(Originally published 12/11/20)
For my first photogrammetry “experiment,” I quickly tried out several options for free photogrammetry software—3DF Zephyr (Free), Autodesk ReCap Photo, 3D Regard, and Meshroom—along with one $5 iOS app, Trnio. For each, I used the same set of 32 images of a deer antler.
3DF Zephyr Free
Windows only — Free desktop software, runs faster w/ CUDA-enabled GPU but took less than an hour to process model. Interface navigation & overall ease of use = fairly easy to moderate (w/ tutorials). Nice detail on resulting model, but did not capture tips of antler on first try.
Autodesk ReCap Photo
Windows only — Autodesk offers a free educational license to teachers and students. The resulting model looks great—lots of detail, and the antler points are captured. Unfortunately, the free version makes you wait in a queue while the model processes on Autodesk’s servers. Processing 32 images took me 10-18 hours (had been stuck at 99% for hours by 11 p.m. when I went to bed) but it was done when I checked it again at 8 a.m. Lots of people on their message boards are furious about wait times, so wait times of 12+ hours are to be expected. (Not a great choice for a student—or anyone—on a deadline!)
Windows & Mac — This one surprised me. The interface seemed surprisingly simple (though did have to track down camera sensor size for my images). The point cloud didn’t look right, and I was about to give up. But then I went back and created the dense mesh and surface texture… (At that point I was able to export the .obj file as well.) The resulting model ISN’T GREAT–there doesn’t seem to be as much detail as on the models, and there are some patchy spots–but given the right object, this software could do the trick.
Windows only + must have CUDA-enabled Nvidia graphics card — User-friendly interface, but moving models in 3D space (as w/ all software explored here) = a little challenging at first. Model looks good! (My colleague John LaShomb may have additional notes here–as he produced this model–and attached screencast–using the same 32 antler images.)
Mobile iOS app, $4.99 one-time purchase — This one isn’t free, but after frustrating initial results with the free software options, I figured I’d splurge on this app–if only to be able to compare the results. The user interface is VERY user-friendly and fast. While the final model isn’t perfect, I was very happy with it (it was the best of the models I was able to create). I should note here that I created 3 models of the antler using each of the 3 “modes” that Trnio offers. 1.) “Import” pre-existing images on your phone (I used the same 32 antler images for the other software), 2.) “Object Mode” for walking around your image and photographing (Trnio maps it out as you walk), or 3.) “Arkit Mode”–which Trnio says is the fastest and easiest mode for producing 3D models. The “Import” mode produced the best model by far (w/ “Object” producing the second-best). Of course, more experimentation is in order.