Tag Archives: 3D

Fun with SFM – part II: The results

So, hello, dear all, I am back from a very busy family weekend – and I would like to entertain you now with our second part to our SFM-tutorial!

Due to my work at University, I have the opportunity to work with Agisoft Photoscan, which is quite the same as Agisoft Metashape. You can find all the information on this software here – I am very used to it, it is very easy to work with, very easy to understand and you hae all the features collected in one software. Of course, there are other softwares, even a lot of freeware for 3D modelling – I used to work with them as well and I think, the next step will be a comparison of the different softwares by modelling the same object. I am just looking for the time to do it, because: My dissertation has to be (okay, should be) finished by December… so, time is really rare in my life right now…

But this post is all about my little Eros/Amor riding his hippocampus. You can find the information on this example here in my first post.

I opened Agisoft Photoscan and loaded all the images I wanted to use meaning all the pictures I have taken. The first step is the aligning of the images. The software searches for the same points on different photos and matches them.

Step 1: Aligning the photos
Step 2: Building the point cloud

The next step will be the point cloud – of all the points that the software could match on different photos (the best thing is that you get the same point at least out of three different directions) there will be a so-called point cloud as a result. As you can see in the second pic here, there are a lot of “noises” around my object – you can barely recognize Amor’s foot an the tail of the hippocampus.  So, the next step is to clean this mess up. You just mark all the noises around your object and delete it. Another possibility is to mask your photos before aligning them and starting to build a point cloud. Either step will take its time.

In my first post I mentioned the different directions you have to take the pictures from. Here is a screenshot of all the thumbnails of my pics, just to help you geting an idea.
And again, the front view of my model, here already “meshed”.

So, after cleaning you will get a very nice point cloud showing just your object. I just took the side view of this sarcophagus, so my object remains quite flat with no other sides.

After the last step – the finished model!
In detail and without texture the model consists of a grid that connects all the points with each other and gives the actual shape of the surface.

After building the so-called dense point cloud (you may notice the features of the relief getting clearer), we can start with the last step – to build the actual model. As you can see here, I really tried quite hard with the texture as well. The texture can be build out of all the coloring information you have in your pics. This step is not necessary, if you are just interested in the shape of the surface. Therefore, you will get better results without coloring your model, because your eyes might get betrayed by all the shades and colors.

If you want something nice to show your students or your friends, then go for the texture. 😉

Of course there are further things to do on Agisoft Photoscan/Metashape or with other software – it’s a playground, so feel free to try. And remember, I took these images with my phone camera, so no pressure on that. Of course, your first tries may suck, but hey, it’s a process. I am still learning too and I am still discovering new fascinating features and possibilities.

I hope you enjoyed this little post – stay tuned, keep calm and start 3D modelling. 🙂

All the best,

Astrid

The “D”- and the “H”-part

It was a post of my dear LaTeX ninja, talking about the pros and cons (okay, basically the pros) of one getting started doing Digital Humanities (you can find the original post here). I just flipped through it, until the following sentences:

Because the whole point of DH is that you’re not either a programmer XOR a Humanities scholar. It’s the combination of both. Most people see that combination as some sort of 30/70 or 40/60 kind of thing. I think it has to be 100/100. And yes, that means you’ll have to be a freak with a 200% workload. I’m pretty alone with this opinion, however, so don’t panic. Most people don’t see it like that at all.  I’m generally a bit of an eccentric and maybe some might perceive my opinion to be extreme. Well, sorry, but I like extreme. I think that “real DH” should mean 200%, or even better: 300%. 150% programmer and 150% Humanities. Be hardcore at both. At least that’s my personal goal.

So, I learnt that she is somehow extreme and liking it, what I actually always thought about her, and I learnt that 100/100 is a quite ambitious goal. And then I started thinking about myself and my abilities in DH. I splitted it up, there is an “D”-part and an “H”-part. So, I would like to start with my “H”-part, meaning the humanities, basically Archaeology and Classics. I am archaeologist by training, as well as ancient historian. I sometimes like my description of myself as an archaeologist with “special features”. You know, coming from a field dealing with images, but also able to read ancient sources (well, of course, all my colleagues are able to read, but I discovered that many historians and philologists keep thinking that an archaeologist just does not use written sources –  or at least, in the wrong way).

But my special features are not just my “reading skills” all alone. I did some courses in linguistics and in geomatic engineering as well, some workshops on digital methods in the humanities, …

So, if the “H”-part, meaning my archaeology-me by training, is 100%, because I have a degree and doing my PhD, then how does my “D”-part look like?

My first tries with SFM – I worked with freeware and was amazed by the quality. Here you can see a relief side of a sarkophagus with some holes, because my photos were not that good.

I told Sarah that my “D” part is about 24.6%. The workshop on Digital and Practical Epigraphy in London (click here to read the whole post) increased my knowledge about 4.2% (don’t get me wrong, it was a 100% success, but a 100% in my “D”-part are standing for a degree, so I had to convert it). So, we are located at 28.8% by now. The moment I can run my first Python scripts in a way the are meant to run and work out, I think, my rating will increase up to 36.9%. 🙂 Cheers to that, I think.  I am convinced that this is a great number, for the sum of 3 and 6 is 9… Isn’t that beautiful? Okay, enough with the maths.

Then I thought about which part is more important to me. Basically, this is like the question, if I like bones or late antique Church Fathers the most. I cannot decide, so it is quite unfair. I need both parts, never mind how much percent they have. I am convinced that my archaeology-part is sometimes at 120%, 20% are just crazy happiness, e.g. because I am allowed to take photos in a museum on monday (so, when all museums are normally closed and it is just me and the artefacts). Sometimes ist about 84,7%, because I am that exhausted after a very concentrated climbing session or my fitness workout. My “D”-part is like a static shadow behind my the “H”-part, smiling on the archaeology-me playing with bones or being fascinated by stones. The “D”-part does perfectly know that its whole existence is mainly about my archaeology-me letting it be. So maybe the “H”-part is first place in a hierachical structure. The “D”-part comes second and is caused by the “H”-part. Does sound like some kind of splitted personality, am I right? (Just a reminder: Yes, we are all crazy here, trust the Hatter, I tell you that).

My photos are better, my knowledge of the software has increased. But still, there are a lot of “mysteries” for a happy noob like me. And I like mysteries. 🙂

So, if I had never ever found the idea of being able to do SFM and 3D-stuff fascinating, if I had never ever the interest in photography, I would never ever have ended up this way. I am a trained archaeologist, capable of mastering the “H”, and a proud and happy noob, dealing with and experiencing the “D”, while learning on the job. I think, this is a very good mixture.

What about you? What is your “D” to “H” ratio? How are you working on yourself and your skills?

All the best,

Astrid (currently 28.8%/105% – because I could post some of my screenshots of my SFM-journey…) 🙂

London calling …

Workshop on Digital and Practical Epigraphy
(London, April 29–May 4, 2019)

As you might have seen on our Twitter or Instagram-Account, I spent a week in London, participating at a really interesting workshop. It caught me while flipping over some homepages on epigraphy and classics in february this year. I was working on my catalogue for my thesis back then and somehow really frustrated about the fact that some archaeologists have no idea about epigraphy at all. Well, there are also some epigraphists who do not think inscriptions are archaeological material either, … So, it is time that we change this view, don’t you all think so?

I want to show my network and the people around me that (mainly) stones with letters on them are far more interesting than any epigraphist or archaeologist has ever thought of before. And because of that I decided that it is time to show the world my fascination. And as an archaeolgist, I use pictures for sharing my research, before I use words. And, good thing for me, this workshop was actually on taking pictures of inscriptions – or, so to speak, different methods to produce images and/or a proper documentation of inscriptions.

So, what did I learn at this particular workshop?

We started with the various methods of documenting inscriptions. And we really started from scratch, talking about the method of making squeezes (basically pressing and smashing wet special paper on a wet stone by using a great brush – acutally you can watch a video on how to do it here), about taking drawings of the inscriptions and so on. We talked about printed epigraphic ressources as well as about online sources.

We had a very interesting introduction to photogrammetry as a method of documentation for inscriptions. We tried it out at the wonderful St Pancras Gardens – next to making squeezes, we had to pick one stone of our choice – I decided on a little broken one who stucks in the earth and has a pretty angel face on it. We took the photographs wth our smartphones. This was completely new to me, for I am used to my DSLR camera – but I was very surprised to see my results after the whole aligning, dense cloud building and mesh building on Agisoft Metashape (looks quite the same like Photoscan, does the same, feels the same – at least for me).

As you can see, it does look really nice…

After our work with 3D-models and squeezes, we got into the “serious” DH-stuff… I am talking about TEI, EpiDoc and EFES (EpiDoc Front End Services, which is a custom and a platform for publication and search/indexing of EpiDoc files). I have heard the terms “TExt Encoding Initiative” and EpiDoc before, of course, I knew that there was something about coding and tagging and XML, but how all these things are really connected, never ever came clear to my mind, because I simply never ever had the time to read through the amazing amount of information on these things.

Basically, it is a way to encode your inscriptions with all the metadata and information you have about them (e.g. finding spots, description, the museums where it can be found today, transcription etc.) in XML and to make them accessible online on a database or website of your project. There are many different projects running on these kind of scheme, just scroll through the short Wikipedia entry on EpiDoc and click on the various links!

Coding means “keep the cookies coming” – and thank God they had really tasty cookies there. And coffee. Now I finally understand all my friends who work as programmers…

The people behind EpiDoc which gave this workshop are very interested in getting people to know about their project and sharing their knowledge on how to get inscriptions online to make them accessible and useful for science and research to happen. So, go ahead and inform yourself on the various possibilities of participating at a workshop where you can learn the basics of EpiDoc!

… and EFES, of course. This is one of my first tests with EpiDoc files I had to run on EFES, and it worked – it may not look that aesthetic, but, hey, it worked out the way I wanted it too!

By the end of the week, I have to admit it, I was really exhausted. There were so many new things criss-crosing in my mind, it took me nearly four days to recover my brain… For now, I am busy trying to summarize my notes and to work them through again, just making sure not to forget anything important. I hope that soon I can find the time to write more extensive posts on the single methods I learned about.

For now, it is just a very short summary on this amazing week.

I hope you enjoyed this little overview –

take care!

Astrid/archaeogirl