Dear Editor, dear authors,

It was a pleasure to read the article titled “V3Geo: A cloud-based repository for virtual 3D models in geoscience” written by Simon John Buckley, John Anthony Howell, Nicole Naumann, Conor Lewis, Magda Chmielewska, Kari Ringdal, Joris Vanbiervliet, Bowei Tong, Oliver Severin Mulelid-Tynes, Dylan Foster, Gail Maxwell, and Jessica Pugsley. In this article they present a tool/platform to make 3D geological data accessible for example for teaching, but also accompanying publications and just as shared data. The article is well written and without being aware of this upcoming publication, I actually used the V3Geo earlier this year to publish data for a publication. Hence, I first hand experienced the workflow and can confirm the suggested user experience in the article.

Nevertheless, I do have two minor comments (accepted subject to minor revisions), which I would like the authors to address:

• Could the authors clarify what the difference (advantages/disadvantages) are between e-rock? Since e-rock, seems to be a very similar to V3Geo and thus in disagreement to the authors statement: “Although these studies highlight the practical benefits of web-based sharing of 3D models in geoscience, no current single repository has been presented for scientific and professional purposes. Solutions are limited in file (and therefore dataset) size, precluding many of the details needed for interpretation, do not allow supplementary interpretations or datasets, or are too broad in scope, covering all areas of society rather than being tailored to the geoscience community” (Line 72-75) Regarding the interpretation pf data sets – V3Geo seems to me from a user perspective not yet different to other solutions on the market. Is the data interpretation only possible via Lime or did I overlook some of the features. Please clarify.
• The authors mentioned the V3Geo platform has been designed to handle different scales of model (microscopic, hand specimens, outcrop, etc. (See Line 11-12, 26-27) However, the text is only talking about outcrop-models. Will the focus stay on outcrop models? Will V3Geo take at the same time hand samples into account, making it more similar to e-rock? Similar, what about the microscopic scale? Are these mentioned, because the platform could be used as a framework for similar data platform related to microscopic samples? Please explain, why the mention of microscopic when the text is all about outcrop scale?

Best regards,

Tobias Schmiedel

This manuscript introduces an online repository for 3-D photographic models, aimed for research and science education, that additionally allows for user interaction and inspection. Thanks to advances in and wider availability of digital capturing techniques, 3-D photographic models are becoming a standard tool in field-related studies. Providing an online community repository is therefore a very useful and timely service. Once used and populated with more content, the platform has the potential to become an integral resource and tool to the wider Geoscience community. The platform’s long-term viability, which is key in such a context, is discussed and clarified to the user. The manuscript is written very well and nicely illustrated. Whether the manuscript fits the journal’s scope is up to the editor(s), but I highly suggest that Geoscience Communication also publishes manuscripts introducing community tools like this and not only research-based work. I therefore recommend this widely useful work for publication after some minor revision.

Could it be clarified whether updates (of faulty data) or extensions (with additional related data) are possible at all, and whether those would be traceable by the users (e.g., via versioning)? Similarly, could a dataset be made obsolete, if another, better/newer one is published (to avoid duplication, continued use of outdated data, and save storage space)?

Adding a short, simplified guide for unexperienced readers to the manuscript to explain how a 3-D photographic model is created (starting from standing in front of a sample/outcrop), is not key to the paper, but would, I think, be useful to promote their wider use and give unexperienced field geologists a feeling about whether they could use this tool too, or not.

Line 9: Being a geodynamic modeller, reading the title and first sentence, my first impression was the manuscript being about an online repository of physical models of the Earth. I guess other readers with yet another background might understand it to be about conceptual models. Given that you have a rather wide audience in this journal, maybe it would be worth clarifying the term ‚model’ early on at the beginning of the abstract, by using a term like “3-D photographic models“ or similar?

Lines 30-37: Is the use of 3-D photographic models also bringing down field-work costs in general (by reducing the work force and time in the field)? If so, would that be another very good argument to mention here?

Lines 50-54: Out of interest: Is that a similar approach to the quadtree used in e.g., Google Earth?

Line 224: Consider clarifying to: „several gigabytes of model data“.

Thanks for this excellent work!

Fabio Crameri 

5.12.2021