USING PHOTOGRAMMETRY TO CREATE VIRTUAL HAND SAMPLES

In order to work within university proceedings during the COVID-19 pandemic, one geoscience course at The University of Texas at Dallas utilized photogrammetry techniques to create interactive models of hand samples used during the typical lab section. A major challenge when teaching Geoscience online is the inability to provide students with hand samples, so the virtual hand samples provided a reasonable alternative. While high-resolution photos of samples could have been used, a more realistic lab experience was desired.

There were two main steps to create the virtual samples: 1) take 360° photos of the hand sample at 3-4 different angles (the author used an Orbitvu Alphashot Micro for this), and 2) import the photos into a photogrammetry software to “stich” images together (the author used Agisoft Metashape Professional for this). After the virtual sample was created, the file was uploaded to Sketchfab (a website where individuals can publish 3D content) so students would have access to them.

It took ~60 minutes to create one virtual model. The majority of this time was due to computer processing. Additionally, while it is possible to take photos of the samples with just a tripod and a camera- the Orbitvu Alphashot Micro made the imaging process much faster. The downside to using the Orbitvu is that it can only be used for small samples (nothing bigger than the size of your hand) and if the sample has been polished or has many reflective minerals it usually will not photograph well due to the intense lighting that the Orbitvu provides. There may be a way to work around this, but the author did not explore this.

During an informal survey, students felt the virtual samples were useful for certain labs but preferred the high-resolution pictures for others. Students reported that the high-resolution pictures were more useful during labs which asked students to observe micro aspects of samples (such as grain size, matrix, etc.), and found the interactive virtual samples more useful during labs which asked students to make observations about macro aspects of samples (such as identifying ichnofacies, sedimentary structures, and rock descriptions). Overall, the students reported that they liked the combination of virtual samples and high-resolution pictures for completing labs and that the combination was better than either alone.