Last week we published a story about the Smithsonian’s recent massive release of digital data, but the apparent lack of 3D models. 

It turns out there are indeed some 3D models in their archive, but it takes a bit of detective work to find them. 

Searching Smithsonian 3D Models

I had spent some time on the site’s search page attempting to locate files with associated 3D models. There should be some, as the release apparently included material for 2.8M artifacts in the Smithsonian’s extensive collection. 

All the entries I inspected simply offered fine 2D digital images of the object. While that’s entirely suitable for paintings, it’s less interesting for 3D objects. Some entries offered multiple 2D views of objects, but in my searches I could not locate any new 3D models. 

Alternative 3D Search Strategy

Evidently I should have been more sophisticated in my search approach, as an astute reader was able to find some 3D models. Tom O’Mahoney provided this response:

“…A quick search using the term .ply on si.edu/openaccess yields 2171 results. Searching with ‘3d’ gives 2212. I imagine filtering through the github/AWS interfaces will generate even more, as you would be able to dive a bit deeper.”

O’Mahoney used a different search strategy than I had by literally searching for file suffixes that indicate a 3D file. “.PLY” is a 3D model file format, originally created at Stanford. It is similar to the more common .STL, but can include color texture information. 

Given O’Mahoney’s tip, I resumed my searches with a bit more aggressiveness and a different strategy. However, if you search for “.PLY” you get nothing. If you search for “PLY”, you also get nothing. If, however, you search for PLY (without any quotes), you will find some items. At the time of my search, there were 2137 hits for this term in the “3D” category. 

Smithsonian 3D Models

The Smithsonian categorizes results into different types of media, including Websites, Images, Exhibitions, Stories, Videos, and “3D”. 

And voila, there were results. The first results seemed to be a series of 3D scans of bone fossils from curious creatures such as “Hapalemur griseus griseus”, “Pongo abelii” or “Pan troglodytes troglodytes”. The last is, in fact, a Chimpanzee. 

However, the search results are an endless series of individual bones. A better search might be: “PLY Gorilla” (without quotes, obviously) that provides a list of all Gorilla bones that are apparently available in 3D PLY format. I could not check all of the files, as there seem to be hundreds — and for more than one Gorilla, as we can see here: 

The individual entries show the tombstone information for the object, as well as an interactive 3D display that can be used to show all sides of the object. Note the license displayed is “CC 0”, meaning public domain. However, at the bottom of the 3D display is a tiny download button: 

If you touch that button, you’ll get a list of the 3D files that can be downloaded. For this particular Gorilla cranium, there was only a “Full Resolution 3D mesh, ply, scale in mm”. The problem is that the Smithsonian doesn’t tell you how big the files are.

From downloading a few 3D models, I can tell you that anything they say is “Full Resolution” means big. Really, really big. This Gorilla 3D model is 155MB and 750k faces. 

This 3D model, of a whale fossil still embedded in rock, is literally 2.8GB in size. That’s so huge it is unlikely to be sliceable on typical 3D print management software. It’s also so detailed that any 3D print would likely lose some of the finer structures. 

Smithsonian 3D Model Count

But are there other 3D models in the collection? I tried a number of similar searches. For “STL” there are only three results: two versions of the Apollo 11 command module hatch, and a Mammoth. The Mammoth is available only in STL format, while the hatch can be downloaded in:

• Blender

• Fusion 360

• STL

• OBJ

• GLTF

• GLB

As well as both full or low resolution. Some entries also offer a medium resolution. A low-resolution Space Shuttle 3D model, for example, is “only” 27MB and 150K faces. 

Many of the OBJ 3D models I downloaded contained color texture information, but Meshlab is unable to open them, leaving you with an uncolored result. Some did work, however, but be prepared for non-colored 3D models.

What this shows is that the file formats and sizes of 3D models varies considerably in the Smithsonian’s collection. Here’s my search results for various 3D file formats:

• STL: 3

• PLY: 2137

• OBJ: 67

• F3Z: 2

• 3D: 2213

I take this to mean they have just over 2200 3D models available for download. It’s not clear whether “3D” is a keyword that actually denotes a 3D model, or whether there is only a 3D view. Or both. 

Many thanks to O’Mahoney for putting me on the right track to search this valuable archive. However, it wouldn’t hurt for the Smithsonian to simplify the search method for those seeking 3D models. It’s a bit tricky now as it really requires you to have knowledge of multiple 3D file formats. 

Via Smithsonian