Nephelococcygia (Cloud Watching) for Public Outreach

One of the limitations I often face when using 3D technology for public outreach is the still very small database of models to pull from. The process for creating a 3D model of an artifact or site is time consuming and most of us simply do not have time to model everything we would like too. Therefore, it is in our best interest to find ways of making 3D technology more appealing to our peers in other branches of archaeology. For this post, I tested the CloudCompare software and found that it has a lot of potential.

Testing the Program

Recently, the American Civil War monument that I used as a subject for my first photogrammetry model was knocked over. The Sons of the Confederacy group here in Tallahassee, Florida believe that it was accidently hit by a work vehicle and was not intentional vandalism. I saw this as a perfect opportunity to test out CloudCompare and see what changes might have occurred to the monument.

The CloudCompare software overlays the point cloud you get from either photogrammetry or laser scanning the original model

on another version

to get a very nice visual comparison of the two. This is the first version using CloudCompare:

Note the blue in the center of the monument, indicating little change, and the red edges, suggesting a lot of change. For this first comparison, I aligned the base and this revealed that the marker’s position had changed (it is now set more square than before). This is something that I had missed while photographing and looking at the models separately. If you click on annotation 3 we can very nicely see the new footprint for the marker on its base. This also might explain why I could not get CloudCompare’s auto-alignment feature to work like I was expecting.

Also in this comparison you can see the two large chips (marked by annotation 1) that were removed from the base. While these show up, comparing the base is problematic as the original model had a lot of grass growing right next to the stone, and the recent version has the glass cleared away. This resulted in a lot of false positives when looking for damage on the base.

Since it was the marker that was knocked over though, I really wanted to see how that had changed. After aligning the face of the models, I got some more interesting results.

The first thing you might notice is that the top edge of the plaque and the edge of the oval on the plaque are red. I suspect that what we are seeing is one version of the models not generating this edge very well.

Annotation 2 highlights another piece of damage that I had previously missed in the form of a new notch in the marker’s edge. If you look back at the new version of the completed model, these notches look pretty uniform and this marker has been moved before. This makes me wonder if the equipment used to hoist the stone is causing this damage.

Also note that the cosmetic damage to the plaque does not show up. I was hoping that the program might track color changes as well, but you cannot have everything. Also, a chip missing out of the top-front edge that is not highlighted as much as it probably should be. I suspect some fiddling with settings should make this pop out more.

Conclusion

As a test, this monument was the perfect subject. I saw the changes that I expected to see, saw changes I had missed, and learned about some of the limitations of CloudCompare. The potential for this program as a research tool for documenting sites and artifacts is pretty obvious. However, I see a more direct use in our public outreach programs as well.

In particular, the Florida Public Archaeology Network has a program called Heritage Monitoring Scouts where we are organizing public volunteers to help monitor coastal sites that are threatened by sea level rise. If we were to train certain volunteers to take pictures for photogrammetry purposes, we could use CloudCompare to help document the degradation of these resources over time. This would be very useful information and I suspect that participants would find it rewarding as well.

Any other ideas? How would you use this software?


Tristan Harrenstein is trained as an archaeologist and has a passion for outreach and education. This is fortunate as he is also an employee of the Florida Public Archaeology Network, an organization dedicated to promoting the preservation and appreciation of our archaeological resources. He shares a blog space with his boss (Barbara Clark) and you can read more blog posts on other archaeology related subjects that tickle our fancy here.

A Giant Ground Sloth is 2 ½ Fourth Graders Tall

By Bernard K. Means, Director, Virtual Curation Laboratory at Virginia Commonwealth University

Go to any public archaeology event or even an academically oriented archaeology conference, and you will probably see at least one button, shirt, or even a ball cap emblazoned with an image of a dinosaur (probably a Tyrannosaurus rex) contained within a thick red circle and bisected by a thick red line.

Below or surrounding that image might be the words “Archaeologists Don’t Dig Dinosaurs.” I use this image myself on my first day of lecturing in my Introduction to Archaeology course each semester. One of the basic messages that I try to impart on that first day is that archaeologists are not paleontologists.

3D scanning a bone from an enslaved context at VMNH pictured is Dr Elizabeth Moore
3D scanning a bone from an enslaved context at VMNH pictured is Dr Elizabeth Moore. Image by author.

We might like dinosaurs or other prehistoric animals, but if those animals lived before or did not interact with humans or their hominid ancestors, those “terrible lizards” and other ancient creatures fall outside of our purview. I also warn any budding archaeologist that they will get asked, probably by a relative and certainly by a member of the public, if they have “found any dinosaurs yet?” after their first, second, third, ad nauseam, dig.

However, I’ve begun to rethink over the last few months that image of the dinosaur struck out in red.

This reassessment of the phrase “Archaeologists Don’t Dig Dinosaurs” has grown out of my work in the Virtual Curation Laboratory with various natural history museums, notably the Virginia Museum of Natural History (VMNH) in Martinsville, Virginia, the Western Science Center (WSC) in Hemet, California, and the Las Vegas Natural History Museum (LVNHM), not surprisingly in Las Vegas, New Mexico.

Beginning at VMNH, I found fossils creeping into what I 3D scanned. Paleontologists at that museum asked if I would not mind scanning the occasional fossil in between artifact scans, such as Miocene whale vertebrae, a lungfish bone from Chile, or various Ice Age animals. In fact, for VMNH right now, I am 3D printing mirrored 3D scans of giant ground sloth bones—VMNH has lefts and rights and needs rights and lefts.

3d scanning a prehistoric camel skull at WSC
3D scanning a prehistoric camel skull. Image by author.

I’ve actually been 3D scanning and 3D printing quite a few Ice Age animal bones over the last year. In addition to the aforementioned giant ground sloth bones from VMNH, I have 3D scanned giant beaver (VMNH), mastodon (VMNH, WSC, and a private collection), mammoth (VMNH, WSC, LVMNH), short- faced bear (WSC), American camel (WSC, LVMNH) and dire wolf (LVMNH)—yes dire wolves were once real and not just something made up for Game of Thrones. These animals are all now extinct—and these fossils do potentially represent an overlap between archaeology and paleontology as these animals all lived at the time after humans entered the Americas. Some scenarios even argue that humans are partly or solely responsible for the extinction of these Ice Age megafauna (e.g. big animals!). But, the dinosaur bones I 3D scanned at LVMNH or the dinosaur tracks I 3D scanned at VMNH well predate the presence of humans in the Americas or anywhere across the globe, as dinosaurs went extinct millions of years before humans first evolved.

3D scanning an allosauroid vertebra at LVMNH
3D scanning an allosauroid vertebra at LVMNH. Image by author.

 

So, why bring up dinosaurs, or even the fossils of Ice Age animals from contexts not associated with human activity? This is because I increasingly find myself in settings that are less archaeology oriented, but more focused on how 3D technologies—particularly 3D printing—can help inform the past. And, I am talking to audiences that are generally interested in the past—whether the human past or an even deeper past. I want to encourage and celebrate this interest, this fascination with science, and not be quite so pedantic about, ”Well, no, I don’t do dinosaurs, ask someone else.” Paleontologists, as well as archaeologists, are also interested in public outreach and share our goal of teaching people about the past—our disciplinary differences are important, but I think we need to sometimes blur these boundaries.

3D scanning maeve foster
Scanning Maeve Foster.

Which gets me to the title of this blog. On May 1, 2017, I was invited to speak to the soon-to-be retired Judith Fitzpatrick’s fourth grade class about applications of 3D printing, and I brought along a wide selection of recent 3D prints, including artifacts from Pennsylvania, Virginia, and India, animal bones from archaeological and modern contexts, and various fossils, including a giant ground sloth claw. I also had with me a 3D print of a 4th grader—Maeve Foster—who had interviewed me the previous month for her class, as she is interested in 3D printing. Maeve was out ill that day, but her fellow classmates were fascinated that she was there in miniature 3D-printed form, and they placed her figure on her desk. The students really liked the opportunity to handle the replicated objects, and to discuss their significance.

3D printed giant ground sloth claw
3D printed giant sloth claw. Image by author.

 

maeve foster 3D
3D printed Maeve Foster. Image by author.

They were also glad to find out that they could download and 3D print some of the objects from our Sketchfab site. One of the items that I passed around that was of great interest was a 3D printed giant ground sloth claw, 3D scanned originally at VMNH. A young 4th grader asked how tall giant ground sloths were, relative to 4th graders. 4th graders not being a standard measure in archaeology or paleontology, I asked if one of the students would offer up their height. A young girl quickly stated that she was 4 feet tall. So, this makes the extinct giant ground sloth 2 ½ 4th graders tall.

setting up 3D prints at Short Pump elementary school
Setting up 3D prints at Short Pump Elementary School.

I certainly think the future of public archaeology—and public paleontology—as well as educational applications will be found in the chirping and beeping of the 3D printer. For more on educational applications of 3D printing, I refer the reader to this recent blog: Enhancing archaeological research with 3D printing.


In the Virtual Curation Laboratory, a team of Virginia Commonwealth University undergraduate students and alumni works under project director Dr. Bernard K. Means to digitally preserve the past and share it with the world. Check out and download digital artifact models on our Sketchfab page.