There’s an App for That: 3D Scanning with a Smartphone
Trudi Sandmeier 00:00
Today on Save As:
Ye Hong 00:01
I was hoping that it can be beneficial for the protection of our built environment, either to have like collective memories, and also for those sites that are physically inaccessible or being endangered or being ignored.
Trudi Sandmeier 00:24
Welcome to SaveAs: NextGen Heritage Conservation, an award-winning podcast that glimpses the future of the field with graduate students at the University of Southern California. I’m Trudi Sandmeier.
Cindy Olnick 00:36
And I’m Cindy Olnick. So, Trudi.
Trudi Sandmeier 00:40
Yes, Cindy?
Cindy Olnick 00:42
I’m always excited about our episodes, this one because it addresses a relatively new dual degree that we have here at the Heritage Conservation Program with Building Science.
Trudi Sandmeier 00:55
Yeah, the fusion of heritage conservation and building technology is so interesting, and kind of a new thing for us, not in the field, but certainly in terms of this new degree program. So Ye Hong is the very first graduate.
Cindy Olnick 01:12
No way really?
Trudi Sandmeier 01:14|
The very first one.
Trudi Sandmeier 01:15
That’s awesome.
Cindy Olnick 01:16
Cutting edge.
Cindy Olnick 01:17
I mean, if you think about it, heritage conservation is all about how buildings age, right? So if we want to keep them standing, for all sorts of reasons that we also address on the podcast, we need to know how. I’m also excited because this episode once again, underscores the access to incredible study sites that we have here in Los Angeles because of our wealth and legacy of residential modernism, for everything from thesis research to independent projects, like our last episode on the Wilfandel Clubhouse, and every year as our faithful listeners know, instructor Peyton Hall’s class on materials conservation.
Trudi Sandmeier 01:56
So I think we should get to it. And here’s a little bit of my conversation with Ye Hong.
Trudi Sandmeier 02:05
I’m really excited to be here to talk with Ye Hong, about her journey here at USC. So Ye Hong, welcome, and why don’t you take a minute and introduce yourself?
Ye Hong 02:16
Hello everyone. I am Ye Hong. I graduated from USC in 2023. And I was doing my master of Heritage Conservation and master of Building Science dual degree when I was at USC. I grew up in China, Beijing. It’s a very historic city, and I grew up in historic neighborhoods.
Trudi Sandmeier 02:40
Tell me a little bit about your background before you came into graduate school. What did you study as an undergrad?
Ye Hong 02:46
I majored in fine arts and art history at UCLA. I mostly did painting, drawing, and printmaking. It was a fun experience. At that stage, I was trying to explore what I really want. And I feel like I did a good job because I realized that’s not the thing I want.
Trudi Sandmeier 03:06
Good work.
Ye Hong 03:07
Yeah, it works.
Trudi Sandmeier 03:08
Totally.
Ye Hong 03:09
And then that can become my starting point of rethinking what should I do after my bachelor degree. So then I realized I am talented at fine art creation, but it’s just like a hobby for me. It can’t be a career for me. And I’m thinking of what valuable things I can do for my own community. And then I look around because my family are in the construction field, they are in the industry, I’m thinking maybe architecture, but I don’t want to do design anymore. I am done with design. And I was lucky I graduated one semester right before the pandemic and got into USC right at the end of the pandemic.
Trudi Sandmeier 03:53
Right, okay. That was clever of you. Well, so we recently started the dual degree program with the Building Science program because we know how interrelated the two disciplines are. Building Science is really about the technical study of buildings, how they’re built, and how they perform. Can you talk a little bit about the kinds of things you learned about?
Ye Hong 04:16
Just looking into the history is not enough for myself, I also want to know what can we do in the future for those buildings. I was very interested in the sustainable development of buildings of either like existing buildings or that will be built in the future. In the Building Science department, they teach about engineering, structural building performance analysis, simulation about HVAC, and the wall performance window to wall wish ratio. That really opens a new door to me and bring me to a new world.
Trudi Sandmeier 04:56
Absolutely.
Ye Hong 04:57
I still remember when I was in the building simulation class, the professor asked us to pick a site to do our modeling. I pick the Reunion House, and everyone was just picking their home. I’m like, I’m gonna do this historic one.
Trudi Sandmeier 05:15
Okay, well, so the Reunion House is a pretty special place, and I think you successfully used it for several of your class projects. So Sian Winship, who is also a grad of our program, is on the board of the Neutra Institute that manages the Reunion House. And she was one of the folks who helped Ye Hong get access to the building to be able to do her thesis research, which is really fantastic. So we asked Sian to tell us a little bit about Reunion House.
Sian Winship 05:48
Reunion House was built in 1950. It was designed by Richard Neutra, and it was actually a speculative house that he designed for Arthur Johnson. It was called Reunion House because it was designed for three generations of a family — grandparents, parents, and grandkids to all come together periodically and socialize. So in 1963, when VDL House, Mr. Neutra’s studio and residence burned, he then moved to Reunion House. The house was later purchased by Dione. And then Dione sold it to Richard and Dione’s son, Dion Neutra, who was an architect in his father’s office. And Dion lived there until his passing in 2019.
Trudi Sandmeier 06:34
So, Ye Hong approached the Institute about using the site for her thesis. When she asked you this crazy question, what what were your thoughts?
Sian Winship 06:45
Well, the Institute is charged with using these buildings for educational purposes. So frankly, we were delighted that she was going to do something that was also a test of technology. Our mission really lies at the nexus of preserving the legacy of Richard Neutra, and promoting design that advances his ideas about bio-realism. So it was actually a perfect project for us.
Sian Winship 06:52
So turning back to Ye Hong, tell us about how you first found out about the Reunion House.
Ye Hong 07:24
I first got there because of Professor Peyton Hall’s class. We were using it as a case study for the entire class.
Trudi Sandmeier 07:34
Right. And we did a podcast episode on your work at the house.
Ye Hong 07:38
Yes.
Trudi Sandmeier 07:39
So there is an episode on the Reunion House that you all can go listen to. So you went and explored the Reunion House first for Peyton’s class. And then what?
Ye Hong 07:50
I was already thinking of what should I do for my thesis, because I wanted to bridge my two majors, and make sure my foundation is very solid, that it’s making sense to everyone, and it’s not just a thesis. It’s going to be helpful for somebody. So I’m looking for a historic property that I can explore with different technologies. And that’s the second semester of my first year. And then I talked to Sian, she was like, Yeah, of course, the Neutra studio would like students to do that work. I’m very grateful for all the help they offered me, because during my thesis, I went there three or four times, it’s like a constant going back and forth, back and forth, and to test out my methodology and technologies. And they never say, oh, you can’t come in, that’s too much. They’re always welcoming me in the property and do my research.
Trudi Sandmeier 08:53
So you picked Reunion House to be your subject site. But what question were you trying to answer using the Reunion House as your location?
Ye Hong 09:04
So my thesis title is Scanning Heritage With Smartphones: a Case Study at the Reunion House. And in this thesis, I was trying to figure out whether we can use smartphone to reach some point of documentation or serve some historic preservation tasks. I feel this idea of scanning with phones came to me when I realized that many historic heritage sites and buildings are not receiving enough attention because of the inequity in the resources. We have problems such as lack of staff, lack of funding, operational barriers.
Trudi Sandmeier 09:50
Reducing the barriers for people to be able to do this work is really important.
Ye Hong 09:56
Yeah. And I think we can keep this technology accessible enough for everyone to scan, to document, and to share what they consider valuable and significant. When I was doing this research, I was hoping that it can be beneficial for the protection of our built environment, either to have like, collective memories, or it’s significant for individuals, or for a group, and also for those sites that are physically inaccessible, or being endangered or being ignored. So for people who work on preserving the heritage, I feel like more accessible tools are needed. And maybe we can just use a smartphone that’s by our hand.
Trudi Sandmeier 10:44
So when you say I wanted people to be able to use their smartphone to document a historic site, what do you mean by that? How could you possibly do that?
Ye Hong 10:54
Okay, so right now, a historic site can be documented in various ways. You can document the sound around it, pictures, or video. And I think because I’m working right now, I feel like in our working scenario, we’re mostly using photographs from phones. And then you will have a ton of data showing on your computer. But you still don’t have the sense of how this place looks like to really understand what’s going on in that space.
Trudi Sandmeier 11:29
Right. Because those are all 2D methods that you were talking about.
Ye Hong 11:32
Yes, exactly. And also, because I know some iPhones right now they are equipped with LIDAR system. It’s a light detection and ranging system, which measures the time of the light from laser that shoot out and reflect from the surface and bouncing back.
Trudi Sandmeier 11:53
So smartphones have not always had this, is this kind of a new development in smartphone technology?
Ye Hong 12:00
I was at the point of replacing my iPhone 8. And the new iPhone 13 came out with this LIDAR system. There are several apps out available. And then I can explore the possibilities of LIDAR system on iPhones.
Trudi Sandmeier 12:20
So LIDAR is a system for creating a three-dimensional scan of a place.
Ye Hong 12:26
So it’s one light shooting out, coming back, and then create one point on that surface as a record. So we have millions of light going out and shoot back and creating that surface through a lot of points. And that’s the data file, we call it point cloud. It’s like a cluster of points, and then it creates the shape.
Trudi Sandmeier 12:51
Right. So you could use that in any room in the Reunion House and it would show you the picture of the room, all four walls and the ceiling and the floor.
Ye Hong 13:07
So in that case, I have to scan it horizontally one time, and then tilt my iPhone up and scan the ceiling one time, and then turn it down and scan the floor one time and then in my computer processing, I would merge them all together into one.
Trudi Sandmeier 13:24
As opposed to a professional scanner that does it all at once. You have to manually put them together with these iPhone scans?
Ye Hong 13:32
Yes.
Trudi Sandmeier 13:33
So what did you find when you did your research? Is it the same as using a 3D scanner when you use your phone?
Ye Hong 13:44
Wow, it’s totally different experience. And like both way of operating it and processing it and also the outcome. It’s different, it’s similar, but there’s definitely a gap in between. For professional 3D scanner, it’s very expensive to rent equipment, to rent the software, and to hire the specialists. But on a professional scanner, the user interface is very simple. You just basically click on one button and it start to scan itself. The only thing you have to do is to hide somewhere, make sure the laser doesn’t shoot on you and scan you as well.
Trudi Sandmeier 14:25
That’s right. You’re not always going to be in that room are you?
Ye Hong 14:29
Yeah, and for a smartphone, I have to set it up on a tripod. And it’s more like a video-taking experience with smartphones. So click the Start button and then you turn your phone 360 degrees around and make sure it reaches the original point and then you finish it. The smartphone have a ton of apps that you can choose. The one I choose is Sitescape. I choose it simply because it’s free for all users, and you can upload, download to their own cloud without a cost. And I think that’s my very original purpose of doing it for free. The Sitescape allows me to take multiple scans, I can pause it, and turn it off and restart it. The general result is very good. I was able to get a view of the room. So it’s a very good experience to learn how to use it. To compare the results, I overlap the professional scanner point cloud data with my iPhone scan point cloud data together. I was using this app called CloudCompare. It’s also free for download. It took me some time to learn how to use it on YouTube. But it’s fairly accessible and easy to understand. And the tool I was using can compute the distance between my iPhone scan and my professional scanner scan. And then they will generate you a bar chart show that like what’s the range of the differences. And in my case, it’s usually in zero to nine inches.
Trudi Sandmeier 16:11
So if you’re comparing the two, that’s very helpful. But you have to know that if you’re only using your phone, because that’s all you can use, it might not be perfectly accurate.
Ye Hong 16:24
Yes, yes. So we’re trying to evaluate how big the gap is. And in what situation, we can use it and in what situations it’s not recommended.
Trudi Sandmeier 16:34
So you used a couple of different apps in order to process this phone data. You used another program called Matterport. What does that do?
Ye Hong 16:44
So Matterport is a different way of scanning interior or exterior. The operation is it’s pretty similar. In this case, you take pictures 360 around and the app would stitch them together for you. There’s less control in your hand, but more control from the coding. They will do it for you. And then after several minutes, you can see it on your cloud, that they will give you a dollhouse view or say like a virtual tour experience. And you can ship the model around.
Trudi Sandmeier 17:22
And how do people use Matterport right now?
Ye Hong 17:24
It’s mostly used for real estate agents. And they took photos of different places and the the app stitched them together, and they will have a virtual tour experience for their client. So that like people don’t have to be there to see the house and they can experience interior.
Trudi Sandmeier 17:44
Right, so many of our users probably have done this, which is you can go be a looky loo in someone’s house using these 3D virtual tours that real estate agents put up on the web. So how do you think that might be helpful for people looking at historic sites?
Ye Hong 18:01
I also tried the measurements, they are kind of okay, but they are not very accurate. You cannot trust them for any research or academia research studies. But it’s good enough for people to share it universally. As long as you have internet, I can share this house with you, you can see a lot of details that photos may not capture. And also it’s very good for, as we discussed with my classmates in class, they were like, Oh, if there’s a place that is not accessible, or like it’s not ADA-approved, then it can be shared universally. And it’s equally for everyone to see it. And it’s gonna be great.
Trudi Sandmeier 18:43
Which is a big issue in historic sites, often where there’s, for instance, a second floor, but no elevator. And someone who has mobility challenges can’t get upstairs to necessarily see those places. This is a way for people to experience those second floors. Obviously not the same as being there in person, but they can get a sense of how the rooms go together and almost do a virtual walkthrough of that space that they can’t physically get to.
Ye Hong 19:11
Exactly.
Trudi Sandmeier 19:12
Is this also free?
Ye Hong 19:13
Yes. But it’s like a limited version for free that you can upload only up to three or four to the cloud. But I think if you’re only managing one property that’s good enough for you.
Trudi Sandmeier 19:26
Can you do LIDAR scanning outside?
Ye Hong 19:30
I tried. I tried an outdoor environment because the Reunion House also has a little front yard, it’s very lovely, and a little pond. If it’s heavily covered by tree canopies, I wouldn’t recommend it. The professional LIDAR scans with the laser would be strong enough to penetrate through the gaps between leaves. But smartphone LIDAR laser is not that strong. There would shoot and they kind of lose themselves. They’re like, where am I can’t go back!
Trudi Sandmeier 20:04
Right, because it doesn’t have anything to bounce off of, right?
Ye Hong 20:08
Yes, so the result is not very good. In some scenarios, if you are really out of other professional methods, smartphone is definitely a good call for you. Because we are actually able to capture some details in the Reunion House. For example, the sloped ceiling, the smartphone scan can capture that. It’s the same slope as we captured with professional scanners. We can also capture the thickness of a sliding door, just in one scan, we’re also able to capture locations of features. But if you’re trying to document a very exact shape of a detailed feature, you have to try other methods using smartphone scan instead of set it on a tripod. If you’re trying to document and generate a professional drawing like an architecture drawing, there will be a range of deviation, or the range of error.
Trudi Sandmeier 21:08
So the technology is great, but it’s not perfect.
Ye Hong 21:12
Yeah.
Trudi Sandmeier 21:12
And it’s not a replacement for a professional scan.
Ye Hong 21:16
And I think it’s very obvious a smartphone is right now is not capable of replacing the professional equipments like a 3D scanner. But I’m wishing in some of the situations, if people read my thesis and read this research, they would realize, oh, I can still use my smartphone and do that type of documentation for the site.
Trudi Sandmeier 21:50
So let’s talk again with Sian Winship about how the Neutra Institute is using Ye Hong’s research to work with some great partners like the Association for Preservation Technology, or APT and the Getty Conservation Institute.
Sian Winship 22:06
In spring of 2023 APT came and did a daylong documentation workshop, both on the different types of laser technologies, and on HABS photo documentation. From that, actually, the Reunion House was selected by the Getty Conservation Institute as their case study for their international course on Modern Heritage Conservation.
Trudi Sandmeier 22:32
So how might the Neutra Institute use scans like this?
Sian Winship 22:37
When Ye approached the Institute, she asked if there were any particular areas that we wanted to make sure she captured. And my first thought was the kitchen. The kitchen is a space that was modified over time by Dion and no longer really reflects the surfaces and materials that Richard Neutra put into the kitchen. And so as the Institute goes forward being stewards of this particular house, we need to be thoughtful about our restoration. So having this scan to capture and document Dion’s version of the kitchen may in fact be quite useful to us in the future. We have actually a virtual tour of the Reunion House that was conducted by Alan White. People who are not in Silver Lake are able to access that on the Neutra Institute website. And then people who are in Silver Lake can access that virtual tour from the public right of way via a QR code.
Trudi Sandmeier 23:34
So this prompted a whole series of things. And now the Reunion House has some kind of amazing documentation to move forward with their rehab process.
Sian Winship 23:45
Ye’s thesis definitely opened the door for the Institute to create new partnerships to foster new educational experiences and opportunities for professionals and students, and to help us in our work as stewards of the place.
Trudi Sandmeier 24:12
Tell me a little bit about what you’re doing now.
Ye Hong 24:17
After graduation, I got an internship from Historic Resources Group as a survey intern. And two months later, I got a job. I’m right now a architecture historian at Historic Resources Group.
Trudi Sandmeier 24:33
Well, that’s exciting. And congratulations.
Ye Hong 24:36
Thank you.
Trudi Sandmeier 24:36
We love it when our students get jobs. How long have you been working there now?
Ye Hong 24:41
I’ve been here since last July, so around half a year.
Trudi Sandmeier 24:46
And what kinds of projects are you working on now?
Ye Hong 24:49
Right now we are working on the Ventura Historic Context Survey. We’re also on a lot of individual projects for private clients, doing consultant for their CEQA review or doing reports.
Trudi Sandmeier 25:06
Historic Resources Group is one of the oldest firms in town and filled with our graduates, which is exciting. It’s fun to add another USC MHC student to the roster at HRG.
Ye Hong 25:19
Yay.
Trudi Sandmeier 25:21
So thank you Ye Hong. It’s been such a pleasure to talk to you about your research. Thanks for coming to share it with us here on Save As.
Ye Hong 25:29
Thank you Trudi.
Cindy Olnick 25:34
Well, thank you, Trudi and Ye and Sian for giving us that little glimpse into yet another tool for understanding our built environment and keeping it relevant.
Trudi Sandmeier 25:48
It’s a sneak peek of the future of our field when everybody just with their smartphone is going to be able to do some of this work. I think it’s really going to tear down some of the barriers that people have to getting involved in the day to day work of conservation.
Cindy Olnick 26:07
Tune in next time for a glimpse into the drag culture of Los Angeles.
Jesus Barba Bonilla 26:13
Drag’s not new. I think it’s important for people to understand this and for the people to know that there’s a lot more to uncover. And then there is a culture and there’s a whole history that helped Drag become what it is today.
Cindy Olnick 26:36
Thanks so much for joining us for this episode of Save As For photos and shownotes visit our website at SaveAs. place. You can also connect with us on Instagram at Save As NextGen. Please subscribe, review and tell a friend.
Trudi Sandmeier 26:57
This episode was produced by Trudi Sandmeier and Willa Seidenberg. Our original theme music is by Steven Conley. Additional music in this episode is from Upbeat. Save As is a production of the Heritage Conservation program in the School of Architecture at the University of Southern California.
