Kenneth Zapata is a Designer at Fat Pencil Studio
In the past few years, we have been using laser scan data from other experts we work with or from law enforcement agencies (see here). This data has proven helpful in the creation of 3d models, offering an exceptional point of reference compared with aerial photographs, Google Earth, street view imagery, and scene photos. When correctly captured, it represents a highly accurate way of getting rich data from a scene without spending time measuring everything.
In 2020, the introduction of LiDAR sensors in devices like the iPhone 12 Pro and iPad Pro (4th-gen) opened up possibilities for architects, designers, video game developers, animators, and creators alike. Among the consumer-oriented apps, Polycam stands out as a favored choice. While other apps like Recon-3D, Dot3D, Canvas, SiteScape, Scaniverse, and 3D Scanner App exist, my personal experience with Polycam is the most user-friendly option for scanning objects, spaces, rooms, and capturing 360° panoramas.
But don't worry... we're definitely keeping our eye on what's out there without being tied to a single app.
via Polycam
In short, LiDAR and photogrammetry are both techniques used to gather data about the environment, but each do it in different ways. LiDAR, which stands for Light Detection and Ranging, uses invisible laser light to directly measure distances, while photogrammetry constructs 3d models from a large portion of photographs. LiDAR scans generate a point cloud while photogrammetry generates 3d meshes and textures.
With this exercise, I wanted to show what kind of data Polycam produces and how it can be used in our workflow. I'll try not to go too in-depth as this is by no means, a scientific approach but more to test out possibilities.
Benson Bubbler
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Photogrammetry via iPhone+app
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LiDAR mode exported as a point cloud
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Photogrammetry via multiple DSLR photos
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Photogrammetry via iPhone+app
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LiDAR mode exported as a point cloud
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Photogrammetry via multiple DSLR photos
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Photogrammetry via iPhone+app
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LiDAR mode exported as a point cloud
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Photogrammetry via multiple DSLR photos
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Photogrammetry via iPhone+app
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LiDAR mode exported as a point cloud
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Photogrammetry via multiple DSLR photos
If you've ever walked around Downtown Portland you'll find these Benson Bubblers everywhere. Although I do not drink from them myself, I appreciate how well maintained they are and love seeing them around town. You could find them all here on this map provided by the Portland Water Bureau.
'Allow Me' statue at Pioneer Courthouse Square
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Photogrammetry via iPhone+app
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Photogrammetry via iPhone+app
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Photogrammetry via iPhone+app
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Photogrammetry via iPhone+app
Now that fall is upon us, this is a great place to stay dry during the relentless Portland rain. Apparently, this statue, located in Portland's "Living Room", is one of seven!
BIKETOWN Bike
Those electric bikes that have been heaven sent when I miss the bus, Biketown ridership has been surging the Portland area. Question is... is it pronounced it Biketown or Bike(y)town?
Burnside Bridge
Using one of our previous case studies, Burnside Bridge, I see how the scan fares against our SketchUp model. It's a strange melding of 3d/CAD perfection and an export of data-heavy geometry.
I would say that the Polycam export could be used as a great reference file to model from. But similar to Google Earth, the model looks particular great from far away but as you zoom-in you notice some disparities. This could be because the scan wasn't done the best, the technology is limited or there is too much data to capture and the program takes some shortcuts to "fill-in" the holes.
Little Free Blockbuster
The more you walk around the city, the more things you see that make you think "I must scan this!". I've always gravitated to Little Free Libraries (another scanning idea here), but this was a first! You can find this one here on NE Fremont Street.
Okay, so that stuff is pretty cool but what are other possibilities... We can quickly scan objects particular to a case, we can scan a space while creating a fairly accurate 3d model, we can take footage from a drone akin to Google Earth.
Like I stated before, this saves time when your time limited with time on the field or jobsite. We would still recommend bringing a measuring tape, level, and electronic laser distance measurer because the phone still struggles with low lighting conditions, reflective surfaces, vegetation, and large areas.
In addition to LiDAR and photogrammetry, there's also applications such as Luma AI, NVIDIA Instant NeRFs, and KIRI Engine that generate a NeRF (Neural Radiance Fields). Since the start of this article, the latest craze has been 3D gaussian splatting which supposedly renders faster, is more accurate, and has a higher fidelity than photogrammetry and NeRFs. Be sure to follow the blog for future experiments.