrared beam takes to reflect back) solutions since they require a user to piece together their own setups. For instance, the RGB-D-based Microsoft Xbox Kinect 360 hardware needs to be paired with a USB and power supply adapter to work on Windows 7 or later computers with the powerful ReconstructMe software. Similarly, the ToF-based Microsoft Kinect for Xbox One sensor needs to be paired with the Kinect Adapter for Windows, and it utilizes Microsoft 3D Scan for Windows 8.1 or later.

Regardless of technology used, 3D scanning solutions struggle with reflective, shiny, or translucent objects. Objects with gently contoured surfaces with soft curves, varying or light color (white rubber spray or powder can be used on very dark objects to help with scanning), and matte finishes or objects that are opaque tend to scan the best. Lighting is also critical. You need a well-lit environment, period. Harsh, direct lighting will cause issues, so ambient light is best. Because of relatively slow capture rates on even the fastest technology, any type of movement from the target object also results in a failed scan.

Typically, once a 3D scan is acquired, there's more work to be done. Most initial scans have stray objects, holes, and other issues that need to be addressed. Once edited, the 3D scan can then be exported to a specific file format, including STL or OBJ for 3D printing. Once exported, further editing may be necessary. For this overview, we'll primarily limit edits to only correcting the most significant flaws using included or recommended software as part of the initial scanning process.

Photogrammetry solutions: Fuel3D Scanify

At its core, photogrammetry technology uses multiple photographs taken from different angles. The Fuel3D SCANIFY hardware, which works with its Fuel3D Studio software, represents this approach in our scanning survey.

The Fuel3D SCANIFY Handheld 3D Scanner System for Windows 7 or later, or Macintosh computers, is described as a handheld, point-and-shoot 3D scanner that captures objects in high-resolution shape and color in just a tenth of a second. Although the most expensive product in this roundup (priced at $1,490.00 when we tested it, now available on sale for $799), the SCANIFY has a distinctly premium feel with a high-tech look. Perhaps the best way to describe its design is that it’s reminiscent of the front of some futuristic race car concepts.

The package comes with the scanner, three tracking targets, USB data transfer cable, AC power adaptor, International AC adapter connectors, warranty card, quick start guide, and a Fuel3D lens cloth. I was also supplied with a Fuel3D padded carrying case and an extra pack of 10 SCANIFY scanner tracking targets.

The quick start guide directs you to first register and then download the required Fuel3D Studio software. The Starter edition of the software is free and provides basic scan processing and file export, as well as up to 15 cloud processing sessions a month. Advanced and Professional packages carry a monthly subscription fee and feature more cloud processing sessions, advanced scan processing and editing, and more file export options.

After installing the software, plug in the USB cable and AC adapter. If you have a Windows-powered tablet, you can alternately buy the SCANIFY Mobile Package Cables (for $12.99), a battery pack, and a 3D printable battery and tablet mount for a more portable solution. In testing, I used the standard configuration with the AC adapter.

A tracking target placed near or on the object you're scanning is a requirement. Without that, the scanner doesn't know what to focus on. Because of this requirement, you may need to place smaller objects on a box or platform where the scanner target can rest (or stick, since a target has adhesive). You can also 3D print either a handheld or free-standing target holder, which can be downloaded from Sketchfab, a popular free service to publish, share, and discover 3D content online and in VR.

Fuel3D indicates that the SCANIFY is best for scanning the human form, fabrics, stone and masonry, wood carvings, stone sculptures, and plants or trees. If you want to scan something larger than the product's field of view—which is approximately 12" high and 8.5" across, or 14.5" diagonal—you'll need to take and stitch together multiple scans. I limited target acquisition to single scans when testing.

Overall operation is simple. Once the SCANIFY is connected to its AC adapter and to your computer with its USB cable, you open up the Fuel3D Studio software and launch the viewfinder. Once the scanner and software find the target and indicate a Green status (meaning the object is at a perfect distance from the target), press both buttons on the SCANIFY to take a photo. You then accept or reject the captured image. Once accepted, the software starts processing the scan.

While scanning is as quick as taking a photo, it sometimes takes time for the hardware to find and lock onto the tracking target. You'll sometimes need to move forward and back to get in just the right position.

SCANIFY did a great job of capturing faces, including details other solutions missed. Inanimate objects were a bit hit or miss. My white clay cat test creation was mostly unsatisfactory, while a fabric rose proved a bit better, if dark. Unlike many of the other solutions in this roundup, objects with varying, instead of monochromatic, color are definitely recommended for optimal results here.

Although the speed and quality of the SCANIFY's captures are high, particularly when it comes to capturing relatively fine detail, I would have liked to have seen a more automated stitching process for easier creation of 360-degree models. The Fuel3D Studio software’s Stitch Tool, which allows you to join multiple 3D scans to create a complete, 360-degree 3D model, can be challenging. As it is, SCANIFY is most efficient for capturing a single angle of an object and generating the largest, highest resolution files of any solution presented in this roundup.

If the Fuel3D SCANIFY is a bit out of your price range, lower-cost photogrammetry-based solutions to consider are Trnio, Agisoft's PhotoScan, and AutoDesk's ReMake. Trnio is a free app for Apple iOS-based devices (recent iPhones and iPads) and is arguably the best current alternative to AutoDesk 123D, which, much to the chagrin of its fans, was officially shut down on March 31, 2017. Agisoft PhotoScan has a free 30-day trial, starts at $179, and runs on Windows, Mac OS X, and Linux (Debian/Ubuntu) computers. AutoDesk ReMake has a limited free version or a paid version that starts at $30 per month, and it runs on Windows 7 or later computers (the Macintosh version was retired).

Channel Ars Technica