This post originally appeared on Emily Crawford’s website.
Model With Filled Hole No Texture (2) by emilylynn on Sketchfab
I chose to 3D scan the Moche Sacrifice Pottery piece through a photo scanning process called Photogrammetry. This software takes a systematic set of photos with the key goal of achieving a 2/3 overlap between the original piece and what 3D model is produced. I learned that this process could be described as rather tedious and specific, but it is something that anyone with the proper equipment could do regardless of technological skill. All I had to use was my camera phone! I just had to make sure that proper lighting was established so that there wasn’t any reflections that distorted the depictions on the model. Once that was finished, all I had to do was set the pottery piece on the table and begin taking a series of photos every 10-15 degrees around the object. First, I took a series of photos with the object sitting vertical on the table. Then, I laid the piece horizontally and took another series of photos going 180 degrees over the object. This part was especially important since the curves seen at the top of the pottery piece can easily distort images that are vital to preserving the cultural heritage of the object. All in all, the photo taking process took around 1 hr and 15 minutes. After I collected 196 different photos of the Moche pottery piece, I then uploaded them to a software called Agisoft metashape. Agisoft is the software that gathered the data points from the images in order to build what is called a “point cloud”. Essentially, the program looks at the photos, finds similarities between the points, and does trigonometry/ calculus in order to find where the points actually are in space. The Agisoft processing took the longest by far, with the process taking a total of 2 ½ hours to complete. After the processing was completed, the object appeared! However, since the software captured more than just the object, such as the table and walls, you can see the tiny black dots that appeared surrounding the Moche pottery piece (pictured below).
These excess data points need to be deleted because it wouldn’t produce an accurate 3D model of the Moche Sacrifice piece if not. In order to do this, I used the mouse to turn the object 360 degrees while deleting all the excess data points. I found that this was surprisingly fun, especially if you like doing work that requires precision. This entire process took around 1 ½ hours to complete since it’s easy to accidentally delete parts of the object due to its 3D feature. Once all the excess points were deleted, the model was ran through processing one final time in order to create what is called the “dense point cloud” and “mesh” of the model. This is important because it is what makes it possible to make the texture super clear, as well as closes any “holes” (missing data points) within the Moche 3D model.
I learned so much through the 3D scanning process! Not only did I learn a lot about the Photogrammetry and Agisoft software, I also was able to see first-hand about both the pros and cons to using 3D scanning to recreate cultural heritage models and preserve cultural heritage. For starters, creating replicas of 3D models are not completely accurate. Not only can data points of the model be accidentally deleted, but the processing softwares are estimating where these points are in space. Therefore, it cannot produce a 100% accurate representation of the cultural object. This is problematic because “inaccurate reconstructions can mislead the professional and lay public unless identified as such” (The Problem with Printing Palmyra, Khunti). Another issue is capturing the correct color and texture since certain lightings can produce a slighting different color than the original. On top of this, again the software is refining color and texture points by estimating where they are in space, so it won’t be producing a completely accurate 3D model. Producing reconstructions that are unrealistic in nature makes it easy to misinterpret certain elements that are vital to preserving the cultural heritage of the object (Ancient Athens 3D). This is especially significant in regards to the Moche piece considering the fact that Moche pottery purposely used specific colors when creating their pieces. However, I still learned about many benefits to 3D scanning cultural objects as well. For example, you are able to walk around virtually anything and use a camera phone to capture photos to run through photogrammetry. This means you don’t necessarily need a super expensive camera, and you don’t have to lug around a ton of equipment. In addition to this, 3D printing allows even those who don’t have access to the proper materials to learn about said cultural heritage due to its ability to be accessed anywhere. Lastly, it’s a process anyone would be able to learn given they had the correct resources. This is extremely important because it increases the amount of people who can participate in the process of cultural heritage preservation instead of just those within the dominate north.
Archaeologists who have worked in northern Peru have found that the victims of sacrifice seen within Moche Sacrifice pottery represent “either local Moche warriors defeated in ritual battles or enemy soldiers captured in warfare with nonMoche or competing Moche polities” (Sutter & Cortez). All of the depictions within the Moche Pottery piece are significant because within the Moche culture they believed that “the sacrificial act can be thought of as expressing a dependent relationship between humans and mythical beings” (Hocqueghem). The exchanges are understood as acts of submission to these mythic beings in exchange for safety from the being’s wrath. You can see this within this 3D reconstruction above with the warrior presenting a drink to the mythical bird-like creature on it’s right while it sticks out its long tongue. The types of objects that they sacrifice are important as well. It is supposed that sacrifices will be “received better” if they are of higher value, and this is made to be representative of human nature as a whole. Contextualizing and understanding aspects like these are extremely important when creating 3D models of cultural heritage objects. If someone recreating the piece doesn’t understand how important these aspects are then they may not be as cautious to ensure the accuracy of the depictions, which in turn would take away from its meaning as a whole. Also, reconstructing cultural objects is not just about technological advance, but rather actually preserving the culture of the object. If these significant details are ignored then that becomes impossible.
Bibliography:
RosaJ.Cortez, RichardC.Sutter and, et al. “The Nature of Moche Human Sacrifice : A Bioarchaeological perspective1: Current Anthropology: Vol 46, No 4.” Current Anthropology, https://www.journals.uchicago.edu/doi/10.1086/431527.
Hocquenghem, Anne Marie. “2. Sacrifices and Ceremonial Calendars in Societies of the Central Andes: A Reconsideration.” De Gruyter, University of Texas Press, 3 Nov. 2021, https://www.degruyter.com/document/doi/10.7560/718678-004/html.
Source: Moche Pottery 3D Model
