3D Scanning of Large Objects with Clusters of Complex Parts
When faced with digitally capturing large objects with multiple areas of high detail, even scanning professionals can feel a sense of uneasiness on how to best proceed. This could be an vehicle customizer with just half an afternoon to scan the interior and exterior of a Lamborghini for designing custom, perfectly-fitting components and modifications or an aerospace engineer assigned to scan an Airbus A380 cockpit and transform it into a VR-ready, sub-millimeter-accurate 3D model in mere days.
The clock keeps ticking as the engineer sits there wondering how he’s going to precisely capture and process the entire instrument panel, its eight displays, plus all the switches, buttons, and joysticks. Not to mention the seats and the entire architecture of the flight deck.
What may at first appear to be a straightforward scanning task can quickly turn into a multi-phase project that stretches out into weeks.
These types of scenarios inspired Artec Ambassador ShareMind’s Pietro Meloni to create a streamlined workflow to painlessly capture and transform multifaceted, ‘larger than human-sized’ objects into astoundingly-accurate 3D models in a fraction of the time.
As a benchmark object, Meloni chose a 3-meter-long kayak, since it features both large expanses of relatively simple geometry, along with multiple components with high detail, soft materials, and even recessed, difficult-to-reach parts.
He selected the Artec Leo as his primary scanner for the project. Leo is a revolutionary, portable 3D scanner that’s entirely wireless, with onboard processing and a rear touchscreen for monitoring the scan in real time. Ideal for capturing medium-sized objects in high-resolution color 3D (up to .1 mm accuracy), Leo makes it easy for anyone from beginner to pro’s to simply push the button and start scanning.
With Leo in hand, Meloni captured the entire kayak along with its nearly 60 parts in 5 minutes. He then processed the scans in Artec Studio software in 13 minutes. But he wasn’t 100% satisfied with the results. His goal was to find the best way possible to create a 3D model so exquisite that it could withstand expert inspection. Meloni soon understood that the more complex aspects of the kayak would benefit from the use of another scanner, the Artec Space Spider.
A metrologically-accurate (up to .05 mm) handheld 3D scanner, Space Spider excels at reverse engineering and quality control, with its ability to capture complex geometries and thin surfaces, and is highly suitable for scanning small-sized areas.
In Meloni’s words, “Just as you wouldn’t bring a scalpel to the jungle, or a machete to the operating room, each scanner is excellent at what it’s designed for. And Artec Studio 15 makes it incredibly easy to combine scans from multiple Artec scanners so you can create phenomenal 3D models in minutes.” He continued, “Many customers mistakenly imagine that one 3D scanner can perfectly capture everything from a delicate emerald ring all the way up to a circus tent.”
The second aspect of the project that needed to be addressed was how to deal with soft, flexible elements, such as the kayak’s cordage. These thin ropes are stretched across various sections of the fiberglass watercraft. When the kayak is moved, to capture the underside, for example, this cordage changes position, even ever so slightly. This results in double exposures in the scans, which are time-consuming to deal with via conventional methods.
What immediately came to mind is the possibility of using ZBrush to model these soft elements. Having experience with the software, Meloni decided that, “After all, there are many examples of materials and components with similar properties on objects that need scanning, whether they’re shoelaces or shoulder straps on a purse, or countless others…so if there’s an easier, faster way to model them and integrate them into a high-resolution 3D scan, I’m all for it.”
The final issue was how to scan several small components located in the cramped space of the kayak’s interior. Because of the short distances available between these and other objects, accessing them at every necessary angle of capture wasn’t possible. For example, the fishing rod holder, snugly recessed in the center of the kayak. That’s when Meloni decided to disassemble these parts and scan them separately.
This proved to be highly successful. It took just a handful of minutes to dismount all the parts. He then scanned each object using Space Spider and Artec Turntable, which are perfectly synchronized together, so in case the scanner ever loses tracking, Turntable rotates back a few degrees and waits till tracking is regained, then commences turning again.
Once scanned, Meloni smoothly merged each of these separate objects with the kayak directly in Artec Studio. “The process is actually very simple. It was straightforward to process each scan and combine it with the kayak. The results made it seem as if each part was right there all along. You can do this with scans from any Artec 3D scanner, from Micro to Ray, and it’s so easy to do that even a beginner can learn how in just a few minutes.”
For a few of the soft parts, such as the handles, Meloni decided to create a few simple 3D-printed supports, so these elements would be captured in exactly the same positions they held on the kayak.
Meloni explained his Artec Studio scan processing workflow: “Using Artec Studio 15, I aligned the scans without difficulty. Then I used Global Registration, waterproof Sharp Fusion, Fast Mesh Simplification, and Texturing. This is the workflow I followed for each element of the project, starting with the hull, and then for each separate part.”
He continued, “Artec Studio 15 greatly simplified the process for me with its Groups feature. While capturing the kayak, my Leo scans were automatically funneled into one folder, and then when I moved on to scan with Space Spider, for the small parts, all of those were grouped into their own separate folders. When you’re dealing with so many scans, having this kind of automatic organization makes a dramatic difference.”
“I need to add that when it came to scanning and processing the small components, I used the same steps as I did for the kayak’s hull, but with the Space Spider (using Artec Turntable) scans, during the scanning I had Automatic Base Removal turned on, and then during processing I also used the Outlier Removal filter.”
With all the scans completed and integrated together, it was time to focus on the cordage. The ZBrush modeling went perfectly, and within minutes, Meloni had modeled each of these once-elusive soft elements directly upon the kayak model itself.
“Because these elements serve more of a decorative function, they were ideal for such rapid 3D modeling, but if we had needed to capture their exact dimensions, for reverse engineering or quality control, for example, then we would’ve needed to use Space Spider to obtain far more accurate measurements of the cordage and other parts,” Meloni said.
In terms of bringing in multiple 3D scanners and additional tools to achieve better results, Meloni confirmed the success of this novel approach. It greatly reduced the total processing time needed, and the final 3D model was ready days earlier than expected. He encourages users to try new things.
“Yes, at first it does add a bit of extra time and complexity to your workflow, when you incorporate more than one scanner and software solution. But if you want to confidently take on projects with large objects that have numerous sections of high detail, you need to prepare for this, for when the time comes.”
Meloni went on, “And when you reach the end of such projects, hours or even days ahead of time, you’ll know that you’ve made the right choice. This makes perfect sense, how we need to experiment and create our own effective workflows.”
“If I use only my car to go to work every morning, what happens when one day there’s a huge traffic jam, with cars backed up across the city? Better then to also know how to use a bicycle or public transportation.”
For more information: www.artec3d.com
